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Development and Evaluation of an Electrical Engineering and Math Curriculum Module for High School Students

Description

Parents in STEM careers are more apt to guide their kids towards STEM careers (Sherburne-Michigan, 2017). There are STEM programs and classes for students who are interested in related fields, but the conundrum is that students need to be interested

Parents in STEM careers are more apt to guide their kids towards STEM careers (Sherburne-Michigan, 2017). There are STEM programs and classes for students who are interested in related fields, but the conundrum is that students need to be interested in order to choose to participate. The goal of this creative project was to introduce engineering concepts in a high school class to reveal and investigate the ways in which engineering concepts can be successfully introduced to a larger student populace to increase interest in engineering programs, courses, and degrees. A lesson plan and corresponding materials - including circuit kits and a simulated ball launching station with graphical display - were made to accomplish this goal. Throughout the lesson students were asked to (1) use given materials to accomplish a goal, (2) predict outcomes based on conceptual understanding and mathematical calculations, (3) test predictions, (4) record data, and (5) analyze data to generate results. The students first created a simple circuit to understand the circuit components and learn general electrical engineering concepts. A simple light dimmer circuit let students demonstrate understanding of electrical concepts (e.g., voltage, current resistance) before using the circuit to a simulated motor in order to launch a ball. The students were then asked to predict the time and height of a ball launched with various settings of their control circuit. The students were able to test their theories with the simulated launcher test set up shown in Figure 25 and collect data to create a parabolic height versus time graph. Based on the measured graph, the students were able to record their results and compare calculated values to real-world measured values. The results of the study suggest ways to introduce students to engineering while developing hands-on concept modeling of projectile motion and circuit design in math classrooms. Additionally, this lesson identifies a rich topic for teachers and STEM education researchers to explore lesson plans with interdisciplinary connections to engineering. This report will include the inspiration for the product, related work, iterative design process, and the final design. This information will be followed by user feedback, a project reflection, and lessons learned. The report will conclude with a summary and a discussion of future work.

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2018-05

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Structure-function study of N-isopropylacrylamide copolymers with enzyme degradable GAPGLF and GAPGLL side chains

Description

With an increased demand for more enzyme-sensitive, bioresorbable and more biodegradable polymers, various studies of copolymers have been developed. Polymers are widely used in various applications of biomedical engineering such as in tissue engineering, drug delivery and wound healing. Depending

With an increased demand for more enzyme-sensitive, bioresorbable and more biodegradable polymers, various studies of copolymers have been developed. Polymers are widely used in various applications of biomedical engineering such as in tissue engineering, drug delivery and wound healing. Depending on the conditions in which polymers are used, they are modified to accommodate a specific need. For instance, polymers used in drug delivery are more efficient if they are biodegradable. This ensures that the delivery system does not remain in the body after releasing the drug. It is therefore crucial that the polymer used in the drug system possess biodegradable properties. Such modification can be done in different ways including the use of peptides to make copolymers that will degrade in the presence of enzymes. In this work, we studied the effect of a polypeptide GAPGLL on the polymer NIPAAm and compare with the previously studied Poly(NIPAAm-co-GAPGLF). Both copolymers Poly(NIPAAm-co-GAPGLL) were first synthesized from Poly(NIPAAm-co-NASI) through nucleophilic substitution by the two peptides. The synthesis of these copolymers was confirmed by 1H NMR spectra and through cloud point measurement, the corresponding LCST was determined. Both copolymers were degraded by collagenase enzyme at 25 ° C and their 1H NMR spectra confirmed this process. Both copolymers were cleaved by collagenase, leading to an increase in solubility which yielded a higher LCST compared to before enzyme degradation. Future studies will focus on evaluating other peptides and also using other techniques such as Differential Scanning Microcalorimetry (DSC) to better observe the LCST behavior. Moreover, enzyme kinetics studies is also crucial to evaluate how fast the enzyme degrades each of the copolymers.

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2018-05

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Analog-to-Digital Converter Reliability Testing in Hostile Environments

Description

Analog to Digital Converters (ADCs) are a critical component in modern circuit applications. ADCs are used in virtually every application in which a digital circuit is interacting with data from the real world, ranging from commercial applications to crucial military

Analog to Digital Converters (ADCs) are a critical component in modern circuit applications. ADCs are used in virtually every application in which a digital circuit is interacting with data from the real world, ranging from commercial applications to crucial military and aerospace applications, and are especially important when interacting with sensors that observe environmental factors. Due to the critical nature of these converters, as well as the vast range of environments in which they are used, it is important that they accurately sample data regardless of environmental factors. These environmental factors range from input noise and power supply variations to temperature and radiation, and it is important to know how each may affect the accuracy of the resulting data when designing circuits that depend upon the data from these ADCs. These environmental factors are considered hostile environments, as they each generally have a negative effect on the operation of an ADC. This thesis seeks to investigate the effects of several of these hostile environmental variables on the performance of analog to digital converters. Three different analog to digital converters with similar specifications were selected and analyzed under common hostile environments. Data was collected on multiple copies of an ADC and averaged together to analyze the results using multiple characteristics of converter performance. Performance metrics were obtained across a range of frequencies, input noise, input signal offsets, power supply voltages, and temperatures. The obtained results showed a clear decrease in performance farther from a room temperature environment, but the results for several other environmental variables showed either no significant correlation or resulted in inconclusive data.

