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Charles, Se´bastien, Benoı^t Eynard, Peter Bartholomew e Christian Paleczny. "Standardization of the Finite Element Analysis Data-Exchange in Aeronautics Concurrent Engineering". Journal of Computing and Information Science in Engineering 5, n. 1 (1 marzo 2005): 63–66. http://dx.doi.org/10.1115/1.1861474.
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The paper presents some research and a business case study carried out in a European project focused on Concurrent Engineering and the implementation of data exchange standards in the aeronautics industry. It deals with the use of the STEP AP209 standard dedicated to the exchange of finite element analysis data. Applied in the context of Concurrent Engineering within the extended enterprise, the STEP AP209 standard should enhance the communication, exchange, and sharing of product data between mechanical engineering and analysis experts across distributed sites. The development of a translator from STEP AP209 to SAMCEF (commercial FE solver) has been carried out and evaluated on an aircraft engine component.
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Jansen, Ralph H., Cheryl L. Bowman, Sean Clarke, David Avanesian, Paula J. Dempsey e Rodger W. Dyson. "NASA electrified aircraft propulsion efforts". Aircraft Engineering and Aerospace Technology 92, n. 5 (6 dicembre 2019): 667–73. http://dx.doi.org/10.1108/aeat-05-2019-0098.
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Purpose This paper aims to review national aeronautics and space administration (NASA’s) broad investments in electrified aircraft propulsion (EAP). NASA investments are guided by an assessment of potential market impacts, technical key performance parameters, and technology readiness attained through a combination of studies, enabling fundamental research and flight research. Design/methodology/approach The impact of EAP varies by market and NASA is considering three markets as follows: national/international, on-demand mobility and short-haul regional air transport. Technical advances in key areas have been made that indicate EAP is a viable technology. Flight research is underway to demonstrate integrated solutions and inform standards and certification processes. Findings A key finding is that sufficient technical advances in key areas have been made, which indicate EAP is a viable technology for aircraft. Significant progress has been made to reduce EAP adoption barriers and further work is needed to transition the technology to a commercial product and improve the technology, so it is applicable to large transonic aircraft. Practical implications Significant progress has been made to reduce EAP adoption barriers and further work is needed to transition the technology to a commercial product and improve the technology, so it is applicable to large transonic aircraft. Originality/value This paper will review the activities of the hybrid gas-electric subproject of the Advanced Air Transport Technology Project, the Revolutionary Vertical Lift Technology Project and the X-57 Flight Demonstration Project, and discuss the potential EAP benefits for commercial and military applications. This paper focuses on the vehicle-related activities, however, there are related NASA activities in air space management and vehicle autonomy activities, as well as a breakthrough technology project called the Convergent Aeronautics Solutions Project. The target audience is people interested in EAP.
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Di Lorenzo, Giuseppe, Emma Frosina, Luigi De Petrillo, Davide Lauria, Adolfo Senatore, Francesco Curreri, Guido Saccone, Marcello Kivel Mazuy e Ciro Pascarella. "Design and Development of Hybrid-Electric Propulsion Model for Aeronautics". MATEC Web of Conferences 304 (2019): 03012. http://dx.doi.org/10.1051/matecconf/201930403012.
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Nowadays, worldwide environmental issue, associated to reduction of pollutant and greenhouse emissions are gaining considerable attention. Aviation sector contribution to the whole CO2 released accounts to around 2%, but it is expected to grow in the next future due to increase of demand. Probably, combustion engine design and fuel efficiency have already reached their optimum technology level and only a breakthrough as hybrid-electric propulsion could be able to satisfy the new international more demanding requirements. However, an improvement of the technology readiness level of hybrid-electric propulsion is strongly necessary and many operational and safety challenges should be addressed. In the work here reported, a hybrid-electric model was designed and developed for general aviation aircrafts, by means of the Mathworks® Matlab – Simulink 1D/0D simulation environment. Both thermal and electric energy storage units, transmission systems and power management devices were considered and the overall performances were evaluated during cruise phase and a conventional training mission, characterized by several run(lap) “touch-and-go”. Furthermore, an innovative mathematical methodology was implemented for battery pack discharge profile interpolation. Finally, reliability and accuracy of the new proposed model were evaluated through comparison with the commercial code Simcenter AMESim® software and an average bias only equal to 5% was achieved.
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Stutte, Gary W. "Commercial Transition to LEDs: A Pathway to High-value Products". HortScience 50, n. 9 (settembre 2015): 1297–300. http://dx.doi.org/10.21273/hortsci.50.9.1297.
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The use of light-emitting diodes (LEDs) to support plant growth is a radical departure from use of gas-discharge lamps, which were developed in mid-19th and widely adopted by the industry during the 20th century. Initial investigation by the National Aeronautics and Space Administration (NASA) in the late 1980s on the use of LEDs to grow plant in space is resulting in an industry-wide transition from gas discharge to solid-state lighting systems. This global transformation is given urgency by national policies to reduce energy consumption and being facilitated by ready access to information on LEDs. The combination of research, government policy, and information technology has resulted in an exponential increase in research into the use and application of LED technology in horticulture. Commercial horticulture has identified the opportunities provided by LEDs to optimize light spectra to promote growth, regulate morphology, increase nutrient content, and reduce operating costs. LED-light technology is enabling the development of innovative lighting systems, and is being incorporated into large-scale plant factories for the production of edible, ornamental, and medicinal plants. An overview of prevalence of readily accessible information on LEDs and implications for future adoption in horticulture is discussed.
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Giublin, B., J. A. Vieira, T. G. Vieira, L. G. Trabasso e C. A. Martins. "Experimental analysis of the automated process of sanding aircraft surfaces". Aeronautical Journal 118, n. 1199 (gennaio 2014): 53–64. http://dx.doi.org/10.1017/s0001924000008927.
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Abstract ITA and EMBRAER are currently executing the research project Automation of Aircraft Structural Assembly (AASA) whose goal is to implement a robotic cell for automating the riveting process of aeronautical structures. The proposal described herein complements the AASA project, adds other manufacturing processes, namely sanding and polishing of aircraft surfaces. To implement the additional processes AASA project resources and facilities were used (robots and metrology systems) and devices designed and /or acquired to allow sharing of these resources. Among these, an Automatic Tooling Support for AERonautics structures (ATS_AER) was designed and built; also, a robot tool changer with high load capacity was acquired. The outcome of this research project is the evaluation of the feasibility of automating the processes of sanding and polishing metal surfaces in the aircraft manufacture using robots. The operating method adopted for surface treatment employed the ‘U’ type trajectory optimised to be run by a KUKA robot KR 500. The sanding process has been applied to aluminum metal sheet specimen sized 2•18ft2 (0•20m2) and used commercial 600 and 800 sandpaper. The automated sanding process yielded an average value of RA 0•48 ± 0•08 which is 25% more efficient when compared to the traditional, manual process whose average value of RA is 0•75 ± 0•51.
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Crawford, Hannah. "NASA’s Time to Shine: Approaching Procurement in the ‘New Space Age’". Air and Space Law 46, Issue 6 (1 novembre 2021): 649–64. http://dx.doi.org/10.54648/aila2021043.
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With the increasing presence of commercial activity in outer space, the dynamics between public and private entities are shifting. Within these changing dynamics, the role of private actors pose novel opportunities and unprecedented challenges to space agencies. This article considers the role National Aeronautics and Space Administration (NASA) has undertaken in seeking to redefine and maximize the potential these new relationships. Paying attention to how these innovative mechanisms have enabled NASA to rediscover its direction and regenerate its mission; catapulting itself to the forefront of the New Space Age, the paper analyses whether NASA truly sets a precedent for other nations and agencies to follow-suit. NASA, ESA, JAXA, Procurement, Contracts
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Vrancken, Patrick, e Jonas Herbst. "Development and Test of a Fringe-Imaging Direct-Detection Doppler Wind Lidar for Aeronautics". EPJ Web of Conferences 237 (2020): 07008. http://dx.doi.org/10.1051/epjconf/202023707008.
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DLR currently investigates the use of Doppler wind lidar as sensor within feedforward gust alleviation control loops on fast-flying fixed-wing aircraft. Such a scheme imposes strong requirements on the lidar system such as sub-m/s precision, high rate, high spatial resolution, close measurement ranges and sensitivity to mixed and pure molecular backscatter. We report on the development of a novel direct-detection Doppler wind lidar (DD-DWL) within these requirements. This DD-DWL is based on fringe-imaging of the Doppler-shifted backscatter of UV laser pulses in a field-widened Michelson interferometer using a fast linear photodetector. A prototype for airborne operation has been ground-tested in early 2018 against a commercial coherent DWL, demonstrating its ability of measuring close-range wind speeds with a precision of 0.5 m/s, independent of the actual wind speed.
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STEFAN, Adriana, George PELIN, Cristina-Elisabeta PELIN, Alexandra-Raluca PETRE e Monica MARIN. "Manufacturing process, mechanical behavior and modeling of composites structures sandwich panel". INCAS BULLETIN 13, n. 1 (5 marzo 2021): 183–91. http://dx.doi.org/10.13111/2066-8201.2021.13.1.19.
