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The Silent Forest
No full textThis document details our process in creating an audio game, which is a game that consists entirely of audio, with minimal visual components. The goal of this project was to create an experience for the player that is immersive, engaging, and complete, while using audio as the primary form of communication with the player. In this paper we will describe and discuss the complete development process, encompassing our research, production and design documents, implementation process, sound design process, and the focus group that we ran after development was complete
Evaluating Tungsten-181 as a High Dose Rate Brachytherapy Source for Treating Cervical Cancer
No full textMiddle energy HDR brachytherapy sources have shown promise to be effective in IMBT use cases. Small thicknesses of shielding, which can fit between the source encapsulation and the inner catheter wall, have shown to be able to cut the dose from middle energy isotopes, such as Ytterbium-169, by up to 60%. Since high energy sources, such as Iridium-192, have dominated the field in the past, there are still more middle energy sources yet to be properly evaluated for clinical use. One such middle energy source is Tungsten-181 (t1/2=121.2 days). W-181 has an average photon energy of 58.9keV and a median photon energy of 57.5keV, making it prime for use in IMBT. High energy sources, and middle energy sources with high energy photons, also require a large degree of room shielding to maintain NRC safety standards to other occupants in the clinic. W-181 emits only two photons with more than 100keV energies, giving it promise for use in unshielded rooms. An activation analysis of W-181 using Catenary Kinetics was executed to determine the specific activity that may be used in a clinical setting and to analyze the shielding implications brought upon Tanatulum-182, an unwanted production byproduct. MCNP6 simulations were used to analyze the dosimetric properties of W-181 used in a novel flex source design adapted for use in a cervical cancer treatment case. This flex source offers the capability to be bent into a ring shape with modular diameters, three diameters were simulated. The effectiveness of a 15° collimation angle was also evaluated for two of the applicator diameters simulated. The outputs of these simulations yielded the absorbed doses to dosimetric reference points as well as to relevant organs at risk. MCNP6 was also used to evaluate the shielding needs of this W-181 source applicator contaminated with Ta-182. To this goal, the source was simulated with typical room shielding conditions, as well as in localized patient shielding conditions. All simulations were repeated with Yb-169 and Ir-192 to serve as bases of comparison in both the dosimetric and shielding evaluations. It was shown with an 8Ci pellet, W-181 can meet dosimetric expectations. The doses to various OARs remain between the three evaluated source materials, however, collimation was shown to reduce the dose from W-181 to certain organs by more than 50%. This intensity modulation application was also effective in lowering the dose to OARs from Yb-169. The W-181 shielding evaluation demonstrated that localized patient shielding is sufficient to abide regulations for doses to members of the public. Additionally, localized shielding proved far more effective against W-181 than Yb-169 or Ir-192. Overall, W-181 is shown to be an effective source for cervical brachytherapy. Given adequate activity, W-181 meets HDR dose rate expectations, while being easier to shield than its HDR counterparts. Its readiness for application in IMBT makes it an extremely promising candidate for uses near radiosensitive tissues, such as cervical brachytherapy. The potential to be used in unshielded rooms with a small amount of patient shielding could increase the availability of cervical brachytherapy to clinics that lack adequate shielding requirements for other HDR sources
Inert Gas Discharge and Extinguishing Dynamics of Total Flooding Systems
No full textTotal flooding clean agents help solve the fire protection problem of suppressing compartment fires without the use of water. Recently, there has been an increased interest in inert gas discharge systems as the Montreal Protocol and its amendments are incentivizing the industry away from halocarbon agents. However, significant questions remain regarding how the standardized extinguishing test, used to certify inert gas systems for use, translates to real-life property protection. Inert gas suppression systems are tested to the UL 2127 and FM 5600 or similar standards. These standardized testing protocols use prescribed fire threats, such as wood cribs, to replicate the fire threat of Class A ordinary solid combustibles. The standardized test contains two criteria: extinguish the test article and prevent test article reignition after a 10-minute soaking period followed by exposure to fresh air. Test article suppression was studied using an