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Model-Based Evaluation of Energy Systems for Multirotor UAV Based on Batteries and Fuel Cells
Get PDFIn this study, two multirotor unmanned aerial vehicle (UAV) energy systems are comparatively evaluated via a modelling process, namely a battery electric system and a hybrid fuel cell and battery system. Technical, economic, and ecological evaluation parameters are considered. The evaluation is performed on three different mission types: a 10 km delivery mission, a 3000 m2 facade inspection, and a nine-minute drone show, to represent the transport, monitoring, and event sectors. Results are calculated via a modelling process first simulating the required power profiles for each mission and then simulating both energy systems’ operational behavior during each mission. The resulting technical parameters show that the battery electric UAV has 1.7 times higher efficiency than the fuel cell hybrid UAV. However, the fuel cell hybrid UAV allows potential flight durations 3.1 times longer than the battery electric UAV. Considering economic parameters, the battery electric UAV is the more economical choice due to the higher investment costs of the fuel cell hybrid UAV, even when considering future cost developments for investment and energy costs. For ecological parameters, the fuel cell hybrid UAV has the potential to produce significantly less emissions, but only when using hydrogen produced from renewable energy (green hydrogen). All in all, the battery electric UAV is sufficient for the three concrete missions considered and should be chosen over the fuel cell hybrid UAV. However, the fuel cell hybrid UAV should be considered for missions with longer required flight times than the battery electric UAV is capable of, especially in the transport and monitoring sectors
Oppressive Authority: Dismantling, Reexamining, and Reconstructing Notions of Authority in Information Literacy Instruction
Get PDFThe following chapter examines ways knowledge authority structures can be oppressive in relation to information literacy instruction and discusses how librarians can implement equitable and inclusive pedagogy in their library instruction by dismantling, reexamining, and reconstructing notions of authority
Safety Management of Wildlife Hazards to Aviation: An Analysis of Wildlife Strikes in Part 139 Airports in Florida 2011–2020
Get PDFPurpose: The purpose of this study was threefold: (1) to investigate wildlife strike reporting trends in Part 139 airports in the state of Florida (2011–2020); (2) to evaluate the existence of a difference in the rate of reported wildlife strikes between the seasons of the year (2011–2020); and (3) to develop information based upon the data analyzed that can be used for the safety management of wildlife hazards in Florida.Design/methodology: The researchers in this study answered the research questions through the analyses, revision, and evaluation of existing wildlife strike and aircraft operations data. The data analyzed in this study were collected between May 1 and May 20, 2021. The researchers used the Federal Aviation Administration Air Traffic Activity System and the National Wildlife Strike Database to collect information on aircraft operations and reported wildlife strikes, respectively. Findings: There were 8,977 and 458 wildlife strikes and damaging strikes, respectively, at and around Part 139 airports in Florida from 2011 through 2020. The majority of strikes (62.6%) and damaging strikes (62%) occurred during the arrival phases of flight. The number of strikes increased almost 37% from 2011 (N 5 614) to 2020 (N 5 837). Additionally, the number of strikes per 100,000 aircraft operations (wildlife strike index) increased from 18.6 to 28.62 during the same period. Aggregate data indicated the risk of strikes is higher during the fall and summer seasons of the year.Originality/value: This study provides valuable information by addressing a gap in published wildlife strike government reports and studies using wildlife strike and aircraft operations data at a regional level. Information obtained from the scientific analyses of wildlife strike data is vital for effective wildlife hazard management programs of aviation stakeholders. Findings of this study can be used by airport operators to improve their wildlife strike mitigation efforts. Also, findings can provide the empirical foundation for integrated research and the development of national and regional standards to enhance aviation safety
Method for estimating pulsatile wall shear stress from one-dimensional velocity waveforms
Get PDFWall shear stress (WSS)—a key regulator of endothelial function—is commonly estimated in vivo using simplified mathematical models based on Poiseuille\u27s flow, assuming a quasi-steady parabolic velocity distribution, despite evidence that more rapidly time-varying, pulsatile blood flow during each cardiac cycle modulates flow-mediated dilation (FMD) in large arteries of healthy subjects. More exact and accurate models based on the well-established Womersley solution for rapidly changing blood flow have not been adopted clinically, potentially because the Womersley solution relies on the local pressure gradient, which is difficult to measure non-invasively. We have developed an open-source method for automatic reconstruction of unsteady, Womersley-derived velocity profiles, and WSS in conduit arteries. The proposed method (available online at https://doi.org/10.5281/zenodo.7576408) requires only the time-averaged diameter of the vessel and time-varying velocity data available from non-invasive imaging such as Doppler ultrasound. Validation of the method with subject-specific computational fluid dynamics and application to synthetic velocity waveforms in the common carotid, brachial, and femoral arteries reveals that the Poiseuille solution underestimates peak WSS 38.5%–55.1% during the acceleration and deceleration phases of systole and underestimates or neglects retrograde WSS. Following evidence that oscillatory shear significantly augments vasodilator production, it is plausible that mischaracterization of the shear stimulus by assuming parabolic flow leads to systematic underestimates of important biological effects of time-varying blood velocity in conduit arteries
Reducing Construction Change Orders With 3D CIM Technology
Get PDFAs long as 2D paper plans are the construction contract document, 3D Civil Information Management (CIM) technology will improve bid-ability, constructability, and overall plan quality. The CIM process leverages modeling technology to reverse engineer 2D plans and build the project electronically prior to letting. Used with engineering best practices, CIM identifies plan errors, conflicts, and other challenges which ultimately reduce construction change orders. Featured projects will include I-69 in Bloomington and the Ohio River Bridges
Indiana’s 1st Displaced Left Turn Intersection
No full textIndiana’s first displaced left-turn intersection was completed in the fall of 2022 at the intersection of US 31 and SR 135/Thompson Road on Indy’s south side. Join this presentation to learn why the project was needed, the design and construction challenges that were over- come, how this project was presented to the public, and how it is operating today
Designing to Avoid Impacts to Utilties
Get PDFFHWA and INDOT have communicated for some time that successful project designs should avoid impacting utilities to lower risk and improve reliability in delivery. The question is, “When is it feasible?” To answer that question, this session engages participants with various project situations and design considerations to evaluate the feasibility of designing to avoid utilities. Participants from design, ROW, construction, and utility coordination will have the opportunity to interact in this “gamified” discussion
Environmental Assessments on a Local Project
Get PDFThis presentation will go through the environmental process of a recent $125M local project within Noblesville. What are the major differences between the National Environmental Policy Act (NEPA) and State Environmental Policy Act (SEPA) process as it relates to an environmental assessment (EA)? What is required, what is not required, and what is optional? How long does the process take? Join us as we walk through this exciting process and experience
Notes to my Dad
Get PDFThis is a critical reflection of my experience navigating higher education as a Hmong woman. My dad is well known among our clan to be very “traditional” and respectable. However, over the past 6 years during my graduate studies, my dad has remained my number one supporter. I sometimes, I tell him he is the chosen one, to derail his beliefs. At times, I begin to imagine what life would be like if I were a son. As for me, one of my mentors told me one time, that it is my sacred path to do this work. I have since then began my project of learning and being a Hmong woman. Like Anzaldua’s autohistoria, I write from within. I know my ancestors have waited for me to do this work. I am still grappling with the meaning (s) of feminism. What does Hmong feminism look like