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The complexity of sandwich structures is a challenge for aeronautics designers. Sandwich construction is widely used in both the aerospace and commercial industries because it is an extremely lightweight structural approach with high rigidity and strength/weight ratios. Although today's technology offers the possibility to combine a variety of materials for these structure solutions, in aviation only a few materials are accepted. This paper presents the technological process of making these sandwich structures, as well as a study of the characterization and testing of a sandwich structure to analyze the behavior from a mechanical point of view. The conclusions of the paper represent an experimental basis on which further research will be built.
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Menale, Carla, Stefano Constà, Vincenzo Sglavo, Livia Della Seta e Roberto Bubbico. "Experimental Investigation of Overdischarge Effects on Commercial Li-Ion Cells". Energies 15, n. 22 (11 novembre 2022): 8440. http://dx.doi.org/10.3390/en15228440.
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Due to their attractive properties, such as high energy and power density, Lithium-ion batteries are currently the most suitable energy storage system for powering portable electronic equipment, electric vehicles, etc. However, they are still affected by safety and stability problems that need to be solved to allow a wider range of applications, especially for critical areas such as power networks and aeronautics. In this paper, the issue of overdischarge abuse has been addressed on Lithium-ion cells with different anode materials: a graphite-based anode and a Lithium Titanate Oxide (LTO)-based anode model. Tests were carried out at different depths of discharge (DOD%) in order to determine the effect of DOD% on cell performance and the critical conditions that often make the cell fail irreversibly. Tests on graphite anode cells have shown that at DOD% higher than 110% the cell is damaged irreversibly; while at DOD% lower than 110% electrolyte deposits form on the anodic surface and structural damage affects the cathode during cycling after the overdischarge. Furthermore, at any DOD%, copper deposits are found on the anode. In contrast with the graphite anode, it was always possible to recharge the LTO-based anode cells and restore their operation, though in the case of DOD% of 140% a drastic reduction in the recovered capacity was observed. In no case was there any venting of the cell, or any explosive event.
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A. Melograna, Catrina. "Space for Challenges: NASA’s Protest Process Makes Procurement Fairer and More Transparent". Air and Space Law 47, Issue 3 (1 luglio 2022): 331–46. http://dx.doi.org/10.54648/aila2022018.
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This article examines the National Aeronautics and Space Administration (NASA) procurement system broadly, starting from the top down with further examination of the protest process. It asks whether the protest process ensures fairness and transparency in the competition between commercial companies to win the contracts solicited by NASA. As a case study on the protest process, and to help answer the question, the article examines the recent Blue Origin protest regarding the Human Landing System and the SpaceX lunar lander contract award. Finally, the article concludes that the protest procedure is vital in ensuring the procurement process is fair and that NASA is held accountable for its decisions when it comes to spending public funds. NASA Procurement System, NASA, SpaceX, Blue Origin, Protest Process
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Guglieri, G. "Effect of autopilot modes on flight performances of electric mini-UAVs". Aeronautical Journal 117, n. 1187 (gennaio 2013): 57–69. http://dx.doi.org/10.1017/s0001924000007752.
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Abstract Great attention is focused on the development of both remotely controlled and unmanned flying vehicles. As a matter of fact, the design of such vehicles is a topical direction of development for modern aeronautics. Among such promising flying vehicles, micro- and mini-UAVs play a leading role. The present paper proposes a method to validate the inclusion of the relevant modelling elements in a comprehensive simulation tool reproducing some of the flight phases of a mini-UAV. The energy balance budget and the dynamic response of the aircraft during the automatic flight are investigated, assessing the impact of autopilot configuration, such as altitude-airspeed holding modes and suggesting a setting guideline for flight mode selection compatible with the features of commercial autopilots.
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Aprovitola, Andrea, Oleksandr Dyblenko, Giuseppe Pezzella e Antonio Viviani. "Aerodynamic Analysis of a Supersonic Transport Aircraft at Low and High Speed Flow Conditions". Aerospace 9, n. 8 (29 luglio 2022): 411. http://dx.doi.org/10.3390/aerospace9080411.
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The recent improvement of technology readiness level in aeronautics and the renewed demand for faster transportation are driving the rebirth of supersonic flight for commercial aviation. However, the design of a future supersonic aircraft is still very challenging due to the complexity of several problems, such as static stability performance during the acceleration phase from subsonic speeds to supersonic speeds. Additionally, the interest of scientific community in open source numerical platform as a valid tool for a reliable and affordable aerodynamic design is considerably growing. In this framework, the present work addresses the aerodynamic performance of a Concorde-like aeroshape developed within the preliminary design of a high-speed civil transportation aircraft. Several flight conditions, ranging from subsonic to supersonic speeds, were investigated in detail by using Computational Fluid Dynamics. The aerodynamic force and moment coefficients are computed with fully three-dimensional and steady state Reynolds Average Navier-Stokes simulations, carried out in turbulent flow conditions. The effect of the Mach number variation on the shift of the aircraft aerodynamic center is detailed, by focusing on the aircraft pitching static stability. Flowfield numerical simulations are performed with both commercial (Ansys-Fluent) tool and open-source (SU2) code, which is also used extensively in multidisciplinary design procedures, for further comparisons. Particular attention is focused on the shift of the aeroshape aerodynamic center to verify that the provided wing design allows the aircraft static margin to be within 5% of the reference length, both at low-speed and high-speed flight conditions. The computed positions of the aerodynamic center are in agreement with the aeroshape surface pressure distributions and confirmed the literature results available for the Concorde aircraft. Therefore, in the view of future simulation campaigns for supersonic transportation aircraft, the present work aims to bridge the gap between previous aerodynamic design experiences, for instance matured on Concorde, and those carried out with modern CFD tools on full-scale aircraft, and on time-scales compatible with conceptual design practice. Finally, as the difference between the computed aerodynamic coefficients reflected mainly on drag computation performed with SU2, a special focus on numerical diffusion effect of the solver is also given and compared with a commercial certified CFD tool. This adds a unique further contribution to the SU2 community for aeronautics application.
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Rice, Stephen, e Scott R. Winter. "Which Passenger Emotions Mediate the Relationship Between Type of Pilot Configuration and Willingness to Fly in Commercial Aviation?" Aviation Psychology and Applied Human Factors 5, n. 2 (novembre 2015): 83–92. http://dx.doi.org/10.1027/2192-0923/a000081.
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Abstract. There have been a few studies that have examined how different pilot configurations affect aviation consumer perceptions about trust, comfort, and willingness to fly (e.g., Rice et al., 2014, Int J Aviation, Aeronautics, and Aerospace, 1, 1–12; Winter et al., in press , J Air Transp Management); however, to date, no study was found that has examined how the relationship between pilot configuration and willingness to fly might be mediated by different emotions. The purpose of this study was to fill this gap by examining how affect (emotion) mediates this relationship, and more specifically, which emotion(s) mediate. In two studies, participants were presented with different pilot configurations and asked to rate how they felt about them and how willing they would be to fly under those circumstances. Both studies revealed strong evidence that affect was a mediator in this relationship, and that anger, fear, and happiness were the significant emotions in play. The findings from this study provide information on how consumers view modifying the number of pilots that may be on board the aircraft compared with controlling the aircraft remotely. It also identifies that emotions play a significant role in these relationships.
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Hester, Zack. "After the International Space Station: National Aeronautics and Space Administration, Industry, and the Future of Commercial Spaceflight in Low-Earth Orbit". New Space 5, n. 1 (marzo 2017): 33–44. http://dx.doi.org/10.1089/space.2016.0015.
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Penchev, Radostin, Richard A. Scheuring, Adam T. Soto, Derek M. Miletich, Eric Kerstman e Steven P. Cohen. "Back Pain in Outer Space". Anesthesiology 135, n. 3 (12 maggio 2021): 384–95. http://dx.doi.org/10.1097/aln.0000000000003812.
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Space travel has grown during the past 2 decades, and is expected to surge in the future with the establishment of an American Space Force, businesses specializing in commercial space travel, and National Aeronautics and Space Administration’s planned sustained presence on the moon. Accompanying this rise, treating physicians are bracing for a concomitant increase in space-related medical problems, including back pain. Back pain is highly prevalent in astronauts and space travelers, with most cases being transient and self-limiting (space adaptation back pain). Pathophysiologic changes that affect the spine occur during space travel and may be attributed to microgravity, rapid acceleration and deceleration, and increased radiation. These include a loss of spinal curvature, spinal muscle atrophy, a higher rate of disc herniation, decreased proteoglycan and collagen content in intervertebral discs, and a reduction in bone density that may predispose people to vertebral endplate fractures. In this article, the authors discuss epidemiology, pathophysiology, prevention, treatment, and future research.
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Rose, Nancy L. "Fear of Flying? Economic Analyses of Airline Safety". Journal of Economic Perspectives 6, n. 2 (1 maggio 1992): 75–94. http://dx.doi.org/10.1257/jep.6.2.75.
