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Show more3D Printing, or additive manufacturing, is a novel approach to manufacturing simple and complex structures. 3D printing uses digital models and g-code to build these parts layer by layer. This method can allow for more freedom of part design with regard to complexity of shape, and can reduce material waste compared to other manufacturing methods. This project explores the 3D printability of common caulking materials, cements, adhesives, and other pastes. These materials are low-cost and present high printability. Experiments are underway to determine the thermomechanical properties of these 3D printed materials and the effects of nanomaterial additives in low loading (1% by weight or less) in these materials. The additives being tested are carbon nanotubes, graphene oxide, and silica nanoparticles. They have the potential to improve the thermal and electrical conductivity of these materials as well as the thermomechanical properties. Aging studies using high temperature, pressure and moisture are being utilized to test the long term viability of these materials as well.
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Show moreAs COVID-19 continues to spread in our society, wearing face masks have become an integral part of daily life. For users with disabilities, specifically those with hearing impairments, the utilization of face masks creates additional problems. The obstruction of facial and visual expressions from mask wearing poses an increased difficulty in communicating with individuals when lip reading is not accessible; additionally, the elastic straps that hold the mask in place can become entangled or dislodge hearing aids, creating more discomfort for the users. Further, blocking a majority of the face from view makes it harder to see critical vital and life-threatening signs of potential seizures and strokes. While there are some current solutions, many are highly specific, while others are expensive and inefficient. Therefore, this project aims to develop a mask that can alleviate these issues at a more accessible, sustainable, and cost level. The physical and chemical properties of various materials, including hydrophobicity, wettability, and skin biocompatibility, will be evaluated to validate the design. We propose an improved 3-layer mask system with a small clear window through each layer to promote visualization of the mouth and support proper filtration of air flow. A nose pinch will be incorporated to diminish fogging of glasses, as well as a redesigned head strap that repositions the straps away from the ears will prevent the accidental displacement of hearing aids.
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Show moreDespite the popularity, we noticed that it is rather hard to verify a NLP/text-mining like stock prediction model's performance due to the amount of "groundwork" needed. It is very typical a researcher will have to gather the plain text data, the company info, the stock market data, and categorize them in a way that is communicable with each other and the model; then the researcher will need to build a virtual trading platform that keeps track of all the trading signals generated by the model, log the activities in a certain way, then do some kinds of visualization for evaluations. To implement all these steps from ground up, it is required for a researcher to have certain level of proficiency on skills which are, from a research stand-point, fairly deviated from the nature of the NLP/text-mining model itself (like scraping a website and understanding the fundamental mechanism of trading in stock market). Thus, we like to build a set of lightweight tools that may automate such process to a certain degree.
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Show moreSimulation education for medical and health professional training bridges classroom learning and training in a clinical environment. Its use has been increasing over the past two decades. Guidance to avoid in-person contact due to SARS-CoV-2 has further increased demand. Pure-tone audiometry is part of an audiometric test battery used to evaluate the auditory system. At Case Western Reserve University, students typically learn to conduct audiometry in COSI 370: Introduction to Audiology. Under current pandemic circumstances, students are unable to gain in-person experience using standard hardware (an audiometer and calibrated headphones). AvatarAudiometer solves this problem via an interactive online tool that mimics a real audiometer and simulates patient responses. The system consists of a simulation of pure-tone audiometry and a tool for graphing results on a standard audiogram interface. AvatarAudiometer allows students to measure unmasked air- and bone-conduction thresholds for each ear at octave and interoctave frequencies, 250-8000 Hz. The virtual patients' responses to tones are based on their individual hearing level thresholds. Because real humans are inconsistent in their responding, AvatarAudiometer patients differ from one another in their frequency of false positive/negative responses, range of reaction times, and duration of holding down the virtual response button. Two sources of patient audiometric profiles are included: 1) curated audiograms simulating specific types, configurations, and severities of hearing loss, along with a description of each virtual patient’s case history, and 2) a sample of 5470 audiograms representative of the United States’ population by age and sex selected from the CDC’s NHANES database. AvatarAudiometer includes a tutorial that demonstrates functions and settings of a standard audiometer. Students can complete numerous pure-tone audiometric exams and screen large cohorts of virtual patients to simulate a hearing-screening protocol. After testing is complete, an interface for plotting, editing, and downloading corresponding pure-tone audiometric results on an audiogram is shown. A professor may have students self-grade their audiograms by comparing the student-measured audiograms with those of the patient's "true" simulated pure-tone thresholds.