inert gas discharge system with IG-100, pure nitrogen, and industry-standard components provided by Kidde-Fenwal, LLC. Two scales were used to research suppression and extinction dynamics: the full 100 cubic meter enclosure and a novel 33 cubic meter with a scaled test article and discharge system. The reduced-scale was proposed to decrease the time, resources, and cost of experimentation. Additional non-standard test articles were utilized at the reduced-scale to increase its validity as a tool for industry use and research. During an inert gas discharge, the test article is subjected to the joint effects of a flow of agent and entrained air and a systematic oxygen reduction. No theoretical framework exists for studying the coupled effects simultaneously. To address this problem, the in-depth heat and mass transfer phenomenon is examined, and a general mass transfer B-Number is proposed for wood cribs. The methodology presented in this work encapsulates the oxygen reduction effects through the B-Number and the forced flow effects through the heat transfer coefficient. The requirements, constraints, and scientific interest of this work formed four natural goals to structure this research. A theme throughout each goal is identifying differences between the industry standard discharge periods of 60 s and 120 s. The first goal is to quantify the full-scale discharge dynamics in terms of the flow of agent and entrained air, oxygen concentration uniformity and rate of change, and test article extinguishing effects. The quantification and characterization of the full-scale enclosure during discharge will greatly influence further testing as well as inform the industry of what is fundamentally occurring during an inert gas discharge. The second goal is to scale the discharge system, test article, and enclosure while maintaining similarity to the previously defined full-scale discharge dynamics. With the reduced-scale enclosure, far more data and understanding can be collected in order to study inert gas discharges better. The third goal is to model the burning rate of the wood crib during the suppression period. This model accounts for the joint effects of forced flow through the crib and the systematic reduction in oxygen concentration. The fourth goal is to investigate the extinction dynamics at the end of the discharge period. Extinction dynamics include the minimum oxygen concentration required for extinguishment, defined as the disappearance of visible flames for more than 3 s
Metal Powder Production with Low Temperature Electrolysis
No full textIn this thesis, we develop a novel method to produce iron powder with CO2-lean process and less energy consumption towards decarbonization. We utilize the low temperature electrolysis (LTE) approach with 3D conductive colloidal electrodes to produce high purity Fe powders (>95%) with high efficiency. We also demonstrate that the process can be used to produce high purity Fe from Cu smelting dust (CSD), which is 98% purity. In addition to Fe, we show that other metal/alloy powders such as Cu, Ag and FeNi, can be produced using the LTE. Moreover, large scale electrolysis system is designed for larger production. Lastly, techno-economic and environmental assessments are performed to evaluate commercialization feasibility and environmental impacts
CorrXWin: A Visible and Infrared image fusion (VIF) Neural Networks Architecture for enhanced object classification in adverse conditions
No full textVisible light image sensors used in photography are susceptible to factors such as adverse light conditions and weather. Infrared sensors are less affected by such adverse conditions but suffer from poor resolution, low contrast, a diminished signal-to-noise ratio, and blurred visual effects. Visible and Infrared Image Fusion (VIF) is an emerging solution that combines visible light images (affected by adverse light conditions, weather) and infrared images (affected by poor resolution, low contrast, a diminished signal-to-noise ratio, blurred visual effects), to substantially improve performance of computer vision applications such as recognition of ships in foggy weather and crowd counting. In this thesis, we propose CorrXWin, an innovative end-to-end architecture that leverages the power of neural networks for performing VIF using Correlation-Driven feature Decomposition Fusion (CDDFuse) and classification of the fused VI image, using Cross-Shaped Window for self-attention (CSWin) transformer. Our work is the first end-to-end architecture that adapts CDDFuse, a robust VIF network, paired with CSwin, a vision transformer network with competitive performance on common vision tasks for general visible image datasets but has not yet been applied to fused VI images. CorrXWin overcomes the number of limitations of existing fusion methods: mainly pixel-level dependency, reliance on external models, high computational overhead and rule-based fusion. This makes CorrXWin a comprehensive solution for VIF, enhancing fusion quality, robustness, and computational