TTU Published Journals @ Volpe Library
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*WINNER* Investigation of the thermal properties of various short carbon fiber reinforced polymers in Fused Filament Fabrication process
No full textA considerable amount of literature has been published on the thermal properties of the additively manufactured polymers. However, there has been no study focused on the effect of the reinforced fiber in various matrix materials to measure the thermal properties of such additively manufactured parts. The aim of this research is to explore the influence of various matrix materials, numerically and experimentally, on the thermal conductivity, thermal strain and degree of healing in matrix materials of PETG, PC/PBT, ABS and Nylon. The anisotropic behavior of the composites is also evaluated by changing the build direction. This work also attempts to simulate the temperature evolution in the printed materials. In order to do this, 3D implicit finite difference method is constructed using element activation method. The results obtained are important in reporting the relationship between short carbon fibers and different polymers. Our research group has reported valuable findings on continuous fiber reinforced additive manufacturing processes. The current findings of our group for the thermal properties of short carbon fiber reinforced filaments performed in this study will be benchmarked to differentiate the pros and cons of both technologies
*WINNER* AI Based Optimization of Solid State Transformer Core for Modern Electric Vehicles Using Multi-Objective Genetic Algorithm
No full textSolid-state transformers are increasingly becoming a desirable alternative to traditional low frequency transformers due to their compact size and high efficiency, particularly in the field of Electric Vehicles (EV), which has seen rapid growth in recent years. This research offers a multi-objective AI-based high-frequency transformer (HFT) design optimization for solid-state transformer (SST) applications. As the key component of the SST, the optimization of the HFT design parameters is crucial for achieving high efficiency and power density, independent of its topology. The HFT is designed using a multi-objective Non-dominated Sorting optimization technique that reduces core volume (maximizing power density), total transformer losses, and overall cost from the set multiple Pareto-optimal solutions (POS). An 750kHz, 10kW HFT of different high permeability core materials is explored as a case study and the POS are presented. The findings show how the various design variables affect the goal functions. The results further show that the size, efficiency, and cost of the HFT may be efficiently optimized by carefully selecting design variables using the suggested method. A large number of the Pareto-Optimal solutions demonstrate that in the HFT design for SST applications, an efficiency of above 97% can be attained
Role of the Device Inclination on the Synthesis of Nanocomposite Gels
Get PDFHydrogels as nanocomposite materials have achieved significant improvement in the field of bio-separation. Combining hydrogels with nanoparticles significantly enhanced the efficiency and selectivity of the separation process. Moreover, adding nanofillers to hydrogels significantly improved the physical, thermal, and mechanical properties of the nanocomposite hydrogel in comparison with "regular" ones. Previously, Sodium Dodecyl Sulfate (SDS)-micelles have been added to polyacrylamide gel, as a nanocomposite template, used in protein gel electrophoresis for separating proteins with polyacrylamide gel electrophoresis (SDS-PAGE) which is a widely used technique. In a recent exploratory study, an improved protein separation by electrophoresis was achieved by incorporating SDS micelles within polyacrylamide gel in varying concentrations. The SDS micelles were used to alter the internal porosity of polyacrylamide gels in order to achieve better resolution of the protein's separation from the mixture. Therefore, understanding the effect of polymerization conditions on hydrogel structural properties is very important. The goal of this study is to investigate the role of the polymerization angle of gel casting system on the distribution of the nanoparticles within polyacrylamide gel. Preliminary results of this project will show the influence of device inclination through gelation process on the uniformity and the performance of the nanocomposite hydrogel
*WINNER* The Relationship of Adverse Childhood Experiences, Protective and Compensatory Experiences and Children's Flourishing
