A Coupled Lattice Boltzmann-Extended Finite Element Model for Fluid-Structure Interaction Simulation with Crack Propagation

Fatigue cracking of structures in fluid-structure interaction (FSI) applications is a pervasive issue that impacts a broad spectrum of engineering activities, ranging from large-scale ocean engineering and aerospace structures to bio-medical prosthetics. Fatigue is a particular concern in the offshore drilling industry where the problem is exacerbated by environmental degradation, and where structural failure can have substantial financial and environmental ramifications. As a result, interest has grown for the development of structural health monitoring (SHM) schemes for FSI applications that promote early damage detection. FSI simulation provides a practical and efficient means for evaluating and training SHM approaches for FSI applications, and for improving fatigue life predictions through robust parametric studies that address uncertainties in both crack propagation and FSI response. To this end, this paper presents a numerical modeling approach for simulating FSI response with crack propagation. The modeling approach couples a massively parallel lattice Boltzmann fluid solver, executed on a graphics processing unit (GPU) device, with an extended finite element (XFE) solid solver. Two-way interaction is provided by an immersed boundary coupling scheme, in which a Lagrangian solid mesh moves on top of a fixed Eulerian fluid grid. The theoretical basis and numerical implementation of the modeling approach are presented, along with a simple demonstration problem involving subcritical crack growth in a flexible beam subject to vortex-induced vibration

Children\u27s Hospital Animatronic

This senior project explores the development of a pediatric-oriented animatronic designed to enhance the hospital experience for children. Recognizing the importance of alleviating the anxiety and fear that often accompany hospital visits, the project focuses on creating an engaging and interactive companion to soothe children. Key components of this project include: Creative Design: The animatronic character\u27s design prioritizes child-friendliness, employing research into child psychology and preferences to ensure an appealing and approachable aesthetic. Electrical and Mechanical Engineering: A robust mechanical and electronic system was engineered to enable lifelike movements, gestures, and responses. Interactive Features: A simple, user-friendly app will be available for patients, hospital employees and volunteers to use. The app will allow users to select pre-programmed responses and behaviors for the animatronic to exhibit. This project presents a promising solution to enhance the pediatric hospital experience, providing companionship and enrichment for patients. Future work may focus on further refinements, expanded capabilities, and long-term impact assessment. Ultimately, this animatronic offers a valuable tool for compassionate pediatric care in hospitals

Ultra-High-Resolution Patterning And Pattern Transfer Via Nanocrystal Colloidal Lithography

The ability to design, pattern, and process materials at the nanoscale has enabled vast research opportunities ranging from fundamental science to technological applications and device integration. The continued development of nanoscience and nanotechnology relies on pushing the limits of nanoscale fabrication capabilities. After decades of development, this frontier has moved to the sub-10 nm length scale to explore novel physical properties and functionalities for next-generation technology. However, conventional “top-down” strategies that have carried nanofabrication to this point have severe limitations for practically improving the resolution capabilities of deep nanoscale fabrication. In this dissertation, we demonstrate ultra-high-resolution patterning and pattern transfer using nanocrystal (NC) colloidal lithography. This innovative nanofabrication platform integrates bottom-up methods, that combine NC synthesis and self-assembly approaches, with well-established top-down techniques such as dry etching and thin film deposition. We employ monodisperse NC building blocks with self-assembly methods to establish high-density, well-ordered patterns, where the inorganic core of each NC serves as a discrete hard mask used for high-fidelity pattern transfer into a desired substrate material. We demonstrate the use of isotropic NCs to establish various sub-10 nm pattern morphologies and examine the stability of the NC pattern upon dry etching, comparing NC monolayers and bilayers. We extend the NC colloidal lithography scheme using anisotropic NCs to demonstrate high-density, anisotropic pattern transfer into various substrate materials down to the sub-5 nm regime. The presented fabrication strategy offers further opportunities to leverage various combinations of NC morphologies and materials afforded by the extensive NC library for more complex pattern design. Additionally, this approach can be extended to process various substrate material classes at the deep nanoscale. The NC colloidal lithography platform enables broader access to single-digit nanoscale fabrication for the scientific community worldwide, which could impact various research sectors ranging from integrated circuits to memory devices, optoelectronics, metasurfaces, quantum devices and more

VFR-into-IMC: An Analysis of Two Training Protocols on Weather-Related Posttest Scores