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The safety of the commercial airline industry has attracted considerable attention in the wake of airline deregulation, amid growing concerns that the historical superiority of U.S. jet carriers' safety records may have been linked to economic regulation of the industry by the Civil Aeronautics Board. These worries have energized economic research on a broad range of questions relating to airline safety. I describe our progress in answering four questions: First, has airline safety declined since deregulation? Second, how has airline deregulation affected the safety of travelers overall, (taking into account indirect channels through which airline deregulation may have changed travel risks, including the substitution of commuter airlines for jet service and the replacement of highway driving by air travel)? Third, what accounts for differences in safety performance across carriers? Fourth, what are the market penalties for airline accidents? (If consumers and insurance companies penalize airlines with worse safety records, carriers may be disinclined to reduce safety investment, even if regulatory changes would permit them to do so.)
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Ackroyd, J. A. D. "The United Kingdom’s contributions to the development of aeronautics. Part 1. From antiquity to the era of the Wrights". Aeronautical Journal 104, n. 1031 (gennaio 2000): 9–30. http://dx.doi.org/10.1017/s0001924000064113.
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The Millennium now being upon us, it is perhaps appropriate to pause a while and take stock before leaping into an ever more problematic future. But why pause? Indeed, why bother with the past? Surely our newest, ever more sophisticated computer packages provide all the necessary paths to that next commercial edge, that future, unassailable military superiority? To this the German polymath, Gottfried Wilhelm von Leibniz, provides an apt, timely and, indeed, timeless corrective: “It is an extremely useful thing to have knowledge of the true origins of memorable discoveries, especially those that have been found not by accident but by dint of meditation. It is not so much that thereby history may attribute to each man his own discoveries and others should be encouraged to earn like commendation, as that the art of making discoveries should be extended by considering noteworthy examples of it.”
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Petersen, Eric, James M. Pattarini, Robert A. Mulcahy, Samuel B. Beger, Matthew R. Mitchell, Yiyuan David Hu, Kathryn N. Middleton et al. "Adapting Disease Prevention Protocols for Human Spaceflight During COVID-19". Aerospace Medicine and Human Performance 92, n. 7 (1 luglio 2021): 597–602. http://dx.doi.org/10.3357/amhp.5832.2021.
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BACKGROUND: The National Aeronautics and Space Administration (NASA) Flight Crew Health Stabilization Program (HSP) was historically implemented to minimize infectious disease transmission to astronauts in the immediate prelaunch period. The first ever commercial application and adaptation of the NASA HSP was implemented during the Crew Demo-2 mission in the time of the Coronavirus disease 2019 (COVID-19) pandemic. This article details and discusses the first commercial implementation and adaptation of the HSP prior to the Crew Demo-2 launch.METHODS: This is a retrospective descriptive analysis of the application of NASA disease prevention protocols for human spaceflight during the COVID-19 pandemic. In the context of the pandemic, extra precautions added to the HSP included daily symptom surveys completed by Primary Contacts of the crew, COVID-19 RT-PCR testing, and improved quarantine protocols.RESULTS: Of the 91 SpaceX Primary Contacts who completed a total of 2720 daily symptom surveys prior to launch, 22 individuals (24.2) and 198 surveys (7.3) returned positive for potential symptoms of COVID-19. Two individuals were removed due to symptoms indistinguishable from COVID-19. Through this survey, systematic quarantine, and PCR testing, the Crew Demo-2 mission was successful with no known infectious diseases transmitted.CONCLUSIONS: Overall, the commercial implementation of the NASA Health Stabilization Program by SpaceX with adjustments required during the COVID-19 pandemic was a success, with protocols allowing identification and removal of potentially infectious persons from the program. The principles of the HSP may provide an adequate infectious disease playbook for commercial spaceflight operations going forward.Petersen E, Pattarini JM, Mulcahy RA, Beger SB, Mitchell MR, Hu YD, Middleton KN, Frazier W, Mormann B, Esparza H, Asadi A, Musk ER, Alter G, Nilles E, Menon AS. Adapting disease prevention protocols for human spaceflight during COVID-19. Aerosp Med Hum Perform. 2021; 92(7):597602.
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Ackroyd, J. A. D. "The United Kingdom’s contributions to the development of aeronautics Part 4. The origins of the jet age". Aeronautical Journal 107, n. 1067 (gennaio 2003): 1–48. http://dx.doi.org/10.1017/s0001924000011787.
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Despite the common title of this series of papers, the specific area into which we now move originated on a more global scale than the title suggests. Thus in the spirit of the plan set down at the outset for this review, viz that major ideas from abroad must be included, contributions from such countries as France, Germany and the United States here warrant greater prominence. In Part 3 of this review we surveyed the development within Britain of the stress-skinned streamlined monoplane. Since the 1920s increasing numbers within Britain’s government research establishments, the universities and industry had been actively promoting this advance. Nonetheless, the practical hardware’s eventual emergence by the mid-1930s was largely driven by industry’s need for greater aerodynamic efficiency and a desire to excel. Thus record-breaking attempts, events such as the Schneider Trophy and MacRobertson races, all provided the impetus for this. So, too, did the commercial pressure of a new generation of American airliners and, for those astute enough to interpret them as such, the alarum calls of an impending Second World War. As a result of the appreciable decrease in drag coefficient achieved, coupled to a massive improvement in piston engine power, military aircraft, in particular, proved capable of flying not only further and higher but also dramatically faster. A further consequence, however, was that certain wartime high-speed fighter aircraft began to encounter serious, even fatal, compressibility effects as their enhanced speeds in dives reached subsonic critical Mach number conditions.
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Malone, John, Robert Bergquist, Moara Martins e Jeffrey Luvall. "Use of Geospatial Surveillance and Response Systems for Vector-Borne Diseases in the Elimination Phase". Tropical Medicine and Infectious Disease 4, n. 1 (18 gennaio 2019): 15. http://dx.doi.org/10.3390/tropicalmed4010015.
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The distribution of diseases caused by vector-borne viruses and parasites are restricted by the environmental requirements of their vectors, but also by the ambient temperature inside the host as it influences the speed of maturation of the infectious agent transferred. The launch of the Soil Moisture Active Passive (SMAP) satellite in 2015, and the new ECOSTRESS instrument onboard the International Space Station (ISS) in 2018, established the leadership of the National Aeronautics Space Administration (NASA) in ecology and climate research by allowing the structural and functional classification of ecosystems that govern vector sustainability. These advances, and the availability of sub-meter resolution data from commercial satellites, contribute to seamless mapping and modelling of diseases, not only at continental scales (1 km2) and local community or agricultural field scales (15–30 m2), but for the first time, also at the habitat–household scale (<1 m2). This communication presents current capabilities that are related to data collection by Earth-observing satellites, and draws attention to the usefulness of geographical information systems (GIS) and modelling for the study of important parasitic diseases.
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Marimuthu, Siva, Samer Al-Rabeei e Hithim Ahmed Boha. "Three-Dimensional Analysis of Biomimetic Aerofoil in Transonic Flow". Biomimetics 7, n. 1 (22 gennaio 2022): 20. http://dx.doi.org/10.3390/biomimetics7010020.
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Since the invention of the aircraft, there has been a need for better surface design to enhance performance. This thirst has driven many aerodynamicists to develop various types of aerofoils. Most researchers have strongly assumed that smooth surfaces would be more suitable for air transport vehicles. This ideology was shattered into pieces when biomimetics was introduced. Biomimetics emphasized the roughness of a surface instead of smoothness in a fluid flow regime. In this research, the most popular 0012 aerofoils of the National Advisory Committee for Aeronautics (NACA) are considered to improve them, with the help of a surface pattern derived from the biological environment. Original and biomimetic aerofoils were designed in three dimensions with the help of Solidworks software and analyzed in the computational flow domain using the commercial code ANSYS Fluent. The implemented biomimetic rough surface pattern upgraded the NACA 0012 aerofoil design in the transonic flow regime. Lift and viscous forces of the aerofoil improved up to 5.41% and 9.98%, respectively. This research has proved that a surface with a little roughness is better than a smooth surface.
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Litaker, Harry, Omar Bekdash, Steve Chappell, Kara Beaton e Michael Gernhardt. "Understanding Human Movement Patterns within Cislunar Habitats". Proceedings of the Human Factors and Ergonomics Society Annual Meeting 64, n. 1 (dicembre 2020): 1208–12. http://dx.doi.org/10.1177/1071181320641288.
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In preparation for testing five Broad Agency Announcement (BAA) commercial cislunar habitat designs, the National Aeronautics and Space Administration (NASA) embarked on a yearlong in-house training program. This consisted of in-house testing for subject matter experts (SMEs) and crew to informed and ensure evaluation data collection techniques for each of the contractor options. Many evaluation techniques were tested with some continuing forward. Two-test conditions were employed - 1) habitat centric functions with one space element and 2) distributed functions across two or more space elements. This paper will look at one of these techniques—human circulation patterns—to assess a spacecraft habitat’s internal configuration while the crew is working a three day simulated cislunar mission. Real time tracking of the crew was accomplished using the AllTraq© system of ultra- wideband frequency (UWB) receivers and radio frequency identification tags (RFID). Heat maps, Zone Time Histograms, Zone Time Utilizations Tables and Task/Time Density Tables were constructed from the collected data. Results indicated distributing functions across elements decreased crew interference and task wait times. Additionally, areas of underutilization were located, which lead to interior layout design changes.
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Kwan, Chiman, Bryan Chou e James Bell III. "Comparison of Deep Learning and Conventional Demosaicing Algorithms for Mastcam Images". Electronics 8, n. 3 (11 marzo 2019): 308. http://dx.doi.org/10.3390/electronics8030308.