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Show moreThe diet of zoo-housed animals has significant implications to many aspects of each species’ health and survival. A recent study revealed the diet of free-ranging Matschie’s tree kangaroos (Dendrolagus matschiei) to be mostly browse-focused, including plants like leaves, ferns, and orchids. Prior to those findings, zoo-housed tree kangaroos were fed diets, mostly biscuit-based, that differ vastly from that of free-ranging tree kangaroos possibly contributing to widespread issues within zoos concerning obesity and low reproductive success. The Cleveland Metroparks Zoo (CMZ) houses two Matschie’s tree kangaroos which, in 2019, underwent a significant diet change from a more traditional, baseline, biscuit-heavy diet to one that is more leaf or ‘browse’-heavy to better reflect that of free-ranging tree kangaroos. Therefore, we are currently investigating how the behavior of zoo-housed tree kangaroos change after this diet shift. Baseline behavioral data was recorded at CMZ from December 2017 to November 2018 on the female tree kangaroo prior to implementing the new diet and behavioral data is currently being collected on the same female as well as the male tree kangaroo housed at CMZ after the new diet. Behavioral observations were made instantaneously at thirty second intervals for a period of twenty minutes using ZooMonitor from video recordings captured with the Annke camera system. Using a G-test, our preliminary results show that the female tree kangaroo’s activity budget differed significantly between the baseline and browse-heavy periods (G=446.9 ; p <0.001 ). With these results, we found that she doubled her time spent feeding during the browse-heavy period, with 8.0% of her time spent feeding during the baseline and 16.0% of her time spent feeding during the browse-heavy period. In addition, we found that the male tree kangaroo spent 11.4% of his time feeding during the browse-heavy period. These results suggest that a transition to a browse-heavy diet to better reflect free-ranging tree kangaroo diets can increase the time spent engaging in natural feeding behaviors for zoo-housed tree kangaroos. Future parts of this study will examine how the diet shift contributes to tree kangaroo energy expenditure, nutrient intake patterns, and reproductive endocrinology.
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Show moreOnline education has been prevalent for years, but with the spread of the Covid-19, it became the most viable option for students all over the world. Out of these students, an estimated 15-20% of them show signs of what the Fifth Edition of the Diagnostic and Statistical Manual of Mental Disorders describes as Specific Learning Disorder (SLD). Students with SLD experience difficulties with learning and using academic skills such as reading, writing, and mathematics. These difficulties are independent of intelligence. Over the past two decades, SLD has also been referred to as dyslexia or a learning disability. While adapting to online instruction could prove difficult for students with SLD, it is also an opportunity to provide them with a more individualized and flexible education. Research about online learning and SLD from before the pandemic led to the identification of best practices for instructing students with SLD during, and possibly after, the pandemic. A comprehensive literature review was conducted to determine whether making accommodations such as asynchronous learning materials, multimedia instruction, and text reading affordances available would lead to an online learning environment that would be advantageous for students with SLD. Research indicates that asynchronous learning, multimedia instruction, and text reading affordances can lead to be better learning for students with SLD. Asynchronous learning materials are materials, such as video recordings of lectures, that students can access outside of designated class times. Multimedia instruction involves presenting information in multiple formats such as images and audio, as opposed to solely text-based learning. Affordances such as adhering to certain recommended fonts and styles of writing can also make text more accessible to students with SLD. None of these supplements to instruction have proved universally helpful to students with SLD. Therefore, it is best to let the students to decide which accommodations are useful and when. Online learning presents a unique opportunity to make these accommodations available and allow students to pick and choose which of these accommodations best assist them.
