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Ballistics Characterization of Micro-Truss Reinforced Lunar-Inspired Geopolymer Concrete for Space Construction
No full textThis research investigates the ballistics response and compressive strength of a Fly Ash/ Lunar Regolith hybrid geopolymer concrete developed for space construction. The study aimed firstly to optimize the Fly Ash/ Regolith mix ratio for maximum mechanical performance and secondly, to evaluate the effectiveness of carbon-fiber micro-truss reinforcement, produced by 3D printing, in mitigating damage from high-velocity impacts. Concrete specimens with varying Fly Ash-to-Regolith ratios (100-50% Fly Ash) were fabricated and tested under compression and ballistic loading. Compressive strength tests followed ASTM C109 using a 110 Kip 810-MTS testing apparatus on both unreinforced and reinforced 2” cubes. For unreinforced samples, average compressive strengths ranged between 4,002-5,485 psi with the highest compressive strength value corresponding to the 90% Fly Ash/ Regolith mix ratio. The lowest strength value was seen in the 60% Fly Ash mix ratio but only showed a 27% decrease from the optimal 90% mix. All the mixes achieved strengths within the range of standard structural concrete. The reinforced samples yielded compressive strengths in the 2237-3349 psi range with the highest strength value corresponding again to the 90% Fly Ash/ Regolith mix ratio which is consistent with the unreinforced sample results. While it did not increase compressive strength, reinforcing the samples seemed to homogenize results across Fly Ash/ Regolith mix ratios yielding similar compressive strength results as more Regolith was added when compared to the unreinforced sample set. Ballistic performance was assessed on 6x6x0.75” panels using a pneumatic launcher at 1000 psi. Energy absorption was found using the MotionPro Y4-S3 High Speed Camera with 1024x160 image resolution at 30,000 fps to perform Digital Image Correlation (DIC) with ProAnalyst (Woburn, MA) software. Unreinforced samples absorbed 105-130 ft-lb of impact energy, while reinforced samples absorbed 74-115 ft-lb, with both sets showing maximum absorption near the 80% Fly Ash/ Regolith ratio. Reinforcement did not increase overall energy absorption across all mix ratios but proved effective in localizing damage and preventing catastrophic failure - a critical factor for maintaining load-bearing capacity under impact. Overall, the optimal Fly Ash/ Lunar Regolith ratio was identified between 80-90% Fly Ash, offering a balance between compressive strength, energy absorption, and material efficiency. These results demonstrate that reinforced geopolymer composites incorporating lunar regolith simulants can provide durable, impact resistant, and sustainable materials for future lunar infrastructure
Investigating The Effectiveness of a Job Crafting Workshop
No full textThere is a need for colleges and universities to better prepare students for future careers. One potential way colleges and universities can go about preparing students for their future careers is by embedding career development supports into existing programs and courses for undergraduates. Job crafting, or the process by which individuals actively shape their own work, has been shown to support the well-being and retention of employees in various careers. In addition, previous studies show that individuals can gain knowledge about and confidence to job craft through professional development. My study tests the effectiveness of a workshop designed to support the development of job crafting, with the intention of supporting undergraduate students’ career preparation. Quantitative and qualitative data were collected with participants completing a pre- and post-survey before and after the workshop. Results demonstrated that the workshop effectively introduced participants to the process of job crafting. We are working to develop this workshop into a concise lesson plan that can be presented in any academic setting
Personalized 3D-Printed Tablets for Diabetes and Related Complications: Design, Optimization, and Evaluation
No full textThis study aimed to explore potential use of pneumatic-based thermoplastic 3D bioprinter to create personalized tablets in a single-step process. In investigates the development of a single pill containing two model drugs: Metformin HCl (a highly soluble drug) for extended-release and Atorvastatin Calcium Trihydrate (a low-solubility drug) for immediate release with enhanced solubility. To achieve this, Eudragit RSPO as extended-release polymer and Polyethylene Oxide (PEO N10) as immediate release polymer was used, and the tablets were fabricated using Direct Powder Extrusion (DPE) Technology with pneumatic-based thermoplastic print heads. Key processing parameters, such as nozzle printing speed, infill density, printhead temperature, print bed temperature, and external pressure, were carefully optimized to ensure that the fabricated tablets met the desired specifications. The tablets were designed in an oval shape and printed using a rectilinear pattern with 25% and 100% infill densities to study the impact of infill on drug release. After printing, the tablets were thoroughly characterized using advanced analytical techniques, including Differential Scanning Calorimetry (DSC), Fourier-Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Mass Spectrophotometry (MS) and drug content assessment and in vitro dissolution studies. These tests helped evaluate the tablets’ thermal stability, drug-polymer interactions, surface morphology, drug content and drug release profiles. For Metformin HCl, the MET-1 to MET-7 formulations showed excellent printability, with the MET-7 formulation achieving about 90% drug release over 10 hours, making it suitable for extended-release applications. For Atorvastatin Calcium, the ACT-2, ACT-3, ACT-4, ACT-7, ACT-10, and ACT-11 formulations demonstrated good printability, with the ACT-11 formulation releasing 89% of the drug within 30 minutes in a pH 6.8 phosphate buffer, meeting the criteria for immediate release. Overall, this study highlights the potential use of Direct Powder Extrusion based 3D printing as a groundbreaking technology for producing personalized tablets. By combining the benefits of hot-melt extrusion and fused deposition modeling into an alternative single-step process, this approach offers a versatile and efficient method for creating customized drug delivery systems tailored to individual patient needs for personalized medication