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2019-05

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Predicting Mechanical Failure of Vacuum Pumps Using Accelerometer Data

Description

The objective of this paper is to find and describe trends in the fast Fourier transformed accelerometer data that can be used to predict the mechanical failure of large vacuum pumps used in industrial settings, such as providing drinking water.

The objective of this paper is to find and describe trends in the fast Fourier transformed accelerometer data that can be used to predict the mechanical failure of large vacuum pumps used in industrial settings, such as providing drinking water. Using three-dimensional plots of the data, this paper suggests how a model can be developed to predict the mechanical failure of vacuum pumps.

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2019-05

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Around the Corner Imaging: Developing a Graphical User Interface

Description

This Creative Project was carried out in coordination with the capstone project, Around the Corner Imaging with Terahertz Waves. This capstone project deals with a system designed to implement Around the Corner, or Non Line-of-Sight (NLoS) Imaging. This document discusses

This Creative Project was carried out in coordination with the capstone project, Around the Corner Imaging with Terahertz Waves. This capstone project deals with a system designed to implement Around the Corner, or Non Line-of-Sight (NLoS) Imaging. This document discusses the creation of a GUI using MATLAB to control the Terahertz Imaging system. The GUI was developed in response to a need for synchronization, ease of operation, easy parameter modification, and data management. Along the way, many design decisions were made ranging from choosing a software platform to determining how variables should be passed. These decisions and considerations are discussed in this document. The resulting GUI has measured up to the design criteria and will be able to be used by anyone wishing to use the Terahertz Imaging System for further research in the field of Around the Corner or NLoS Imaging.

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2019-05

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Dynamic Changes in Heart Rate and Cerebral Blood Flow During Acute Vagal Nerve Stimulation

Description

Vagal Nerve Stimulation (VNS) has been shown to be a promising therapeutic technique in treating many neurological diseases, including epilepsy, stroke, traumatic brain injury, and migraine headache. The mechanisms by which VNS acts, however, are not fully understood but may

Vagal Nerve Stimulation (VNS) has been shown to be a promising therapeutic technique in treating many neurological diseases, including epilepsy, stroke, traumatic brain injury, and migraine headache. The mechanisms by which VNS acts, however, are not fully understood but may involve changes in cerebral blood flow. The vagus nerve plays a significant role in the regulation of heart rate and cerebral blood flow that are altered during VNS. Here, we examined the effects of acute vagal nerve stimulation on both heart rate and cerebral blood flow. Laser Speckle Contrast Analysis (LASCA) was used to analyze the cerebral blood flow of male Long\u2014Evans rats. Results showed two distinct patterns of responses whereby animals either experienced a mild or severe decrease in heart rate during VNS. Further, animals that displayed mild heart rate decreases showed an increase in cerebral blood flow that persisted beyond VNS. Animals that displayed severe decreases showed a transient decrease in cerebral blood flow followed by an increase that was greater than that observed in mild animals but progressively decreased after VNS. The results suggest two distinct patterns of changes in both heart rate and cerebral blood flow that may be related to the intensity of VNS.

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2018-05

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Image Analysis for Registration, Segmentation, and Intensity Measurement of 2-Photon Microscope Images using MATLAB

Description

Traumatic brain injury (TBI) is a major concern in public health due to its prevalence and effect. Every year, about 1.7 million TBIs are reported [7]. According to the According to the Centers for Disease Control and Prevention (CDC), 5.5%

Traumatic brain injury (TBI) is a major concern in public health due to its prevalence and effect. Every year, about 1.7 million TBIs are reported [7]. According to the According to the Centers for Disease Control and Prevention (CDC), 5.5% of all emergency department visits, hospitalizations, and deaths from 2002 to 2006 are due to TBI [8]. The brain's natural defense, the Blood Brain Barrier (BBB), prevents the entry of most substances into the brain through the blood stream, including medicines administered to treat TBI [11]. TBI may cause the breakdown of the BBB, and may result in increased permeability, providing an opportunity for NPs to enter the brain [3,4]. Dr. Stabenfeldt's lab has previously established that intravenously injected nanoparticles (NP) will accumulate near the injury site after focal brain injury [4]. The current project focuses on confirmation of the accumulation or extravasation of NPs after brain injury using 2-photon microscopy. Specifically, the project used controlled cortical impact injury induced mice models that were intravenously injected with 40nm NPs post-injury. The MATLAB code seeks to analyze the brain images through registration, segmentation, and intensity measurement and evaluate if fluorescent NPs will accumulate in the extravascular tissue of injured mice models. The code was developed with 2D bicubic interpolation, subpixel image registration, drawn dimension segmentation and fixed dimension segmentation, and dynamic image analysis. A statistical difference was found between the extravascular tissue of injured and uninjured mouse models. This statistical difference proves that the NPs do extravasate through the permeable cranial blood vessels in injured cranial tissue.