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Show moreThe incurable and devastating disease of age-related hearing loss (ARHL) affects a majority of the elderly worldwide. As humans age, their cells of the inner ear, which are responsible for hearing, undergo degenerative aging, as well as apoptosis (programmed cell death). Scientists believe that ARHL may be associated with specific cell types of the inner ear known to be high in mitochondrial concentration. These sensorineural tissues as well as the specific neurons, namely hair cells, spiral ganglion neurons, and cells of stria vascularis, are susceptible to irreversible cellular damage. A decline of mitochondrial function is common in various age-dependent neurodegenerative diseases. Mitochondrial health is tightly regulated by Ca2+signals, which plays an important role in ARHL. Calcium and other cations enters via mechanotransduction channels when a sound from the outside environment comes in the inner ear that cause the hair cell bundles to deflect to one side with sound frequencies. Thus, the goal of this study was to reveal the intrinsic mechanisms that relate to energy metabolism and cellular calcium balance genes expression levels in the mammalian inner ear from early development. Changes in expression of energy metabolism genes in the inner ear cells were examined in mouse models, comparing these gene expression profiles in mice ranging from embryonic day 16 to adult age of up to 4 months. Mouse models are widely used to study mammalian hearing and comprehensive databases are available. Here, databases were used to compare with preliminary data that was obtained in Dr. Ruben Stepanyan’s laboratory that had indicated the expression of mitochondrial metabolism genes can alter with age, possible affecting hearing. Once this data was obtained, it was compared on a spreadsheet and graphed using Excel. The following graphs of expression levels were made: fluorescence activated cell sorting (FACS) of all genes studied, spiral and vestibular ganglion neurons, inner and outer hair cells, and fluorescence activated cell sorting (FACS) of all the individual genes. In doing so, we were able to identify mitochondrial metabolism and cellular calcium balance-related genes that can undergo changes in expression levels in the mammalian inner ear, thus providing their importance in hearing.
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Show moreMeiosis is an important mechanism that generates genetic variation for sexually reproducing organisms through recombination. In order for an organism to successfully propagate its genetic material from one generation to the next, its genome must be properly delivered as gametes. Meiotic crossing over of DNA ensures proper homolog segregation by repairing programmed double-stranded breaks. Meiotic defects caused by chromosome structural variants are detrimental to reproduction. During the interchromosomal effect, heterozygous inversions suppress crossing over between affected chromosomes while increasing crossing over between normal chromosome pairs. These defects in chromosomal dynamics trigger the pachytene checkpoint, leading to a delay in prophase progression. It has been suggested that this delay in prophase causes the interchromosomal effect on recombination. However, whether the interchromosomal effect on crossing over is caused directly by defects in chromosome dynamics or indirectly by the delay in prophase remains unclear. We are distinguishing between these two hypotheses by investigating the distributions and frequencies of crossovers in Drosophila mutants when prophase is extended by utilizing maelstrom mutants that trigger the pachytene checkpoint independently of chromosome defects. We are analyzing the changes in crossover distribution and frequencies in these mutants using recessive markers on unaffected chromosome. We are also collecting confocal imaging data of the mutants’ germarium to visualize the effects of maelstrom mutations on meiosis. Our data will provide insights into the mechanisms of the interchromosomal effect and reveal whether or not the interchromosomal effect is directly mediated by a delay in pachytene or, alternatively, mediated by disrupted crossover control mechanisms.
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Show moreIntramolecular BO-chelated azadipyrromethenes are promising organic semiconductors. Here, we evaluated the electron and hole mobility of a series of BO-chelated azadipyrromethenes using the Space Charge Limited Current(SCLC) method. In order to determine the mobility of the material, Mott Gurney’s law was applied using the film thickness and slope of the J1/2 versus voltage plot in the SCLC graph. The best electron mobility observed for BO-chelated materials is 4.64×10-6 cm2V-1s-1 and the best hole mobility is 7.38×10-4 cm2V-1s-1. These results suggest that BO-chelated materials are promising p-type semiconductors for electronic applications.