efficiency. Additionally, limitations of existing CNN-based classifiers such as the inability to model long range dependencies and the high computational cost of Transformers were overcome by CDDFuse's dual branch CNN-Transformer feature encoder and CSWin's Cross Shaped Window mechanism for self-attention respectively. Rigorous evaluation on a ship type recognition in bad weather dataset demonstrated that the proposed CDDFuse + CSWin method enhances classification performance compared to utilizing only Visible or Infrared images. It achieves a weighted accuracy of 98.9% and an F1 score of 0.9889, outperforming the prior state of the art CNN with linear weighted decision fusion, and other baselines including SwinFusion, MetaFusion fusion methods and SwinV2, DeIT, MobilenetV3, VGG16, VGG19, Resnet50 in classifying the fused VI image. Ablation studies demonstrated that all components of our proposed model contribute to its performance. The proposed method also generalized well, as verified by less than 5% variation in weighted accuracies across all folds in 5-fold Cross Validation. Finally, to interpret the model’s predictions, image quality metrics BRISQUE and SNR were computed, which explained the types of image pairs on which VIF resulted in higher quality images than visual or infrared images alone, and where the proposed method improved classification compared to individual visual or infrared image classifications
Enteroscape: Modeling Infectious Dynamics of the Gut Microbiome in C. elegans
No full textExamining the microbial relationships within the gut microbiome can be difficult with the sheer number of microorganisms present. When gauging the conditions and dynamics of infectious progression, each additional microbe adds a new layer of complexity to consider on top of other treatment obstacles like drug resistance. In the interest of building our understanding of these relationships, we have developed Enteroscape: an in silico agent-based model founded on previous research, laboratory experimentation, and in vivo assays. Enteroscape replicates the infectious progression of pathogenic yeast and the effects of probiotic yeast treatment using the C. elegans intestine. Validated through comparison with real-world laboratory data and observations, Enteroscape portrays not only microbe-microbe interactions but also host-microbe interactions. Through repeated simulations Enteroscape replicates the characteristics of infection observed experimentally including the visual appearance of infectious progression, as well as the effect of probiotic treatment on the host lifespan. While only modeling two types of microbes, Enteroscape demonstrates the effectiveness of computation as a tool for unraveling the complexity of microbial relationships both with each other and their host organism
Intensified Batch to Continuous Conversion of Highly Exothermic Multiphase Pharmaceutical Systems
No full textThe small-molecule pharmaceutical and specialty chemical industries are undergoing a transition from batch to continuous flow operation for processes that can benefit from fast transport in microfluidic reactors. For the case of exothermic and biphasic reactions such as direct oxidation with molecular gases, high surface-to-volume ratio of microreactors provides fast heat transfer, thereby enabling safe and enhanced operation at elevated temperature and pressure. Higher temperatures exponentially increase kinetics, while pressure keeps the solvent in its condensed phase and increases the dissolved gas concentration, thus kinetics. Despite such opportunities, the successful implementation of flow chemistry is occurring at a slow pace, requiring relevant case studies and approaches based on fundamentals of transport and kinetic phenomena to efficiently evaluate the transition from batch to flow and determine optimal operating conditions from bench to production scale. In this work, we have intensified the highly exothermic, biphasic decomposition of hydrogen peroxide from batch to flow by combining heat transfer characterization with transport-kinetic modeling and experiments. Transitioning to continuous microreactors was shown to be a strong process intensification strategy due to orders of magnitude faster cooling, eliminating the risk of thermal runaway. The experimentally observed instability in batch and isothermal behavior in continuous-flow were accurately modeled by incorporating experimentally determined parameters into a transport-kinetic model that accounts for non-idealities like gas hold-up and deviations in heat transfer coefficients. The plug-flow reactor unlocked isothermal operation at extreme reaction conditions that cause major exotherms in batch, resulting in safer and higher throughput processes at scale-up compared to batch reactors of the same volume. We propose a nondimensional regime map based on the conservative Semenov criteria for thermal runaway as a tool to identify operating windows for stable and high throughput production when evaluating batch to continuous process conversion