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Bayer pattern filters have been used in many commercial digital cameras. In National Aeronautics and Space Administration’s (NASA) mast camera (Mastcam) imaging system, onboard the Mars Science Laboratory (MSL) rover Curiosity, a Bayer pattern filter is being used to capture the RGB (red, green, and blue) color of scenes on Mars. The Mastcam has two cameras: left and right. The right camera has three times better resolution than that of the left. It is well known that demosaicing introduces color and zipper artifacts. Here, we present a comparative study of demosaicing results using conventional and deep learning algorithms. Sixteen left and 15 right Mastcam images were used in our experiments. Due to a lack of ground truth images for Mastcam data from Mars, we compared the various algorithms using a blind image quality assessment model. It was observed that no one algorithm can work the best for all images. In particular, a deep learning-based algorithm worked the best for the right Mastcam images and a conventional algorithm achieved the best results for the left Mastcam images. Moreover, subjective evaluation of five demosaiced Mastcam images was also used to compare the various algorithms.
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Sohn, Jung Min, Spyros Hirdaris, Jani Romanoff e Sang Jin Kim. "Development of Numerical Modelling Techniques for Composite Cylindrical Structures under External Pressure". Journal of Marine Science and Engineering 10, n. 4 (25 marzo 2022): 466. http://dx.doi.org/10.3390/jmse10040466.
Testo completoAbstract (sommario):
Submarine hulls are pressure vessels for which excellent structural integrity under underwater pressure loads is essential. The use of light-weight materials contributes to reduced fuel consumption, improved speed, and increased payload while strength properties are retained. The focus of this paper is on the collapse behavior of a filament-wound cylindrical structure that serves as the main hull of a submarine subject to hydrostatic pressure loads. This paper presents a computational modelling approach for the prediction of the collapse behavior mechanism using a commercial finite element (FE) solver. The collapse strength obtained from the numerical model corresponded closely to available experimental data. The composite and aluminum material models were compared and the effects of stacking angle and thickness portion in the ply sequence on collapse strength were investigated. The advantages and disadvantages of available design codes (i.e., American Society of Mechanical Engineers (ASME) BPVC-X and National Aeronautics and Space Administration (NASA) SP-8007) were reviewed by direct comparison with numerical results. It is concluded that the application of effective engineering constants for the prediction of the collapse pressure of submarine hulls may be feasible.
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HOOGE, SOPHIE, MATHIAS BÉJEAN e FRÉDÉRIC ARNOUX. "ORGANISING FOR RADICAL INNOVATION: THE BENEFITS OF THE INTERPLAY BETWEEN COGNITIVE AND ORGANISATIONAL PROCESSES IN KCP WORKSHOPS". International Journal of Innovation Management 20, n. 04 (maggio 2016): 1640004. http://dx.doi.org/10.1142/s1363919616400041.
Testo completoAbstract (sommario):
In several industries, competitive and societal factors have highlighted the need for incubating dedicated radical innovation (RI) capabilities. Traditional approaches to RI strategies have often emphasised either organisational or cognitive aspects, but tend to overlook how these dimensions interact within the organisation. This paper tackles the issue of these interplays by investigating the effects of a creativity-based collaborative method, the KCP Workshops, on the RI capability of a firm. We present an in-depth case study of a leading aeronautics firm that adopted the method to face its RI challenges. While being consistent with prior research and underscoring the impact of organisational settings on creative cognitive processes, our analysis empirically demonstrates a triple capability developed through the KCP Workshops: (1) collectively building a conceivable RI strategy, (2) deploying a monitoring process adapted to the exploration of cognitive breakthroughs, (3) collectively building “emerging creative organisations” at the ecosystem level to support the development of RI strategy. Beyond the performance of the RI capability for commercial applications, these findings underline how the collective design of an RI strategy also involves players in the exploration and establishment of organisational innovations.
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Carr, Alexander N., Joel B. Lonzaga e Steven A. Miller. "Split-step simulations of sonic boom propagation beyond the lateral cutoff in a turbulent atmosphere". Journal of the Acoustical Society of America 152, n. 4 (ottobre 2022): A80. http://dx.doi.org/10.1121/10.0015611.
Testo completoAbstract (sommario):
Recent flight tests during the Quiet Supersonic Flights 2018 (QSF18) study reported sonic booms heard outside of the primary carpet region. In the absence of turbulence, the lateral cutoff region separates the primary sonic boom carpet from the shadow zone, where the sonic boom signal experiences significant attenuation. However, when turbulence is present in the atmospheric boundary layer (ABL), additional scattering of the sonic boom to the shadow zone region occurs. A method is presented for simulating sonic boom propagation in a turbulent atmospheric boundary layer beyond the lateral cutoff region into the shadow zone. A split-step method is used to integrate a partially one-way equation for the acoustic pressure. Inhomogeneous turbulence, representative of the ABL, is generated in the computational domain with a Fourier synthesis approach. Distributions of several loudness metrics in the shadow zone region for a sonic boom N-wave and a shaped boom are examined. Increasing both turbulence root-mean-square velocity and integral length scale are found to increase the average loudness of booms in the shadow zone. (This research is supported by the Commercial Supersonic Technology Project of the National Aeronautics and Space Administration under Grant No. 80NSSC19K1685.)
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Carr, Alexander N., Joel B. Lonzaga e Steven A. Miller. "Nonnormality of sonic boom loudness metrics in the turbulent atmospheric boundary layer at large lateral distances from the flight path". Journal of the Acoustical Society of America 152, n. 4 (ottobre 2022): A126. http://dx.doi.org/10.1121/10.0015768.
Testo completoAbstract (sommario):
Atmospheric boundary layer (ABL) turbulence causes variability of the sonic boom waveform at the ground. Recent numerical investigations of sonic boom propagation through kinematic velocity fluctuations indicate that loudness metric distributions are positively skewed relative to a normal distribution. This skewness depends on the propagation distance and turbulence intensity. Propagation simulations of N-waves and shaped booms through inhomogeneous ABL turbulence are presented. Meteorological conditions are varied to examine different daytime ABL conditions and their effect on sonic boom loudness distributions. Two outcomes are observed: (1) the loudness metric distributions become increasingly positively skewed as the propagation distance through the ABL increases, and (2) the distributions become increasingly positively skewed at the same lateral distance from the flight path as the convection level of the daytime ABL is increased. Thus, results indicate that ground level measurements of sonic boom loudness from flight tests performed at large lateral distances from the flight path may not be normally distributed, due to turbulence present in the ABL. (This research is supported by the Commercial Supersonic Technology Project of the National Aeronautics and Space Administration under Grant No. 80NSSC19K1685.)
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Rizzi, Stephen A., e Donald S. Scata, Jr. "Urban air mobility community noise test planning". Journal of the Acoustical Society of America 152, n. 4 (ottobre 2022): A84. http://dx.doi.org/10.1121/10.0015626.
Testo completoAbstract (sommario):
The term “advanced air mobility” has been adopted by NASA to describe safe, sustainable, affordable, and accessible aviation for transformational local and intraregional missions. By this definition, advanced air mobility includes both “rural” and “urban” applications including cargo and passenger transport missions, and other aerial missions (e.g., infrastructure inspection). There will be a range of aircraft types performing such missions, including small and medium unmanned aircraft systems (UAS), electric conventional takeoff and landing (eCTOL) aircraft, and electric vertical takeoff and landing (eVTOL) aircraft. Urban air mobility (UAM) is a challenging use case for transporting cargo and passengers in an urban environment and is a new opportunity for aviation that could revolutionize the transportation system. The National Aeronautics and Space Administration and the Noise Division of the Federal Aviation Administration Office of Environment and Energy have initiated discussions for planning UAM community noise test(s) at the end of this decade. This presentation discusses the test goals, candidate test objectives, and some of the activities needed in preparation for the test(s). It also draws distinctions between the type of study envisioned (observational versus staged) and between it and recent and planned studies on large fixed-wing transports and commercial supersonic transports.
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Linsenmaier, Bernd, e Oliver Straeter. "Recording and Evaluation of Human Factor Events with a View to System Awareness and Ergonomic Weak Points within the System, at the Example of Commercial Aeronautics". Proceedings of the Human Factors and Ergonomics Society Annual Meeting 44, n. 22 (luglio 2000): 835–38. http://dx.doi.org/10.1177/154193120004402288.
Testo completoAbstract (sommario):
The risk for human errors is particularly high, if a person has not considered enough information about his situation. This consideration of information also can be described as situation awareness. It will become dangerous, if a person assesses his awareness higher as it is actual. This discrepancy between subjective and actual situation awareness can be found out at almost all Human Factor (HF) Events. With the examination of the situation awareness, the event analysis is carried out consistently from the point of view of the man. By this concept, HF Events can be examined even more on ergonomic aspects. It is however necessary that reports about HF Events provide sufficient information about the situation awareness. For this a computer-based event analysis scheme is used to report events interactively. With this software, we currently investigate how it is possible to create uniform and comparable event reports. The complete event is divided up into sub-events and is described using the Man Machine System framework. The demarcation of the sub-events is mainly made by allocation of the persons involved. This human and system related view also allows describing the situation awareness of this person and provides data for the later analysis of the situation awareness.