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Show moreMicrobial communities play a key role in shaping many diverse ecosystems through their biogeochemical contributions. These communities comprise not only bacteria and archaea but also their viruses, whose reproduction profoundly affects host cell biology. While many bacterial species have been well characterized, the challenges of isolation and sequencing have hampered the study of environmental viruses such as bacteriophages. The model organism Azotobacter vinelandii is a common nitrogen-fixing soil bacterium. To our knowledge, no Azotobacter phages currently exist in culture. However, modern bioinformatic and database approaches can be used to identify the metagenomic sequences that may derive from bacteriophages that infect Azotobacter. We have developed a pipeline that scans metagenomic samples from the IMG JGI database to identify phage sequences whose abundance co-varies with Azotobacter vinelandii abundance. The viral sequences identified can be grouped into clusters, and the resulting clusters can then be analyzed for auxiliary metabolic genes (AMGs). These candidate sequences may then be used to guide phage isolation strategies and predict phage ecological impact.
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Show moreHyperthermia is a condition when the body’s heat-regulation system is overwhelmed and a person’s core body temperature (CBT) is above 100.4°F (38°C). This is a major risk among athletes and occupational workers in the military, construction, manufacturing, and emergency response who engage in intense physical activity. Currently the gold standard to measure CBT is through a rectal thermometer. While rectal thermometers are accurate, they are quite invasive and do not provide a way for continuous monitoring. Other skin and oral thermometers which are considered noninvasive are not accurate because they only measure surface temperature and are easily influenced by other artifacts such as motion or the external environment. There is therefore a need for a wearable device that can continuously and noninvasively monitor CBT while also being as accurate as the rectal thermometer. This project details the creation of a continuous monitoring system that uses heart rate to accurately predict CBT through a chest belt placed at the upper thorax. Heart rate signal is more stable than temperature sensors and through a correctional algorithm the estimated core body temperature can be measured and used to warn of possible hypothermia. The device will also relay information to an external device that can notify coaches or other members of dangerously high CBT, so they can ensure the user stops physical activity. Overall, this noninvasive continuous monitoring system can be used in a variety of applications and will help expand the wearable device market and prevent temperature related illnesses such as hypothermia.
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Show moreAs a result of recent climate change, many species are rapidly altering their geographic ranges, in a phenomenon known as range shifting. In general, the shifts tend to be geographically poleward or upslope, but there is a lot of variation in the magnitude or direction of contemporary range shifts. Theory suggests that specialization might constrain range shift responses. In this experiment, we examined the relationship between the magnitude and direction of range shift responses and degree of diet specialization of Ohio butterfly larvae. We used a long-term monitoring dataset of butterfly range dynamics to test this relationship. Surprisingly, we did not find any association between the range shift responses and the dietary specialization, after accounting for the shared evolutionary history among species. In future work, different methods of quantifying diet breadth may reveal an association. Further research in the same area will be focused on finding other traits that may be predictive of range shifts.
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Show moreGamification is the application of game elements such as badges, points, leaderboards, … to a nongame area of activity. The corporate setting has burgeoned in incorporating gamification into areas such as recruitment, training, and marketing with established corporations reported to have success in gamifying their business. However, the current literature report mixed results on whether gamified training could lead to an improvement in performance. This article attempts to summarize the current state of gamified training and its effectiveness by conducting a meta-analysis on the subject. Although an effect size was calculated, the result was unreliable due to a lack of papers meeting our criteria of inclusion for the meta-analysis. This implied a lack of rigorous empirical research methodology on this topic. As gamification becomes more prevalent in training settings, this paper hopes to provide recommendations for future researches in examining the effectiveness of this novel training model.
