TTU Published Journals @ Volpe Library
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Developing Synthetic Materials for Percussion Instruments
Get PDFThere is a need for new, sustainable materials to make wooden percussion instruments. Many of the woods used in producing these instruments are exotic or endangered woods. Some companies have switched to fiber-reinforced (glass or carbon) plastics or polymers, but these instruments do not always have the desired sound. Without the necessary desired sound and an increasing need to replace wood, attention must be given to studying and experimenting with other materials. Research shows that the properties of different woods are critical when selecting which materials to use in which instruments. The Young’s Modulus, hardness, density, grain direction, and adaptability to moisture are the properties that determine the speed and color/tone of the sound of the instrument. Data was collected to determine what types of sounds and responses musicians favor in percussion instruments. With that in mind, analyzing the frequency response of different materials are key. Vibrational analysis of soundwaves using a vibrometer, to study the frequency difference between a reference laser and a beam testing a surface, was performed to quantify the difference in the sound of traditional wood instruments along-side synthetic material made instruments. Such information reveals the properties desired and responses that must be replicated when designing new synthetic materials for instrument making. Using the data collected, production of a sustainable prototype materials can begin
On Flow Visualization Experiments in a Massively Arrayed Microfluidic Production System
No full textThe pharmaceutical industry is challenged with continuous production of nanomedicines with high throughput. Well controlled production can be accomplished in a microfluidic channel, but scale-up to massively arrayed microfluidics remains problematic. In case of a fiber-embedded reactor where the fibers define the microfluidic channels, flow visualization can be used to understand the pattern and path that growing particles trace out as they develop. Flow visualization techniques might include commonly used methods such as optical, non-optical and indirect. These techniques are reviewed with critical comparison to the fiber film reactor constraints. With a better understanding of the flow pattern via flow visualization, new models can be developed to better simulate two phase flows, mixing and precipitation within the reactor with special attention to the development of a narrow particle size distribution of nanoparticles
UL-FGA: Expanding The Database
No full textFor years now, America has been in need of a new type of aggregate that is both lightweight and environmentally friendly, along with encompassing other properties desired by various projects. AeroAggregate, LLC has now released an ultra-lightweight foamed glass aggregate (UL-FGA) in North America that has a low unit weight, a high friction angle, and is highly permeable. The purpose of this research was to expand the current database on this aggregate. During this research, the usage of photogrammetry sieve analysis and one-dimensional compression were used to test the properties of UL-FGA. Since UL-FGA had the property to break into smaller pieces when sieved in a standard sieve shaker, a solution was needed to get grain size analysis properly. This led to the use of photogrammetry sieve analysis. The software used could then accurately estimate the particle size in volume compared to the particle diameter of UL-FGA. This method is still not as accurate as a standard sieve shaker, but it did solve to the solution of getting an estimate of the grain size analysis without rounding the edges of the UL-FGA sample. This research also used the process of one-dimensional tests to get data such as plots of stress vs strain. This research was concluded by comparing the past research to this updated research, which resulted in many similarities and differences that can be used to gain a broader understanding of this aggregate and possible future uses
Prediction of mechanical properties of short fiber reinforced composite fabricated by Fused Filament Fabrication (FFF) method using Machine Learning
Get PDFThe tremendous increase in the application of additive manufacturing (AM) has gained much attention in recent times due to its usability and capacity to ascribe improved mechanical properties on printed parts with no tooling. AM process with the use of FFF is becoming an integral fabrication method for producing the complex geometries and machine components with intricate parts. There is a corresponding increase in dataset derived from AM process which has ushered the use of highly computational models like machine learning (ML) and deep learning for analysis, prediction, classification, dimensional accuracy, and optimization of methods and printing properties of fabricated parts. This study explores the contribution of printing parameters, e.g., printing speed, layer height and infill density on mechanical properties of short carbon fiber samples produced using FFF technology. ML models will be used for classification of samples built with different print parameters, the models will analyze microstructural images captured under microscope as input dataset and make prediction and classification based on their microstructural attributes (bead shape). In this study, the computation ability of ML models will be used in the predictions for improved mechanical properties based off results of tensile tests conducted on FFF material samples with various printing parameters. The findings of this study provide evidence and insight that ML can be used to optimize printing performance and its applications
*WINNER* Experimental and numerical characterization of functionally graded materials fabricated by the fused filament fabrication process