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De Cássia Godoi Moraes, Lívia. "NAS ASAS DO CAPITAL: EMBRAER, financeirização e implicações sobre os trabalhadores". Caderno CRH 30, n. 79 (22 settembre 2017): 13–31. http://dx.doi.org/10.9771/ccrh.v30i79.19925.
Testo completoAbstract (sommario):
O objeto de análise deste artigo é o processo de crescente financeirização na empresa líder em aeronáutica no Brasil, a EMBRAER – Empresa Brasileira de Aeronáutica S.A, hoje, apenas EMBRAER S.A –, e os impactos sobre seus trabalhadores diretos e indiretos. A EMBRAER é a terceira maior produtora de aviões comerciais do mundo, cujo patamar de concorrência a faz primar por tendências organizacionais hegemônicas em âmbito mundial. A investigação, centrada em análise de conteúdo, a partir de documentos oficiais e pesquisas científicas até então publicadas, constatou quatro principais momentos de imbricação entre capital produtivo e capital fictício desde a sua privatização, em 1994, até o ano de 2012, quando se encerra a pesquisa: 1) a partir da década de 1990, quando a empresa foi privatizada; 2) de forma mais determinante, no início dos anos 2000, com a produção de aviões comerciais da família EMBRAER 170/190; 3) com a posterior pulverização de capitais, em 2006; e, por fim, 4) na mudança de razão social para fins de ampliação de áreas de atuação da empresa, em 2010. O contexto em que se dão tais mudanças é o de mundialização do capital e prevalência de acumulação fictícia de capital, com fortes impactos sobre intensificação do uso da força de trabalho. ABSTRACTThe object of analysis in this article is the process of increasing financialization in the leading aeronautics company in Brazil, Brazilian Aeronautics Company S.A, (nowadays, only called EMBRAER S.A), and the impact on their direct and indirect workers. EMBRAER is the third biggest manufacturer of commercial airplanes in the world; thus, the level of competition makes the company privilege hegemonic organizational trends of global level. This investigation, centered on content analysis from official documents and scientific research published until then, verified four main moments of interconnections between productive capital and fictitious capital since its privatization in 1994, until 2012 when the research was finished. Thus, four moments come to light: 1) the 1990s, when the company was privatized; 2) in a determinant way, the beginning of the 2000’s with the manufacture of commercial airplanes EMBRAER 170/190; 3) the posterior pulverization of capital in 2006; and, finally, 4) the change of the corporate name for the purpose of expanding the areas of activity of the company in 2010. The context of such changes is that of the globalization of capital and the predominance of fictitious accumulation of capital with strong impacts in the intensification of workforce use.Key words: Financialization; Work; EMBRAER; Restauration; Productive; ExplorationABSTRACTLe sujet de cet article est le processus de financiarisation croissante dans l’entreprise leuder de l’industrie d’aviation brésilienne, EMBRAER – Entreprise Brésilienne d’Aéronautique S.A, aujourd’hui, seulement EMBRAER S.A –, et ses concéquences sur le travail et ses travailleurs directs et indirects. L’EMBRAER est la troisième plus grande productrice d’avions commerciaux du monde, dont le niveau de la concurrence l’induit a donner la priorité à des tendances organisationnelles hégémoniques dans le contexte mondial. La recherche, concentrée sur l’analyse de contenu, à partir des documents officiels et des recherches scientifiques jusqu’à ce moment publiées, a identifié quatre principaux moments de forte chevauchement entre capital fictif et capital productif depuis sa privatisation, en 1994, jusqu’à l’année de 2012, quand quand la recherche se ferme: 1) à partir de 1994, quand l’entreprise a été privatisé ; 2) De façon déterminante, dans le début des années 2000, avec la production des avions commerciaux de la famille EMBRAER 170/190 ; 3) avec la subséquent pulvérisation des capitaux, en 2006; et, enfin, 4) aprés le changement de la dénomination sociale dont l’objectif était élargir les zones d’opération de l’entreprise, en 2010. Le contexte dans lequel ces changements se produisent est la mondialisation du capital avec la prévalence de l’accumulation de capital fictif , qui a des forts impacts sur l’utilisation intensifiée de la main-d’œuvre.Key words: Financiarisation; Travail; EMBRAER; Restructuration Productive; Exploration
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Hamrick, Joseph T. "A Review of the History of the National Advisory Committee for Aeronautics Centrifugal Compressor Program and Arrival at Current Computational Design Procedures". Journal of Fluids Engineering 127, n. 1 (1 gennaio 2005): 94–97. http://dx.doi.org/10.1115/1.1855326.
Testo completoAbstract (sommario):
Before and during World War II, the design and development of single stage high pressure ratio centrifugal compressors was essentially a cut-and-try exercise. To reach a high pressure without substantial experimentation required multiple stages of impellers and diffusers with pressure ratios in the 2:1 range. While such arrangements were satisfactory for commercial use where weight was not a major consideration, they were not suitable for jet engines. The centrifugal compressor for the Whittle engine, the first British jet engine, was developed by trial and error with numerous modifications of the hub-shroud profile. The centrifugal compressor section of the National Advisory Committee for Aeronautics (NACA) designed, built, and tested three compressor impellers during and after World War II. They were part of a program designed to evaluate various blade shapes, but encountered such instabilities at the design pressure ratios that the experimental results led to no definitive conclusions. In 1948, the Centrifugal Compressor Section was given the assignment to further investigate the three impellers. The investigation led to the development of a quasi-three-dimensional design procedure that eliminated the guesswork from the basic design of a centrifugal impeller. Since the 1948 to 1955 time period over which the procedure was developed, the advances in computers have allowed refinements in the original computational methods. It is the objective of this presentation to review the history of the NACA centrifugal compressor program and efforts that have led to the latest developments in computational design procedures.
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Lahvis, Abigail. "Remaining Human: How the Airline Deregulation Act Shields Commercial Air Carriers From Legal Liability for Mishandling Human Remains". Journal of Air Law and Commerce 87, n. 4 (2022): 799. http://dx.doi.org/10.25172/jalc.87.4.5.
Testo completoAbstract (sommario):
The Airline Deregulation Act of 1978 (ADA) deregulated the domestic airline industry. Specifically, the ADA ended the dual administrative system, which allowed the states to regulate intrastate airfare and permitted the federal government’s Civil Aeronautics Board (CAB) to regulate interstate airfare. The Act also included a broad preemption clause to prevent the states from reimposing economic regulations on air travel. The preemption clause prohibits a “State . . . [from] enact[ing] or enforc[ing] any law, rule, regulation, standard, or other provision having the force and effect of law relating to rates, routes, or services of any air carrier.” The Supreme Court has interpreted the scope of the ADA’s preemption clause expansively and concluded that only state law claims with a “tenuous, remote, or peripheral” relationship to an airline’s services survive preemption. Yet, the Supreme Court has never defined the key word: Service. Today, federal circuit courts disagree on the definition of “service,” and a majority have adopted the Fifth Circuit’s definition articulated in Hodges v. Delta Airlines, Inc. Applying the Supreme Court’s expansive view of the ADA’s preemption clause, the Fifth Circuit defined the term “service” as all bargained-for air carrier services, including “ticketing, boarding procedures, provision of food and drink, and baggage handling, in addition to the transportation itself.” The Fifth Circuit’s definition preempts almost all conceivable state law claims despite the Supreme Court excepting claims with a “tenuous, remote, or peripheral” relationship to an airline’s services from preemption. Consequently, the aviation industry largely evades state law. This Comment argues that courts should interpret the ADA’s preemption clause more narrowly to allow more state law claims to survive preemption, particularly claims arising from an airline’s mishandling, delaying, or misplacing of a loved one’s remains. As the COVID-19 pandemic claims lives and frustrates air travel, a perfect storm threatens to mishandle, delay, or misplace a loved one’s remains. Grieving mothers, fathers, husbands, and wives are left without a legal remedy because the ADA shields the airline industry from liability concerning “baggage handling” and the “transportation itself.” Courts should interpret the ADA’s preemption clause more narrowly based on the ADA’s clear purpose, the plain meaning of the ADA’s text, stare decisis, and the law’s treatment of other entities that mishandle human remains.
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Ferreira-Snyman, Anél, e Gerrit M. Ferreira. "The Application of International Human Rights Instruments in Outer Space Settlements: Today's Science Fiction, Tomorrow's Reality". Potchefstroom Electronic Law Journal 22 (25 giugno 2019): 1–43. http://dx.doi.org/10.17159/1727-3781/2019/v22i0a5904.
Testo completoAbstract (sommario):
The military and commercial exploitation of outer space has received increasing international attention since the United States of America announced its intention to establish an outer space military force to protect its interests in outer space. Simultaneously, the National Aeronautics and Space Administration (NASA) and private enterprises such as Blue Origin and SpaceX declared plans to colonise the Moon and/or Mars in the near future. While technology is advancing rapidly to make these objectives a reality, the international legal rules related to these developments are completely uncertain, and in some instances non-existent. It is evident that these developments may have a direct impact on the internationally protected human rights of individuals, taking into account the extremely adverse conditions in outer space and the dangers involved in creating sustainable human living conditions in outer space. International discussion of and action on these legal issues are needed urgently. As a starting point, this contribution discusses the question of whether existing international human rights instruments enjoy extra-territorial application in outer space, given the current status of outer space law. In answering the question, a broad overview is presented of some human rights issues that may be relevant to living in outer space, and the role that the doctrine of effective control may play in this regard is analysed.