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Show moreThe focus of this research was to determine a milling procedure to help facilitate the Cr2Nb transformation. The metric to evaluate a facilitated phase transformation was a reduction in endothermic onset temperature during Differential Scanning Calorimetry (DSC). The transformation of the Cr+Nb powder to Cr2Nb alloy is diffusion dependent, therefore by creating more intimate contact the elements will be closer together. A reduction in spatial distance for a diffusion-based reaction will lead to a reduction in total time for the reaction to complete. The design of a multi-stage milling process allows the refinement of the powder particle size so that diffusion can more easily occur at a lower temperature. The effectiveness in powder size reduction was tested for two bearing sizes to determine the required milling time for each stage. It was determined that dry milling elemental Cr powder for 5 minutes with 4.88mm bearings and then wet milling for 3 minutes with 2.47mm bearings produced a size distribution with a D90 less than 25𝜇m. After determining this 2-step milling procedure, a mixture of Cr+Nb powder was milled with the 2-step process and compared with Cr+Nb powder that had been milled with a 1-step process. X-Ray Diffraction (XRD) was done on the mixtures before DSC and the results showed the presence of elemental Cr and Nb. These two mixtures were then exposed to a controlled heating rate of 20 degrees C per minute up to 1400C in a Netzsch Pegasus 404 F1 DSC and then cooled. Post-DSC, the XRD results showed a significant increase in the presence of Cr2Nb alloy. Therefore, the endothermic reaction visible in the DSC results must have been the phase transformation from elemental Cr and Nb to Cr2Nb alloy. In comparing the 1-step and 2-step milling processes, the DSC results show that the transition temperature of the Cr+Nb powder was reduced from 1229C to 1089C when the milling was changed from 1-step to 2-step. Future research will investigate the effects of such milling on the in-situ formation of Cr2Nbduring additive manufacturing processes.
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Show moreThe process of dating has changed significantly in the past three decades. This has left people, especially young adults, confused, and unsure of what has changed or how to act. This literature review aims to explain the factors that have caused the “dating game” to change in regards to perceptions of sexual attraction, mainly the shift of personality preferences away from evolutionary characteristics, the decrease in conformity in today’s society, and the recent rise of online dating. A brief overview of the timeless evolutionary factors, which have affected attraction for centuries, will set the stage for how these factors are no longer as essential towards sexual attraction in the current time. A thorough comparison of attractive personality preferences from before 1990 and after 1990 will highlight the change that has occurred. Using the same before and after method, a decrease in conformity in today’s society will also be demonstrated regarding preferred personality preferences. Furthermore, the effect of online dating becoming more popular will be explained in its relevance to the change in perceptions of sexual attraction. Finally, the significance of these findings will be analyzed, and advice will be offered to the current generation concerning how to proceed in these perilous times.
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Show morePlasma water treatment (PWT) is an emerging water treatment technology that utilizes electrical discharges in gases to degrade aqueous contaminants. Prior work has demonstrated that PWT is capable of degrading perfluorooctanoic acid, a widespread contaminant that is unable to be degraded by denitrification or UV processes that wastewater facilities currently employ. In addition, unlike other approaches, PWT forms energetic species directly from water, eliminating the need for additional chemicals or catalysts. However, internal mechanisms within PWT treatment process, such as the production of different radical species are not well understood. Characterization of the species and their role in degradation is necessary to optimize the process. A challenge is that PWTs generate ultraviolet radiation, electrons, ions, and other non-equilibrium species, and these species are extremely short-lived and recombine or react within nanoseconds of formation. As a result, these species cannot be detected using analytical chemical techniques alone. In this work, we generated an argon-based, non-equilibrium plasma at the gas-liquid interface of aqueous solutions. Using PFOA as a model contaminant at environmentally-relevant concentrations from 0.02 mM to 1 mM, we demonstrate degradation with a maximum of 29% after 2 hours of treatment. To understand the degradation mechanism, we applied a chemical probe, terephthalic acid (TPA), which can specifically react with hydroxyl radicals (OH) and form a fluorescent compound, 2-hydroxyterephthalate (HTPA), that can be optically detected. While we observed the formation of OH, as the exposure to the plasma increased from 10 minutes to 4 hours, the intensity of the fluorescent peak was found to rapidly decrease. Using a control experiment, we show that the plasma is capable of degrading HTPA. These results indicate that chemical probes and their products are susceptible to species produced by the plasma which can compromise this technique. In the future, stable chemical probes or process conditions which avoid their degradation are required.
