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Carthey, Jane. "Creating Safety II in the operating theatre: The Durable Dozen!" Journal of Perioperative Practice 29, n.º 7-8 (19 de dezembro de 2018): 210–15. http://dx.doi.org/10.1177/1750458918815558.
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The aviation industry calls the most frequently recurring factors that lead to incidents ‘the Dirty Dozen.’ The ‘Dirty Dozen’ includes, for example, stress, distractions and interruptions, team norms etc. The article adapts the concept of the Dirty Dozen from aviation to explore resilience in operating theatres. Taking a Safety II perspective, the article introduces the ‘Durable Dozen’: 12 regulatory, organisational, team and individual behaviours that enable theatre teams to resolve safety threats.
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Faury, Guillaume. "Prospective des marchés mondiaux de l’aéronautique, décarbonation et stratégie d’Airbus". Annales des Mines - Réalités industrielles Mai 2024, n.º 2 (14 de junho de 2024): 15–17. http://dx.doi.org/10.3917/rindu1.242.0015.
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La pandémie de Covid-19 a créé une crise sans précédent pour le transport aérien mondial, menant de nombreux observateurs à penser que l’aviation ne retrouverait jamais la croissance des années passées, et qu’elle pourrait même connaître un certain déclin. C’était oublier que le transport aérien est devenu un bien irremplaçable de nos sociétés modernes, transportant des biens et reliant les personnes, les cultures et les territoires, autant de facteurs de développement et de progrès. Ainsi, à la suite de mesures sanitaires strictes, le transport aérien a pu retrouver progressivement son niveau de 2019, avec une croissance qui semble désormais repartir à un rythme de l’ordre de 3,6 % par an. Cette forte demande met sous tension les chaînes de production d’Airbus et de ses sous-traitants, affaiblis par la crise. Mais le principal enjeu est d’assurer une croissance durable du transport aérien, compatible avec les objectifs de l’Accord de Paris sur le climat. C’est le défi que s’est donné Airbus avec l’ambition d’être le pionnier d’une aviation totalement décarbonée grâce à des avions de plus en plus performants en termes d’émissions, à des technologies de rupture, comme l’avion à hydrogène, et au recours massif aux carburants durables. Et ce, pour une aviation durable, mais aussi un monde plus sûr et plus uni.
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de Zotti, Alain, e André Bourdais. "Airbus pionnier d’une aviation durable, pour un monde ouvert et respectueux de l’environnement". Annales des Mines - Réalités industrielles Mai 2024, n.º 2 (14 de junho de 2024): 76–81. http://dx.doi.org/10.3917/rindu1.242.0076.
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Être une source d’inspiration est profondément ancré dans l’ADN d’Airbus, et aujourd’hui notre objectif est d’être le pionnier de l’aérospatiale durable, pour un monde sûr et solidaire. Depuis plus de cinquante ans, nous valorisons l’innovation pour réduire l’empreinte environnementale de nos produits et de nos activités. Un effort considérable a été fait pour promouvoir le renouvellement des flottes au sein des compagnies aériennes vers des avions de nouvelle génération plus performants, économes en carburant et respectueux de l’environnement. Nous nous attachons à développer et porter à maturité les technologies nécessaires à la décarbonation, notamment avec des évolutions en matière thermopropulsive des moteurs, ou plus révolutionnaire comme l’utilisation de l’hydrogène ; des essais en vol seront bientôt effectués sur l’un de nos avions d’essai. Un autre levier important est l’utilisation grandissante des carburants d’aviation durables pour atteindre les objectifs de réduction des émissions carbone du transport aérien d’ici à 2030. Un partenariat stratégique a d’ailleurs été récemment signé entre Airbus et TotalEnergies afin d’accélérer leur déploiement ; ce carburant fourni par TotalEnergies devrait permettre de réduire jusqu’à 90 % les émissions de CO 2 sur l’ensemble du cycle de vie, en comparaison de leur équivalent fossile. Enfin, « être pionnier dans l’aéronautique durable » signifie, pour nous, assumer notre responsabilité en tant que leader reconnu de notre industrie, pour créer une valeur à long terme pour nos parties prenantes et pour la société. Notre ambition comprend des engagements forts pour réduire nos impacts environnementaux et notre empreinte écologique, en adoptant une perspective de cycle de vie. Cette responsabilité environnementale commence dès la phase de conception, se poursuit durant le processus de fabrication et après la livraison, ainsi que dans le quotidien de chaque salarié, dans nos opérations industrielles et celle de notre chaîne d’approvisionnement. Toutes ces évolutions technologiques majeures et cette transformation de notre entreprise font d’Airbus un acteur majeur dans la société, avec des défis passionnants et stimulants à relever.