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Ren, Guanghao, Yun Wang, Zhenyun Shi, Guigang Zhang, Feng Jin e Jian Wang. "Aero-Engine Remaining Useful Life Estimation Based on CAE-TCN Neural Networks". Applied Sciences 13, n. 1 (20 dicembre 2022): 17. http://dx.doi.org/10.3390/app13010017.
Testo completoAbstract (sommario):
With the rapid growth of the aviation fields, the remaining useful life (RUL) estimation of aero-engine has become the focus of the industry. Due to the shortage of existing prediction methods, life prediction is stuck in a bottleneck. Aiming at the low efficiency of traditional estimation algorithms, a more efficient neural network is proposed by using Convolutional Neural Networks (CNN) to replace Long-Short Term Memory (LSTM). Firstly, multi-sensor degenerate information fusion coding is realized with the convolutional autoencoder (CAE). Then, the temporal convolutional network (TCN) is applied to achieve efficient prediction with the obtained degradation code. It does not depend on the iteration along time, but learning the causality through a mask. Moreover, the data processing is improved to further improve the application efficiency of the algorithm. ExtraTreesClassifier is applied to recognize when the failure first develops. This step can not only assist labelling, but also realize feature filtering combined with tree model interpretation. For multiple operation conditions, new features are clustered by K-means++ to encode historical condition information. Finally, an experiment is carried out to evaluate the effectiveness on the Commercial Modular Aero-Propulsion System Simulation (CMAPSS) datasets provided by the National Aeronautics and Space Administration (NASA). The results show that the proposed algorithm can ensure high-precision prediction and effectively improve the efficiency.
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Godines, Cody, Saber DorMohammadi, Frank Abdi, Marc Villa Montero, Dade Huang e Levon Minnetyan. "Damage tolerant composite design principles for aircraft components under static service loading using multi-scale progressive failure analysis". Journal of Composite Materials 51, n. 10 (22 novembre 2016): 1393–419. http://dx.doi.org/10.1177/0021998316671575.
Testo completoAbstract (sommario):
The overall objective of this effort was to provide theoretical prediction for damage development for a set of laminated composites using Alpha STAR Corporations’ commercial code GENOA (GENeral Optimization Analyzer) for the Air Force Research Laboratory program entitled “Damage Tolerance Design Principles (DTDP)”. Damage progression and prediction for advance composite benchmarks were done under static and fatigue service loading using test data from Lockheed Martin Aeronautics and Air Force Research Laboratory. In the current paper, the results for the static analysis are presented. Emerging and innovative multi-scale (MS) modeling using computational structural mechanics and progressive failure analysis were proven to address the Air Force’s vision to perform predictive evaluation of composite materials using a building block validation strategy and certification process. Three layups were tested in tension and compression for unnotched and openhole configurations. Calibration of the fiber and matrix properties was performed using in plane, 3pt bend and DCB test data. After this, mesh convergence, solver selection based on CPU time, and mesh sensitivities was performed. The static blind simulations of strength showed an average error of 12.9% between simulation and the test data. For stiffness, the percent difference was found to be 23.5% on average. Although the focus was on the ability to blindly predict test data, recalibration efforts show an average of 9.2% difference between simulation and test for strengths and 12.4% for stiffness computations. Damage at ∼60–75% and ∼90% of max loading was comparable with X-ray observations of specimens set aside solely for that purpose. All simulations used the same set of inputs (constituents, voids, fiber waviness, etc.) except for the noted analysis setting differences between blind and recalibration simulations. The method is consistent and follows a building block simulation approach that has an advanced yet simplistic theoretical multi-scale progressive failure analysis approach all contained in the commercial GENOA software. The method was demonstrated to work having GENOA directly run sequential NASTRAN simulations and, post project completion, with the ABAQUS solver using GENOA as a material subroutine.
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Nowadly, Craig D., Brandon D. Trapp, Stephen K. Robinson e John R. Richards. "Resuscitation and Evacuation from Low Earth Orbit: A Systematic Review". Prehospital and Disaster Medicine 34, n. 05 (29 agosto 2019): 521–31. http://dx.doi.org/10.1017/s1049023x19004734.
Testo completoAbstract (sommario):
AbstractIntroduction:Provision of critical care and resuscitation was not practical during early missions into space. Given likely advancements in commercial spaceflight and increased human presence in low Earth orbit (LEO) in the coming decades, development of these capabilities should be considered as the likelihood of emergent medical evacuation increases.Methods:PubMed, Web of Science, Google Scholar, National Aeronautics and Space Administration (NASA) Technical Server, and Defense Technical Information Center were searched from inception to December 2018. Articles specifically addressing critical care and resuscitation during emergency medical evacuation from LEO were selected. Evidence was graded using Oxford Centre for Evidence-Based Medicine guidelines.Results:The search resulted in 109 articles included in the review with a total of 2,177 subjects. There were two Level I systematic reviews, 33 Level II prospective studies with 647 subjects, seven Level III retrospective studies with 1,455 subjects, and two Level IV case series with four subjects. There were two Level V case reports and 63 pertinent review articles.Discussion:The development of a medical evacuation capability is an important consideration for future missions. This review revealed potential hurdles in the design of a dedicated LEO evacuation spacecraft. The ability to provide critical care and resuscitation during transport is likely to be limited by mass, volume, cost, and re-entry forces. Stabilization and treatment of the patient should be performed prior to departure, if possible, and emphasis should be on a rapid and safe return to Earth for definitive care.
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Mei, Lei, Junwei Zhou, Dong Yu Weichao Shi, Xiaoyun Pan e Mingyang Li. "Parametric Analysis for Underwater Flapping Foil Propulsor". Water 13, n. 15 (31 luglio 2021): 2103. http://dx.doi.org/10.3390/w13152103.
Testo completoAbstract (sommario):
This paper researched into the harmonic and anharmonic underwater flapping foil propulsion systems to improve the efficiency of these bioinspired propulsors. The angle of attack, the pitching angle, the heaving amplitude, and the phase difference are parametrically investigated in this paper. A rigid two-dimensional NACA (National Advisory Committee for Aeronautics) 0012 airfoil is modeled with the aid of a commercial computational fluid dynamics software, FINE™/Marine. Unsteady Reynolds Average Navier-Stokes (URANS) equation is solved together with dynamic mesh to simulate the foil motion. The investigation first verifies the reliability of the developed modeling method against the benchmark data. Then, the systematic investigation is conducted and identifies that the heaving amplitude is most influential factor for the propulsion efficiency. Secondly, phase difference also has a significant influence on efficiency, but this effect is related to the reference working condition, which needs further study. Then, the pitching amplitude has little effect on the maximum efficiency value of flapping foil, while it will affect its optimal speed range. When the heaving amplitude ratio reaches 3 and the corresponding maximum angle of attack is about 9°, the maximum efficiency can reach 87%. The effect of anharmonic motion on the efficiency is very small and varies with the St number, but in summary, it can maintain the peak efficiency over a wider range of operations. In addition, the force and flow field characteristics of different efficiency points are compared and analyzed to distinguish their corresponding relationship with the propulsion efficiency.
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Iiames, John S., Russell Congalton, Andrew Pilant e Timothy Lewis. "Validation of an Integrated Estimation of Loblolly Pine (Pinus taeda L.) Leaf Area Index (LAI) Using Two Indirect Optical Methods in the Southeastern United States". Southern Journal of Applied Forestry 32, n. 3 (1 agosto 2008): 101–10. http://dx.doi.org/10.1093/sjaf/32.3.101.
Testo completoAbstract (sommario):
Abstract Quality assessment of satellite-derived leaf area index (LAI) products requires appropriate ground measurements for validation. Since the National Aeronautics and Space Administration launch of Terra (1999) and Aqua (2001), 1-km, 8-day composited retrievals of LAI have been produced for six biome classes worldwide. The evergreen needle leaf biome has been examined at numerous validation sites, but the dominant commercial species in the southeastern United States, loblolly pine (Pinus taeda), has not been investigated. The objective of this research was to evaluate an in situ optical LAI estimation technique combining measurements from the Tracing Radiation and Architecture of Canopies (TRAC) optical sensor and digital hemispherical photography (DHP) in the southeastern US P.taeda forests. Stand-level LAI estimated from allometric regression equations developed from whole-tree harvest data were compared to TRAC–DHP optical LAI estimates at a study site located in the North Carolina Sandhills Region. Within-shoot clumping, (i.e., the needle-to-shoot area ratio [γE]) was estimated at 1.21 and fell within the range of previously reported values for coniferous species (1.2–2.1). The woody-to-total area ratio (α = 0.31) was within the range of other published results (0.11–0.34). Overall, the indirect optical TRAC–DHP method of determining LAI was similar to LAI estimates that had been derived from allometric equations from whole-tree harvests. The TRAC–DHP yielded a value 0.14 LAI units below that retrieved from stand-level whole-tree harvest allometric equations. DHP alone yielded the best LAI estimate, a 0.04 LAI unit differential compared with the same allometrically derived LAI.