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Show moreTitanium dioxide nanoparticles (TiO2 NPs) are non-toxic and biocompatible materials that are used for a wide range of applications such as pigments, sunscreens, cosmetics, and food colorings. TiO2 possesses a large band gap (3.2 eV) which, by heteroatom doping or by molten salt/hydrogen assisted reduction, can be narrowed to allow for activity within the visible light spectrum making them optimal candidates for use in bacterial biofilm eradication. Nitrogen-doped and reduced TiO2 NPs have been explored in this study due to their narrowed band gap. The narrowed band gap allows for the formation of excitons upon the absorption of light within the visible range. The excited charge carriers are transported to the NP surface where they react to form reactive oxygen species (ROS). These ROS interact with microbial membranes and cause cell wall damage, resulting in cell death. A study by the Samia Lab exploited and improved existing synthetic approaches and post-synthetic processing techniques to produce TiO2 NPs with enhanced visible light photoactivity for anti-biofilm applications using the mode of action described above. The most effective disruption of S. aureus biofilm was observed with the use of treated Nitrogen-doped TiO2 (N-TiO2), which included Magnesium-reduced (Mg-N-TiO2) and Hydrogen annealed Mg-N-TiO2 NPs (H-Mg-N-TiO2 NPs), under visible irradiation over 30 minutes. Future studies hope to expand upon these results with the optimization of reduced N-TiO2 concentration, light excitation intensity, and duration of treatment for a variety of bacterial biofilms.
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Show moreThis project involves the creation of a nighttime wearable device that can measure heart rate, blood oxygen saturation, temperature, motion, and skin resistivity using sensors placed on the upper and lower arm. Incorporating a wide variety of sensors allows for detection of focal and generalized epilepsy. These sensors will be used to collect data to wirelessly (via Bluetooth) transmit to a separate base station for processing to determine if a seizure has occurred. If a seizure is detected for a specified period of time, the base station can call (via cellular communications) for medical aid to prevent harm to users. Once this device is validated, the technology will help users track seizures better and grant peace of mind if a seizure were to occur.
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Show moreThe installation of a widespread readily available power system in the United States has been one of the number one engineering achievements of the 20th century. Now that a strong structure is in place to supply distribution electrification across the country, the next step is the modernization of these systems. Many distribution systems have not been modernized due to high costs associated with changes to the system. Modernization in the 21st century revolves around a high demand for clean energy as well as real time voltage/power flow analysis of these systems. In this project we will provide simulated models of distribution systems to show the potential effects of modernization techniques on the system before substantial investments are made. These simulations will be performed using Matlab Simulink in order to utilize the block diagram simplification layout. The simulations will demonstrate the modernization techniques of implementation of a wind generation source as well as a representative smart metering system to communicate voltage information. These techniques will be applied on two distribution feeder designs. The first design is a modification of the IEEE 13 node test feeder, chosen for its common features of shunt capacitors, overhead and underground lines. The second simulation design is a portion of Case Western’s campus running from the medical center company substation control house to the load of the Millis Science Center basement vault, representing an in use system. Both systems will receive the modernization techniques of wind generation and metering systems. Through this project shareholders can review such effects on the system before choosing to invest.
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Show moreSudden Unexpected Postnatal Collapse (SUPC) is a rare but serious condition defined as the positional occlusion of the airway in term and late preterm infants, and can lead to hypoxia, bradycardia, and unresponsiveness. If SUPC occurs, infants may require cardiopulmonary resuscitation or intensive care with mechanical ventilation, potentially resulting in encephalopathy or death. Neonates are most at risk for SUPC in their first two hours of life, and they remain at risk for seven days. The risk of SUPC is often associated with Skin-to-Skin Contact (SSC), a practice which is encouraged in order to promote emotional bonding between the infant and the caregiver (especially the mother), sustain life, and provide tangible physical health benefits. In order to assist with the detection and management of SUPC, there is a clinical need for a convenient, medically accurate, and affordable wireless device that monitors the biosignals of neonatal infants.
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