No full textWhile the widespread negative impacts of Adverse Childhood Experiences (ACEs) are well researched, information regarding Protective and Compensatory Experiences (PACEs), their relationship to ACEs, and children's ability to flourish is less understood. The specific categories of adversity examined in this study include: hard to financially cover basics; parents separated or divorced; parent died; parent served time in jail; witnessed or experienced physical abuse; lived with anyone who was mentally ill; exposure to substance abuse; and treated or judged unfairly due to race/ethnicity. The categories of protective experiences examined in this study include unconditional love; having a best friend; volunteering; being a part of a group; having a mentor; living in a clean, safe home with enough food; getting an education; having a hobby; regular physical activity; and having rules and routines. Utilizing the 2019 National Survey of Children's Health data, this study explores the relationship between ACEs, PACEs and children's ability to flourish. This study also investigates the theory that PACEs could buffer the negative impacts of adversity by moderating the relationship between ACEs and children's ability to flourish. A better understanding of the relationship between ACEs, PACEs, and flourishing could lead to development of PACEs-related programming and further research regarding how communities can help children build resilience and potentially lessen the impacts of ACEs
Exploring the TAS-20
No full textThe Toronto Alexithymia Scale-Revised (TAS-20) is a frequently used questionnaire designed to evaluate the construct of alexithymia. The TAS-20 employs a three-factor model which includes difficulty identifying feeling (DIF), difficulty describing feeling (DDF), and externally oriented thinking (EOT). The purpose of this study is to compare and contrast the application of alternative factor models of the TAS-20 with the original three-factor. A confirmatory factor analysis was completed on a sample of college students enrolled in undergraduate psychology courses at a university located in the southeastern United States (n= 357; 63.1% male, age 18-57 years; M=19.40). Results from the CFA analysis and tests of dimensionality supported the original three-factor model (GFI .901; CFI .907; RMSEA, .058) as the best model fit. Concerns of convergent validity were noted within the subscale AVE analyses (DDF, 0.428; DIF, 0.500; and EOT, 0.141). Further analysis of the EOT scale revealed concerns regarding discriminant validity (AVE, 0.141; MSV, 0.134). Factor loadings were replicated for fifteen of the original items. This study's findings conclude the usage of the TAS-20 provides greater understanding of alexithymia and its constructs (subscales). The use of the TAS-20, specifically the consideration of the subscale scores, within clinical settings may provide clinicians with greater insight working with clients
Network Intrusion Detection and Attack Type Classification using Machine Learning
No full textIn handling vulnerabilities in computer networks, Network Intrusion Detection System (NIDs) plays a vital role. Complex and time-varying network packets are flowing between connected networks and a large portion of the network data may remain normal whereas there is small portion of attack data that can be mixed. There are many kinds of network attacks. To detect and classify various kinds of attack data in network packets, machine learning algorithms are very popular and inevitable to be applied. We intend to use the NSL-KDD Dataset which was published in 2001 as an improvement to the KDD Cup'99 dataset where there are 24 different attack types mixed with normal data in the training set. There are 41 features for each of the data in the network dataset. In this work, we use machine learning algorithms to classify both normal and attack data. While there are many classification techniques, our goal is to increase the typical accuracy in detection and classification of network intrusions. To demonstrate the effectiveness of our approach, we present the confusion matrix that demonstrates accuracy, and include a graphical representation of the clusters in order to better visualize the classification of different types of attacks
Synthesis of 5-fluoroisatin and 7-fluoroisatin Thiosemicarbazone Ligands
No full textIsatin thiosemicarbazones have been known for a long time to have biological properties such as in the production of anti-tuberculosis drugs. Recently they have been used in the synthesis of metal complexes. We have investigated the synthesis and characterization of the 5-fluoroisatin and 7-fluoroisatin thiosemicarbazones. This poster presents information on synthesis and NMR characterization of the ligands to form Pd(II) complexes