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Krittanawong, Chayakrit, Nitin Kumar Singh, Richard A. Scheuring, Emmanuel Urquieta, Eric M. Bershad, Timothy R. Macaulay, Scott Kaplin et al. "Human Health during Space Travel: State-of-the-Art Review". Cells 12, n. 1 (22 dicembre 2022): 40. http://dx.doi.org/10.3390/cells12010040.
Testo completoAbstract (sommario):
The field of human space travel is in the midst of a dramatic revolution. Upcoming missions are looking to push the boundaries of space travel, with plans to travel for longer distances and durations than ever before. Both the National Aeronautics and Space Administration (NASA) and several commercial space companies (e.g., Blue Origin, SpaceX, Virgin Galactic) have already started the process of preparing for long-distance, long-duration space exploration and currently plan to explore inner solar planets (e.g., Mars) by the 2030s. With the emergence of space tourism, space travel has materialized as a potential new, exciting frontier of business, hospitality, medicine, and technology in the coming years. However, current evidence regarding human health in space is very limited, particularly pertaining to short-term and long-term space travel. This review synthesizes developments across the continuum of space health including prior studies and unpublished data from NASA related to each individual organ system, and medical screening prior to space travel. We categorized the extraterrestrial environment into exogenous (e.g., space radiation and microgravity) and endogenous processes (e.g., alteration of humans’ natural circadian rhythm and mental health due to confinement, isolation, immobilization, and lack of social interaction) and their various effects on human health. The aim of this review is to explore the potential health challenges associated with space travel and how they may be overcome in order to enable new paradigms for space health, as well as the use of emerging Artificial Intelligence based (AI) technology to propel future space health research.
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Abeyratne, Ruwantissa. "Aviation Cyber Security: A Constructive Look at the Work of ICAO". Air and Space Law 41, Issue 1 (1 febbraio 2016): 25–39. http://dx.doi.org/10.54648/aila2016003.
Testo completoAbstract (sommario):
The Economist of 4 November 2014 speaks of ‘cyberjacking’ – a phenomenon that refers to the equivalent of hijacking an aircraft with the use of cyber technology. This could happen from outside the aircraft or from the inside. The catalyst in this instance is the increasing popularity with passengers of internet connectivity on board for work, games, movies et al. The article also mentions that internet signals are routed through existing communications architecture, such as the Aircraft Communications Addressing and Reporting System (ACARS), or the Automatic Dependent Surveillance-Broadcast (ADS-B), which is an anti-collision system, which, both being information communications systems can, in theory be targets of cyber-attacks. In its later edition of 21 May 2015 the same journal highlighted that a hacker had identified a weakness with the in-flight entertainment (IFE) systems on Boeing 737-800, 737-900, 757-200 and Airbus A320 aircraft. He had demonstrated this fact by accessing the systems by plugging a laptop into one of the electronic boxes usually found under the seats either side of the aisle. Once connected, the hacker claims to have accessed other systems on the aircraft. None of these claims have been validated by the scientific community nor have they been put into practice by terrorists or criminals against civil air transport. Nonetheless, this may be a sign of things to come, particularly when one considers that the National Aeronautics and Space Administration’s computers have been hacked in the past and that all computer systems of SONY were hacked in the recent past, allegedly by a foreign State sponsored hacking exercise. As this article discusses, there has been at least one confirmed cyber-attack on a computer system of a commercial airline. The International Civil Aviation Organization(ICAO) has been active in the field of prevention of cyber terrorism, which this article will elaborate on, with some constructive suggestions.
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Sámano-Robles, Ramiro, Tomas Nordström, Kristina Kunert, Salvador Santonja-Climent, Mikko Himanka, Markus Liuska, Michael Karner e Eduardo Tovar. "The DEWI High-Level Architecture: Wireless Sensor Networks in Industrial Applications". Technologies 9, n. 4 (9 dicembre 2021): 99. http://dx.doi.org/10.3390/technologies9040099.
Testo completoAbstract (sommario):
This paper presents the High-Level Architecture (HLA) of the European research project DEWI (Dependable Embedded Wireless Infrastructure). The objective of this HLA is to serve as a reference framework for the development of industrial Wireless Sensor and Actuator Networks (WSANs) based on the concept of the DEWI Bubble. The DEWI Bubble constitutes a set of architecture design rules and recommendations that can be used to integrate legacy industrial sensor networks with a modern, interoperable and flexible IoT (Internet-of-Things) infrastructure. The DEWI Bubble can be regarded as a high-level abstraction of an industrial WSAN with enhanced interoperability (via standardized interfaces), dependability, technology reusability and cross-domain development. The DEWI Bubble aims to resolve the issue on how to integrate commercial WSAN technology to match the dependability, interoperability and high criticality needs of industrial domains. This paper details the criteria used to design the HLA and the organization of the infrastructure internal and external to the DEWI Bubble. The description includes the different perspectives, models, or views of the architecture: the entity model, the layered perspective of the entity model and the functional model. This includes an overview of software and hardware interfaces. The DEWI HLA constitutes an extension of the ISO/IEC 29182 SNRA (Sensor Network Reference Architecture) towards the support of wireless industrial applications in different domains: aeronautics, automotive, railway and building. To improve interoperability with existing approaches, the DEWI HLA also reuses some features from other standardized technologies and architectures. The DEWI HLA and the concept of Bubble allow networks with different industrial sensor technologies to exchange information between them or with external clients via standard interfaces, thus providing consolidated access to sensor information of different industrial domains. This is an important aspect for smart city applications, Big Data, Industry 4.0 and the Internet-of-Things (IoT). The paper includes a non-exhaustive review of the state of the art of the different interfaces, protocols and standards of this architecture. The HLA has also been proposed as the basis of the European projects SCOTT (Secure Connected Trustable Things) for enhanced security and privacy in the IoT and InSecTT (Intelligent Secure Trustable Things) for the convergence of artificial intelligence (AI) and the IoT.
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Ort, Markus. "Displays in air traffic control". Information Design Journal 11, n. 1 (26 settembre 2003): 17–31. http://dx.doi.org/10.1075/idj.11.1.04ort.
Testo completoAbstract (sommario):
Commercial aviation is becoming more and more important these days. From year to year there is an accelerated increase in the density of air traffic. The resulting fast growth in the flow of data between controllers and the technical systems they use, as well as that between controller and pilot, calls for new means of communication and visualization of information and interaction with it. Revised concepts for air traffic control must be applied, to deal safely with the increasing volume of traffic in the future. The main focus must be on designing an appropriate interface to support the interaction between ground and cockpit, making the communication as efficient, convenient and secure as possible. This undoubtedly goes further than just making information accessible in a digital format. Despite the importance and complexity of the subject, interdisciplinary projects to achieve this were launched only recently. However, as time goes on, more ergonomics specialists, psychologists and designers are working in this field dominated by engineers and programmers. So far, only a few cooperative projects have been undertaken between information designers, interaction designers and air traffic control specialists to create new interface solutions. This is all the more surprising since the structuring and visualization of this immense flow of data, the mapping of dynamic processes and the search for new means of communication constitute a highly interesting field. There is a strong belief that only such cooperation can lead to a coherent product, if interfaces are to be developed which can unfold the potential of the new Datalink-technology. The project described in this article was undertaken at the Design Department of the University of Applied Sciences Cologne, in cooperation with engineers from the Berlin University of Technology/ Institute of Aeronautics and Astronautics/ Section Flight Guidance and Transportation and IT-specialists and air traffic controllers from Skyguide (Zürich and Geneva). After a brief summary of the general situation in air traffic control and the work that controllers do, my aim in this article is to present a feasible interface solution for the arrival/departure sector, one of the most crucial areas of air traffic control.
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Haque, Jamal, M. Erturk, Huseyin Arslan e Wilfrido Moreno. "Cognitive Aeronautical Communication System". International Journal of Interdisciplinary Telecommunications and Networking 3, n. 1 (gennaio 2011): 20–35. http://dx.doi.org/10.4018/jitn.2011010102.
Testo completoAbstract (sommario):
The paper explores the system and architecture requirements for cognitive driven reconfigurable hardware for an aeronautical platform, such as commercial aircraft or high altitude platforms. With advances in components and processing hardware, mobile platforms are ideal candidates to have configurable hardware that can morph itself, given the location and available wireless service. This paper proposes a system for an intelligent self-configurable software and hardware solution for an aeronautical system.
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FAINLEIB, A. M. "BIO-BASED CYANATE ESTER RESINS AND THERMOSTABLE POLYMER NETWORKS DERIVED THEREOF. MINI REVIEW". Polymer journal 44, n. 2 (20 giugno 2022): 93–100. http://dx.doi.org/10.15407/polymerj.44.02.093.