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Alomar, Iyad, e Irina Yatskiv (Jackiva). "DIGITALIZATION IN AIRCRAFT MAINTENANCE PROCESSES". Aviation 27, n.º 2 (5 de maio de 2023): 86–94. http://dx.doi.org/10.3846/aviation.2023.18923.
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Aircraft maintenance is considered as one of the major expenditures of aircraft operating costs. Notwithstanding that the new aircrafts, engines, and aircraft hard time parts became more durable and maintainable, the maintenance cost is still too high as against other costs like fuel and operational crews. Moreover, aircraft maintenance should be carried out with a high level of safety and security standards. All aircraft maintenance operations are subject to regulations by regulatory authorities. Such authorities can be attributed to European Union Aviation Safety Agency (EASA), Federal Aviation Administration (FAA) and National Civil Aviation Authorities (NAA). The last two decades have become a turning point in the transition from the paper form of the introduction of accounting for aircraft maintenance technical operations into electronic systems, despite all the difficulties associated with these procedures. Such difficulties are not limited to regulatory authorities, personnel training and investment which is case-sensitive for small companies. Similar to all other sectors of logistics and transportation, digitalization can be one of the key engines of change in aviation, especially in the aviation maintenance; thus, the study of digitalization effects on aircraft maintenance processes at present is an important factor for improving the maintenance processes and reducing the cost of aircraft maintenance. The objective of this research is to define the ability of aircraft maintenance and repair organizations to transform their processes. To that end, a data collection method in the form of a survey was implemented within Maintenance, Repair and Overhaul Organizations (MRO) and among aircraft maintenance engineers. The survey results demonstrate that the aircraft maintenance industry is not yet fully prepared for moving into digitalization in aircraft maintenance processes. However, at the same time, the study indicates the readiness of the personnel involved in the industry to improve themselves and their skills. The industry should invest in the improvement of safety and quality of tasks subject to digitalization by means of development of reliable software/hardware, and provide suitable training for safety and quality personnel.
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Safoklov, Boris, Oleg Dolgov, Andrey Rymarov e Irina Pocebneva. "Mobile technology platform - production of rapid deployment with small seriality". E3S Web of Conferences 458 (2023): 05032. http://dx.doi.org/10.1051/e3sconf/202345805032.
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In this paper, within the framework of the concept of “Industry 4.0”, the need to introduce the concept of “Mobile Technology Platform” for industries with small seriality and rapid deployment, the products of which are: special-purpose products (including aviation), spare parts for durable goods to ensure their prompt maintenance and repair as part of after-sales service.
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Serikbekuly, N., K. D. Ormanbekov, A. B. Shynarbek, A. Zh Zhassulan e B. A. Lobasenko. "PROSPECTS FOR THE USE OF MICROARC OXIDATION IN THE PRODUCTION OF AVIATION AND AUTOMOTIVE COMPONENTS". Bulletin of Shakarim University. Technical Sciences, n.º 3(15) (27 de setembro de 2024): 71–78. http://dx.doi.org/10.53360/2788-7995-2024-3(15)-11.
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This article discusses the prospects for the application of microarc oxidation (MAO) technology in the aviation and automotive industries. The MAO process allows the creation of durable, wear-resistant and corrosion-resistant coatings on the surface of metal parts, which significantly increases their durability and performance characteristics. Technological aspects of MAO are discussed, including surface preparation features, selection of electrolytes and control of process parameters. Examples of successful application of MAO in the production of aviation and automotive components are given. Also, directions for further research and development of the technology are explored, including the creation of new materials, combined coatings and the study of the durability of coatings under real operating conditions. The article emphasizes the importance of MAO as a promising technology for improving the reliability and efficiency of vehicles and equipment.
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Khammas, Ruqaya, e Heli Koivuluoto. "Durable Icephobic Slippery Liquid-Infused Porous Surfaces (SLIPS) Using Flame- and Cold-Spraying". Sustainability 14, n.º 14 (9 de julho de 2022): 8422. http://dx.doi.org/10.3390/su14148422.
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Icing and ice accretion cause severe problems in different industrial sectors, e.g., in aircrafts, aviation traffic, ships, solar panels, and wind turbines. This can lead to enormous economic losses and serious safety issues. Surface engineering can tackle these problems by designing surface structures to work as icephobic coatings and, this way, act as passive anti-icing solutions. In this research, slippery liquid-infused porous structures were fabricated using flame- and cold-spraying to produce polymer (LDPE and PEEK) coatings, and impregnated with a silicone lubricant. Microstructural details, surface properties, wetting behavior, and cyclic icing–deicing behavior were evaluated via ice adhesion measurements, which show the potential performance of SLIPS designs. All these SLIPS showed low or medium-low ice adhesion after the first icing-deicing cycle and the best candidate showed stable performance even after several icing-deicing cycles.