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2018-05

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Optical Feedback Mechanism for Detecting Cerebrospinal Fluid Leaks During Spinal Surgery

Description

For my honors thesis, I developed a proof of concept alpha prototype of a biomedical device for detection of cerebrospinal fluid leaks during spinal surgery. Cerebrospinal fluid leaks are a consequence of tears in the dura mater of the spinal

For my honors thesis, I developed a proof of concept alpha prototype of a biomedical device for detection of cerebrospinal fluid leaks during spinal surgery. Cerebrospinal fluid leaks are a consequence of tears in the dura mater of the spinal cord and can result in potentially life-threatening conditions and are overall a large burden not only on the patient but upon the clinical teams managing the patient postoperatively. What I created was an optical sensor that I programmed to be sensitive to detecting green wavelength light. The device would ideally be attached to surgical drain tubing and used in conjunction with fluorescein (a green fluorescent dye) infused lumbar punctures into the spinal canal of patients. As the dye circulates through the spinal cord, any tears in the dura mater would cause the fluorescein to leak out with cerebrospinal fluid into the incision site. This fluid may then be collected by the surgical drain where the sensor may detect the fluorescein, triggering a buzzer response that would notify the patient or the surgeons of an ongoing leak that requires repair. The time I spent on my thesis involved sensor validation to ensure it could differentiate between colors, testing the sensor's color sensitivity by performing a fluorescein aliquot, and running proof of concept testing that could show the sensor can detect fluorescein drain tubing and provide an adequate response. The sensor was able to differentiate between varying concentrations of fluorescein in solution and provided exceptional results in its proof-of-concept testing. Next steps will be to re-run the sensor validation study with different dyes as well as consolidating the device's electrical hardware onto a single circuit board as development of beta and gamma prototypes move forward.

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2018-05

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Automatic Recording of Children's Activity Within a Classroom: A Study of Levy Flights

Description

The diagnosis for an attention deficit/hyperactivity disorder (ADHD) in children is heavily based on teacher or parent opinion, and not on scientific evidence. This causes children to be wrongly diagnosed with a disorder and be prescribed medicine that they do

The diagnosis for an attention deficit/hyperactivity disorder (ADHD) in children is heavily based on teacher or parent opinion, and not on scientific evidence. This causes children to be wrongly diagnosed with a disorder and be prescribed medicine that they do not need to be taking. This paper discusses a project that was completed for the Child Study Lab (CSL) preschool at Arizona State University (ASU), in which children’s activity within a classroom was automatically recorded using ultra-wideband technology. This project’s goal was to gather location data on the children in the CSL and analyze and assess the collected data for any patterns of behavior. The hope was that if a child’s data displayed a pattern that strayed from the norm, that this analysis could pose as a more objective way to indicate that a child may have an attention deficit problem. Fractal Dimensions and Levy Flights were researched and applied to the data analysis portion of this project.

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2020-05

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Optimization of Front Contact Design on Nickel-Plated Si Solar Cells

Description

As global population and demand for electrical power increase, humanity is faced with the growing challenge of harnessing and distributing enough energy to sustain the developing world. Currently, fossil fuels (coal
atural gas) are our main sources of electricity. However,

As global population and demand for electrical power increase, humanity is faced with the growing challenge of harnessing and distributing enough energy to sustain the developing world. Currently, fossil fuels (coal
atural gas) are our main sources of electricity. However, their cost is increasing, they are nonrenewable, and they are very harmful to the environment. Thus, capacity expansion in the renewable energy sector must be realized to offset higher energy demand and reduce dependence on fossil fuels. Solar energy represents a practical solution, as installed global solar capacity has been increasing exponentially over the past 2 decades. However, even with government incentives, solar energy price ($/kWh) continues to be highly dependent on political climate and raw material (silicon and silver) cost. To realistically and cost effectively meet the projected expansions within the solar industry, silver must be replaced with less costly and more abundant metals (such as copper) in the front-grid metallization process of photovoltaic cells. Copper, while offering both higher achievable efficiencies and a raw material cost nearly 100 times cheaper than silver, has inherent disadvantages. Specifically, copper diffuses rapidly into the silicon substrate, requires more complex and error-prone processing steps, and tends to have less adhesive strength, reducing panel robustness. In this study, nickel deposition via sputtering was analyzed, as well as overall potential of nickel as a seed layer for copper plating, which also provides a barrier layer to copper diffusion in silicon. Thermally-formed nickel silicide also reduces contact resistivity, increasing cell efficiency. It was found that at 400 \u00B0C, ideal nickel silicide formation occurred. By computer modeling, contact resistivity was found to have a significant impact on cell efficiency (up to 1.8%). Finally, sputtering proved useful to analyze nickel silicide formation, but costs and time requirements prevent it from being a practical industrial-scale metallization method.

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2017-05