According to the Aircraft Owners and Pilots Association Air Safety Institute, 264 accidents were identified as continued visual flight rules (VFR) into instrument meteorological conditions (IMC), during the past ten years. Approximately 89% of those VFR-into-IMC accidents were fatal, causing hundreds of deaths. VFR-into-IMC has been a major concern for the general aviation community, prompting focused efforts. Research, data analyses, outreach, training, and education are recommended practices to address risks associated with VFR-into-IMC. Researchers of the current study sought to evaluate the cause and effect relationship between two training protocols and weather-related posttest scores. A pretest–posttest experimental design was utilized at two testing locations. Participants were randomly assigned to one of three groups: a control group, an interactive online training group, or an interactive workshop group. An analysis of covariance was used to determine whether there was a significant difference between mean posttest scores among the experimental groups while controlling for pretest scores. The treatments did not appear to significantly increase posttest scores after controlling for pretest scores, at either experiment location. Though the results of this study did not yield anticipated findings, much was learned and potentially helpful to general aviation researchers seeking to mitigate VFR-into-IMC encounters. Recommendations for future research and practices are discussed

miEAA 2.0: integrating multi-species microRNA enrichment analysis and workflow management systems

Gene set enrichment analysis has become one of the most frequently used applications in molecular biology research. Originally developed for gene sets, the same statistical principles are now available for all omics types. In 2016, we published the miRNA enrichment analysis and annotation tool (miEAA) for human precursor and mature miRNAs. Here, we present miEAA 2.0, supporting miRNA input from ten frequently investigated organisms. To facilitate inclusion of miEAA in workflow systems, we implemented an Application Programming Interface (API). Users can perform miRNA set enrichment analysis using either the web-interface, a dedicated Python package, or custom remote clients. Moreover, the number of category sets was raised by an order of magnitude. We implemented novel categories like annotation confidence level or localisation in biological compartments. In combination with the miRBase miRNA-version and miRNA-to-precursor converters, miEAA supports research settings where older releases of miRBase are in use. The web server also offers novel comprehensive visualizations such as heatmaps and running sum curves with background distributions. We demonstrate the new features with case studies for human kidney cancer, a biomarker study on Parkinson’s disease from the PPMI cohort, and a mouse model for breast cancer. The tool is freely accessible at: https://www.ccb.uni-saarland.de/mieaa2

VFR-into-IMC Accident Trends: Perceptions of Deficiencies in Training

Pilots who operate under visual flight rules (VFR) and in visual meteorological conditions, who then continue flight into instrument meteorological conditions (IMC), remain as one of the leading causes of fatal aircraft accidents in general aviation. This paper examines past and current research initiatives, in seeking to identify causal factors and gaps in training that lead to VFR-into-IMC aircraft accidents, using a mixed methods approach. The Aircraft Owners and Pilots Association Air Safety Institute database and the National Transportation Safety Board database search engines were used to identify accident reports associated with VFR flight into IMC/deteriorating weather conditions for a 10-year time period (2003 to 2012). A national survey was also conducted to gain deeper insight into the self-identified training deficiencies of pilots. There is evidence that situational awareness is linked to decision-making, and there is a lack of proper training with regards to weather and weather technology concepts, making it difficult for pilots to gain these knowledge areas, skills, and abilities throughout their initial flight training and subsequent experience

Exploration of cerebral hemodynamic pathways through which large artery function affects neurovascular coupling in young women

Background The interactions between large artery function and neurovascular coupling (NVC) are emerging as important contributors to cognitive health. Women are disproportionally affected by Alzheimer's disease and related dementia later in life. Understanding large artery correlates of NVC in young women may help with preservation of cognitive health with advancing age. Purpose To explore the association between large artery function, NVC and cognitive performance in young women. Methods Vascular measurements were made in 61 women (21 ± 4 yrs) at rest and during a cognitive challenge (Stroop task). Transcranial Doppler was used to measure left middle cerebral artery (MCA) maximum velocity (Vmax), mean velocity (Vmean), and pulsatility index (PI). NVC was determined as MCA blood velocity reactivity to the Stroop task. Large artery function was determined using carotid-femoral pulse wave velocity (cfPWV) as a proxy measure of aortic stiffness and carotid ultrasound-derived measures of compliance and reactivity (diameter change to the Stroop task). Cognitive function was assessed separately using a computerized neurocognitive battery that included appraisal of response speed, executive function, information processing efficiency, memory, attention/concentration, and impulsivity. Results MCA Vmax reactivity was positively associated with executive function (β = 0.26, 95% CI 0.01–0.10); MCA Vmean reactivity was negatively associated with response speed (β = −0.33, 95% CI −0.19 to −0.02) and positively with memory score (β = 0.28, 95% CI 0.01–0.19). MCA PI reactivity was negatively associated with attention performance (β = −0.29, 95% CI −14.9 to −1.0). Path analyses identified significant paths (p < 0.05) between carotid compliance and carotid diameter reactivity to select domains of cognitive function through MCA reactivity. Conclusions NVC was associated with cognitive function in young women. Carotid artery function assessed as carotid compliance and carotid reactivity may contribute to optimal NVC in young women through increased blood flow delivery and reduced blood flow pulsatility