Thin-layer chromatography presumptive test kit to qualify Cannabis plant material
No full textThe United States 2018 Farm Bill separated Cannabis production into two categories: marijuana and hemp. Clandestine marijuana is defined by more than 0.3% tetrahydrocannabinol (THC), and hemp is anything lower than that THC permitter. Cannabinoids are only identifiable at a molecular level which has become a problem for different agencies as the current presumptive forensic test kits can only test the presence of Cannabis. Developing a new presumptive test kit that can differentiate marijuana and hemp on a molecular level is pertinent to solving this issue for law enforcement and farmers both. Using thin layer chromatography (TLC), the plant material matrix is separated, and the individual cannabinoids are visible to the user. A polyester backed TLC plate, a moderately polar mobile phase and extraction fluid, and a commercial water-soluble stain allows the kit to be used in rugged environments. Time and temperature studies were conducted to simulate the real-life conditions. The method used successfully differentiated the cannabinoids in seven lots of marijuana and fifteen lots of hemp by staining CBD as an orange color and THC as a red. The kit being rapid, cost efficient, and simple to operate creates an opportunity for any person to use it. The low cost is advantageous for rural law enforcement and farmers and furthers Tennessee Tech's Grand Challenge focusing on the development of rural areas
Anion Photoelectron Spectroscopy and Thermochemistry of Deprotonated Benzonitrile Isomers
Get PDFIn this study, the negative ion photoelectron spectra of ortho, meta and para deprotonated benzonitrile anionic (o-,m-,p-C6H4(CN)¯) isomers as well as the corresponding thermochemical values of the o-,m-,p-C6H5(CN) isomers are reported. Quantum mechanical calculations based on density functional theory (DFT) with 6-311++G** and the aug-cc-pVQZ basis sets show that the o-,m-,p-C6H4(CN)¯ have electron affinity (EA) values of 1.901, 1.778, and 1.789 eV respectively. The computed Franck-Condon factors obtained using the PESCAL program results in o-,m-,p-C6H4(CN) vibrational structures that have several dominant active vibrational modes: a ring breathing mode around 1600 cm-1, a ring deformation mode at 630 cm-1 and a low frequency butterfly mode at 160 cm-1. Deprotonation at the ortho position gives a calculated gas-phase acidity value of 1600 kJ/mol. The calculated value is in close agreement with the previously reported high-pressure mass spectrometry experimental value of 1603.0 ± 10.0 kJ/mol. The enthalpy of deprotonation of benzonitrile (?acidH298(C6H5CN)), the C-H bond dissociation energy (DH298(H-C6H4CN)), the ionization energy of Hydrogen (IP(H)) and the EAs of the o-,m-,p-C6H4(CN) radicals are related to each other through the negative ion thermochemical cycle:?acidH298(C6H5CN) = DH298(H-C6H4CN)+IP(H)-EA(C6H5CN). The EA values of the o-,m-,p-C6H4(CN) are therefore combined with the ?acidH298(C6H5CN) to obtain values for the C-H bond enthalpy of o-,m-,p-C6H5(CN) at 298K
Black Injustices in the Criminal Justice System
No full textAfrican Americans have been targeted, killed, and judged unruly in the United States by the police more often than white individuals (LaFraniere and Lehren, 2021). Thus, the problem is that the latest struggle for black lives is for society to recognize the humanity of African Americans and enable them to live freely, safely, and equally (Marilyn, 2021). Racist police behavior today is part of a deep legacy of racism in the United States, which often finds its extreme manifestations in law enforcement (Gabiner,2016). Black youth are 41% more likely to be victims of any police use of force than comparable White youth. Sadly, the patterns are similar when we predict stops in which officers pull their guns and are prepared to shoot. Black youth are over 50% more likely in similar stops to find themselves staring down the barrel of a gun than white youth (Rory, 2017). The discriminatory consequences of the war on drugs are clear. Three-quarters of those arrested for drug offenses are Black or Latino. In seven states, 80 to 90 percent of incarcerated drug offenders are Black. These differences cannot be explained by disproportionate drug use among African Americans; Studies show they don't use drugs more than any other group, and some studies have even found they use drugs less often than other groups (Butler, 2010). My main priority is to find ways to let African Americans be heard and to make it safer for them to live their lives