No full textIn this research study, mechanical and numerical characterization of functionally graded materials (FGM) fabricated by the multi-material fused filament fabrication (FFF) process have been studied. Design and digital fabrication of tensile, flexural, and compression samples have been performed using the voxelization method. Test samples were mechanically tested, and the results showed that the strength and modulus of ABS material enhanced significantly with the addition of PC material into the ABS matrix. Since the interface of multi-material parts is crucial and needs substantial improvement, different interface patterns were designed and mechanically tested using the tensile test method. Tensile strength of gradient pattern yielded better results than other joint types such as interlock and direct interface. Analysis of variance was also applied to understand the process-property-structure relationships. Microstructural samples showed that there are periodic voids between adjacent beads and layers of FFF-made parts. Therefore, a numerical homogenization method has been applied to obtain a mesoscale material property using Ansys Material Designer before performing macroscale finite element implementation. The results of numerical methods showed less than 10% error with respect to the experimental test results. Overall, the FFF process with FGM could have potential applications in medical, structural, and automotive industries by locally varying material properties. This study presents a unique method of fabricating FGM structures with a low-cost manufacturing process
Thermal and mechanical interactions between utility scale PV plants and the atmospheric surface layer
Get PDFDo large-scale PV plants change the near-ground temperature and the mechanics of the surface layer? The literature is divided on this topic, with some studies claiming that photovoltaic power plants adversely affect the local environment, and some argue otherwise. Arguments have been made that PV plants decrease near-surface temperatures. One such argument states that solar panels convert solar power into electrical power, which is then transmitted away from the environment, thereby removing energy. Another supporting argument suggests that solar panels block the ground's direct view of the sun, decreasing the amount of solar radiation absorbed by the earth during the day and lowering ground temperatures. Others conclude that near-surface temperatures would increase in the presence of a PV plant. For instance, one study found that nighttime ground temperatures were on average 4⁰C larger at a PV plant than two nearby urban and desert environments. Computational fluid dynamics (CFD) can offer a better understanding of this problem. I am using CFD to develop a deeper understanding of PV plants' impact on heat and temperature fluxes, atmospheric structure and stability, and wind profiles. My research considers variations in PV plant sizes, tilts, and arrangements. I also investigate changes in the background canopies on which the PV plants are built. My research includes limited field data measurements, required to feed the thermal boundary conditions of my simulations to implement realistic time-dependent boundary conditions. With good field and CFD data, one can produce accurate models to understand interactions between PV plants and their surroundings
Struwwelpeter still has value for Modern Day society with Children's Eating Habits and Distractions from Life.
No full textIn Heinrich Hoffmann's Der Struwwelpeter, Hoffmann attempts at illustrating lessons to children. These lesson are on how to behave and avoid the development of terrible behaviors and habits. In two of the ten stories that are within Der Struwwelpeter, Hoffmann protrays the terrible conqueneces of being a picky eater, unhealthy eating habits, and not paying attention to the real world and being distracted. These lessons are still valuable for modern day children and parents. Espeically with the growing of modern day problems of child obesity, laziness, addiction to various media forms such as video games, movies, and social media. Also, comparing the methods of teaching and helping children to not develop these bad behaviors or habits with modern day parenting to parenting durning the nineteenth century
Comparing Der Struwwelpeter: English vs German
No full textDer Struwwelpeter is a culturally significant children’s book in Germany. Written by Dr. Heinrich Hoffman, a children’s psychologist, in 1845, the book warns young children of the dangers of cruelty and disobedience. While the book is intended for children, many of the illustrations are graphic depictions of the consequences of misbehavior. These stories often feature the great injury or death of several children. This has led many English scholars to label Der Struwwelpeter as barbaric and unfit for children. However, many German speakers reflect on the book fondly. This poster seeks to explore the difference in interpretation of Der Struwwelpeter between cultures
COVID-19 in a Global, Economic Perspective
No full textWhile the emergence of the Corona Virus in humans is considered a novelty, historically speaking, it has a precedent in the “Spanish Flu” and the worldwide pandemic it caused in 1918. This project seeks to understand what lessons the prior pandemic has for the current world, especially when it comes to the economy on a national and global scale. After providing the major historical details of the 1918 pandemic and its cultural impact, this project will focus on the differences in how each pandemic was handled, how they impacted the world’s GDP, and how some countries recovered economically faster than others. Ultimately, the 1918 pandemic has much to teach us about how humans and their institutions react to a global challenge like a pandemic
Cultural Variations of Cinderella
No full textFairy tales are popular and highly adaptable ways to convey life lessons in a way that is easy for one to consume. Different cultures throughout the ages heave produced their own unique versions of the same story. Our poster will explore three interpretations of Cinderella as told in Germany, Ireland, and Russia. These stories are Aschenputtel, Billy Beg and the Bull, and Vasilia the Brave, respectively. We will explore how these different settings influenced the variances in the stories, as well as how each story conveys overarching lessons to those that read them. Lessons that will be expanded upon include not letting others control your life, efforts are rewarded, and benevolence in all situations