#TeamGraduate: Using AI to enhance online learning for adult students
No full text#TeamGraduate was founded by Helena Mboti to give students a second chance at furthering their future by getting their GED. The goal of this project is to integrate AI into #TeamGraduate’s operations to enhance content creation, personalize learning experiences, and optimize user interaction. Through research on AI systems and interviews with both students and educators, we developed and tested a successful AI prototype for the #TeamGraduate website
Design and Fabrication of an Apparatus to Evaluate the Dynamic Loading Response of Aerospace Materials
No full textNumerous aerospace applications, including the impact of aircraft landing gear, meteorite impacts on satellites, and bird ingestion in engines, have motivated research on the dynamic tensile behavior of aerospace alloys. The objective of this project is to design and fabricate a state-of-the-art Split-Hopkinson Tensile Pressure Bar (SHTPB) testing setup to study the tensile response of aluminum and titanium alloys under dynamic loading (at strain rates from 500 s-1 to 2000 s-1). The project focused on modifying the existing compressive testing apparatus to facilitate successful dynamic tensile tests. In particular, the team designed and built various components of the SHTPB, including a single-stage gas gun capable of launching projectiles up to 100 m/s, specimen grips, and other mechanical components. The team developed various tools, such as optical sensors to measure the projectile velocity for data acquisition, and MATLAB-based code to post-process the experimental strain data and determine the stress-strain response of the materials. The accuracy and functionality of the apparatus have been demonstrated by testing the fabricated specimens and comparing the results with data available in literature, as well as data obtained from DIC and FEA simulations. The experimental data obtained using the SHTPB have provided tremendous insight into the role of fabrication processes and the subsequent microstructure on the anisotropic and rate-dependent dynamic tensile response of these alloys
Developing a Business and Financial Model for the Natural Resources Polytechnic Institute of Southern Africa
No full textNamibia is missing out on opportunities to improve its economy and create more jobs in the local communities because it does not fully process minerals before exporting them. The Natural Resources Polytechnic Institute of Southern Africa (NaRPISA) aims to fill this void by providing the necessary skills required to fulfill these tasks in the country. Our project aimed to provide a business plan that includes a financial plan, personnel plan, learning system technology needs, and administration software needs for NaRPISA. To achieve this aim, we conducted a mixed-methods research design with semi-structured in-depth interviews, an on-site observation, and secondary data research. 11 interviews were conducted with members of the following groups: businesspeople, mining officials, school faculty, and people in the IT department. On-site observations were conducted on a diamond mine, and for secondary data, we researched documentation from the government, lobbying groups, and universities concerning mining/mining value addition. Our analysis shows that while there will likely be investor interest, it will be difficult to gather substantial funds for the institution, mostly due to the high costs, numbering in the millions of dollars that would be required to create the institution. Using Google Finance, a proper financial model was set up that allowed us to determine the cost breakdown of NaRPISA. As for the hybrid model, the software Moodle is free and is sufficient for online learning amongst other universities, such as NUST and UNAM. Administration-wise, the software ITS is expensive, but the only viable and realistic option. As for gauging student interest, there could be potential interest in both large- and small-scale mining, however, each has its risks. Large-scale mining would likely gather much more money, but large-scale mining is unlikely to be willing to associate with a new university focused on mining value addition, especially since they are already teaching their miners mining value addition. On the other hand, small-scale mining has a large populace who could likely benefit from an understanding of mining value addition, but the sector is unregulated, and many of them are unlikely to be able to adapt to the hybrid learning aspect due to limited access to electricity and the internet. With the development of our business model for NaRPISA, the results show that starting this institute comes along with many challenges related to the high costs and low possibility for return on investment. If investors and sponsors can make this institute come to life, it will serve as a benefit to the economy of Namibia as a whole, and in turn will help flourish the local job markets and the people within these communities