Testo completoAbstract (sommario):
This article is devoted to a review of the literature on a very promising direction in the chemistry of macromolecular compounds: the synthesis and study of polymers, more specifically, high performance polycyanurates based on bis(poly)phenols) of natural origin. Cyanate Ester Resins (CER) are characterized by a very regular structure of the polymer networks, namely polycyanurates (PCNs), obtained by their polycyclotrimerization. They have received much attention because of their unique combination of physical properties, including high thermal stability (> 400 °C), high glass transition temperature (> 270 °C), high fire-, radiation and chemical resistance, low water absorption and low outgassing, high adhesion to different substrates and excellent dielectric properties (ε=2,64−3,11). As a result, CER are currently used as structural or functional materials in aeronautics, space (composite strakes, fins, nose radomes, heat shields), printed circuit boards, adhesives etc. It has to be noted here that CER thermosetting resins, expanding the high-temperature operations regimes, are produced from synthetic petroleum-derived bisphenols, such as bisphenol A, which are toxic and dangerous for environment. In the past decade, naturally occurring phenolic derivatives have arisen as attractive precursors for developing new materials from renewable bio-sources for use in eco-friendly processes. Resins have been prepared utilizing either the whole liquid product or a phenolic-enriched fraction obtained after fractional condensation or further processing, such as solvent extraction or use of greener extraction methods. However, to date, none of the phenolic production and fractionation techniques has been utilized to allow for substitution of 100% of the phenol content of the resin without impacting its effectiveness compared to commercial formulations based on petroleum-derived phenol. The variable nature of the percentage of phenolic compounds in terms of purity from different batches of crops from one season to another and geographical influence does not allow from the reproducibility of phenolic compounds, and hence the resulting polymers. However, the direction that needs to be explored should be oriented towards complete replacement of petro-based phenolics with bio-based ones in the face of an urgent petroleum crisis. In addition, there is a necessity for materials showing enhanced applicability and improved performance. It is a beginning of the era of such a step, which requires further exploration of natural phenolic sources aimed at their enhanced utilization.
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Uzule, Kristine, e Irina Kuzmina-Merlino. "THE CONNECTION BETWEEN AN AIRPORT TYPE AND REVENUE STRUCTURE AT BALTIC STATES AIRPORTS". Aviation 26, n. 4 (28 novembre 2022): 183–94. http://dx.doi.org/10.3846/aviation.2022.17854.
Testo completoAbstract (sommario):
Airports are not only engines of transportation of passengers and cargo, but also commercial enterprises offering services far beyond transportation, which is why their revenues are formed by both aeronautical and non-aeronautical sales. Aeronautical revenues of some large European airports are higher than non-aeronautical revenues, whereas some regional and secondary European airports demonstrate the opposite trend. The aim of this research was to determine if there is a connection between an airport type and the ratio of aeronautical and non-aeronautical revenues at Baltic States airports in way that is consistent with the previous research. The aim was attained in three stages. The first, the definitions of the main and secondary airports were constructed via discourse analysis. The second, the structure of airport revenues of the selected Baltic States airports was analysed. The third, conclusions were made regarding a connection between an airport type and the revenue structure of these Baltic States airports. On the one hand, the research results suggested there might be a connection between an airport type and the revenue structure although this question requires further research, and on the other hand, the financial analysis showed that airports with a higher share of non-aeronautical revenues than aeronautical revenues were more resilient to crises.
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BARAN, Daniela, Romeo MARIN, Mihaela PETRE e Radu BOGATEANU. "A comparative study evaluating the hybrid composite-metal aviation structure". INCAS BULLETIN 13, n. 2 (4 giugno 2021): 3–9. http://dx.doi.org/10.13111/2066-8201.2021.13.2.1.
Testo completoAbstract (sommario):
The main purpose of this paper is to develop some numerical experiences based on mechanical tests performed on a hybrid composite metal aeronautical structure using finite element commercial codes (here NASTRAN). The results of the numerical simulations are consistent with the laboratory tests and encourage us to continue to improve the models using NASTRAN capabilities to obtain a realistic simulation of aeronautical structures made of such composites, taking into account their special properties.
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Zhang, Anming, e Yimin Zhang. "Airport capacity and congestion pricing with both aeronautical and commercial operations". Transportation Research Part B: Methodological 44, n. 3 (marzo 2010): 404–13. http://dx.doi.org/10.1016/j.trb.2009.09.001.
Testo completo
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del Prete, Antonio, Gabriele Papadia e Barbara Manisi. "Computer Aided Modelling of Rubber Pad Forming Process". Key Engineering Materials 473 (marzo 2011): 637–44. http://dx.doi.org/10.4028/www.scientific.net/kem.473.637.
Testo completoAbstract (sommario):
Rubber pad forming (RPF) is a novel method for sheet metal forming that has been increasingly used for: automotive, energy, electronic and aeronautic applications [1]. Compared with the conventional forming processes, this method only requires one rigid die, according to the shape of the part, and the other tool is replaced by a rubber pad [1]. This method can greatly improve the formability of the blank because the contact surface between the rigid die and the rubber pad is flexible. By this way the rubber pad forming enables the production of sheet metal parts with complex contours and bends. Furthermore, the rubber pad forming process is characterized by a low cost of the die because only one rigid die is required [2]. The conventional way to develop rubber pad forming processes of metallic components requires a burdensome trial-and-error process for setting-up the technology, whose success chiefly depends on operator’s skill and experience [4][5]. In the aeronautical field, where the parts are produced in small series, a too lengthy and costly development phase cannot be accepted. Moreover, the small number of components does not justify large investments in tooling. For these reasons, it is necessary that, during the conceptual design, possible technological troubles are preliminarily faced by means of numerical simulation [4],[6]. In this study, the rubber forming process of an aluminum alloy aeronautic component has been explored with numerical simulations and the significant parameters associated with this process have been investigated. Several effects, depending on: stamping strategy, component geometry and rubber pad characterization have been taken into account. The process analysis has been carried out thanks to an extensive use of a commercially finite element (FE) package useful for an appropriate set-up of the process model [7],[8]. These investigations have shown the effectiveness of simulations in process design and highlighted the critical parameters which require necessary adjustments before physical tests.
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Ramanatt, Peter Reji, K. Natarajan e K. R. Shobha. "Challenges in implementing a wireless avionics network". Aircraft Engineering and Aerospace Technology 92, n. 3 (7 febbraio 2020): 482–94. http://dx.doi.org/10.1108/aeat-07-2019-0144.
Testo completoAbstract (sommario):
Purpose Aircraft manufacturers for a long time have been looking to reduce the weight of on board equipment to enhance performance both from commercial aspect and from military aspect. The existing wired technology, using cables to connect different on board line replaceable unit apart from increasing the weight also increases the complexity related to electromagnetic interference, installation and maintenance. With continuous technology upgradation in the wireless domain, aviation industry is in the process of using wireless technology for intra-aircraft communication. Wireless technology can meet most of the challenges of modern avionics systems and significantly reduce the weight. This paper aims to look at various aspects of implementing a wireless network including issues related to wired network, aircraft channel, interference issues, suitable wireless protocols for aircraft applications and security aspects. Design/methodology/approach The paper has relied on literature study on wireless avionics intra-communications (WAIC) and the research work carried out in specific areas related to channel inside an aircraft, interference issues of wireless systems with onboard and external systems operating in the same band and security issues related to wireless network and security requirements of implementing an avionics wireless network (AWN). To identify suitable wireless protocol for AWN literature review and simulation to compare different protocols was carried out. Findings A single wireless protocol may not be suitable for all aircraft systems, and therefore, there may be a requirement to use multiple technologies. Mutual interference is not expected between WAIC systems with on board and external systems operating in the same band. The channel inside an aircraft is expected to be Rician (LOS) or Rayleigh (NLOS). However, additional measurements may have to be undertaken to have a generalized channel model. Security aspects in an AWN are critical and needs to be analyzed in detail prior to any wireless deployment. Practical implications Implementation of wireless technology can pave the way for usage of wireless technology for future generation avionics. With International Telecommunication Union allotting dedicated band for WAIC operations, considerable amount of research has been initiated in this field. It is believed that in the coming 2-3 years, the designers will be ready to replace the existing data wires with wireless transceivers. With radio technical commission for aeronautics and EURACAE involved in development of minimum operations performance standards for WAIC systems use of wireless for intra communication is bound to happen. Therefore, it is necessary to look at different issues for integrating wireless in the avionics domain. Originality/value The existing studies have been carried out in individual domains of using wireless in avionics. Separate studies and research work has been carried out for identifying wireless protocols, aircraft channel models, interference issues and security aspects. The paper has attempted to look at all these aspects together including certification.
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Pope, G. G. "Aeronautical technology — recent advances and future prospects". Aeronautical Journal 99, n. 983 (marzo 1995): 81–89. http://dx.doi.org/10.1017/s0001924000028244.
Testo completoAbstract (sommario):
SummaryRecent advances in aeronautical technology are reviewed, with particular reference to work in the United Kingdom, and the process is outlined whereby these have progressed from fundamental research through to exploitation in marketable products. Aerodynamic, materials, propulsion and avionic aspects are discussed and successful applications described in commercial and combat aircraft and helicopters. Current and anticipated advances in technology are considered in the context of possible future applications, including brief consideration of the possibility of a new generation of supersonic transport aircraft. Lessons are drawn from past experience on actions necessary now if these advances are to be exploited successfully in improving the performance, or reducing the acquisition or operating cost, of the next generation of aircraft, without introducing an unacceptable level of risk.