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Parisot, Frédéric. "La filière industrielle aéronautique et spatiale en route vers une aviation décarbonée". Annales des Mines - Réalités industrielles Mai 2024, n.º 2 (14 de junho de 2024): 66–68. http://dx.doi.org/10.3917/rindu1.242.0066.
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Si le transport aérien n’est responsable que d’environ 2,5 % des émissions de CO 2 d’origine humaine, le sujet doit néanmoins être traité pour que le transport aérien reste accessible au plus grand nombre, en toute sécurité. Les industriels de l’aéronautique, fédérés par le GIFAS, sont engagés dans la voie de la réduction de cet impact environnemental pour atteindre la neutralité carbone en 2050. Les acteurs du secteur, industriels, compagnies aériennes et aéroports, ont décidé de relever ensemble le défi de la décarbonation, en étant le premier secteur à avoir pris au niveau mondial des engagements précis et ambitieux en ce sens. La décarbonation constitue ainsi une nouvelle révolution dans l’histoire de l’aviation, et s’appuie sur différents leviers complémentaires dans le temps, détaillés ici. C’est la capacité d’innovation du secteur qui permettra à l’aviation de se décarboner et d’être un moyen de transport sûr, accessible à tous, et durable.
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Skorupka, Zbigniew. "Efficiency and Fatigue/Endurance Laboratory Tests of Aviation Friction Brakes". Fatigue of Aircraft Structures 2022, n.º 14 (1 de dezembro de 2022): 104–13. http://dx.doi.org/10.2478/fas-2022-0008.
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Abstract Brakes are one of the most important safety systems in moving vehicles and machines. In vehicles such as cars or motorcycles brakes are used for stopping, controlling speed, and sometimes changing direction of travel. In aircraft, the main function of brakes is to reduce landing speed. As landing is one of the most dangerous maneuvers in aircraft operation, brakes must be efficient and reliable in order to ensure safety of the crew, passengers, and cargo. The most efficient brakes nowadays are friction brakes where velocity is controlled by friction of a pair of specially designed materials, which ensure stable and high friction coefficient over the course of the required braking process. The process itself is the dissipation of energy during aircraft movement which generates very high temperatures in friction materials during the time of the braking process. The materials and the whole brakes have to be temperature resistant, and we must ensure braking parameters are stable during the whole process. The same principle relates to the endurance/fatigue of the brake assemblies which must be durable enough to survive as high number of braking cycles as possible without any failure, which can result in fatal consequences. Every friction pair and every newly designed brake assembly must be laboratory tested for efficiency and endurance/fatigue in order to be used in an aircraft or vehicle. In this paper, we present the basic set of laboratory tests in the scope of friction materials and brake assemblies. Results of the tests are used as confirmations/proofs of proper and safe operation of the brakes for use in vehicles, especially in aircraft but also in land-based vehicles.
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Prusak, Kamil, Janusz Zmywaczyk, Piotr Koniorczyk, Jan Godzimirski e Marcin Cegła. "Thermo-Mechanical Analysis of Chosen Epoxy Resins Used in Aviation Technology". Advanced Materials Research 1126 (outubro de 2015): 187–93. http://dx.doi.org/10.4028/www.scientific.net/amr.1126.187.
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In this paper the results of storage modulus (E’), loss modulus (E’’) and damping parameter tan (δ)=E''/E' of epoxy resins Epidian 57 and L285 with curing agents Z1 and LH285, respectively are presented. In addition to this the stress-strain and thermal expansion characteristics of Epidian 53, 57 and L285 were obtained experimentally in order to compare Dynamic Mechanical Analysis (DMA) results. Temperature range of DMA investigations using Netzsch (Germany) DMA 242C analyzer was from-120 °C to +110 °C at the heating rate of 1 K/min with frequency of {0.1, 1, 10} Hz, respectively. Netzsch DIL 402C dilatometer was used to study the thermal expansion of the tested samples within temperature range from 30 °C to 80 °C at 1 K/min of heating and cooling rates, respectively and Huang TA computer servo control material testing machine HT-2402 was applied to determine the stress-strain characteristics. Measurements of sample elongation ΔL and physical α* were performed twice in heating and cooling cycles. The glass transition temperature Tg determined from maximum of tan (δ) curve at f = 1Hz was equal to 76.7 °C for E57 and 87.2 °C for L285. It has been observed durable deformed shape of L285 sample with deflection in the middle about 5 mm just after finishing the DMA first run of heating which significantly affected DMA results during the second run of heating
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Dobryshkin, A. Yu, E. O. Sysoev e O. E. Sysoev. "Determination of the Influence of Reinforcement Direction of Open Thin-Walled Cylindrical Carbon Shells on Their Natural Vibrations". IOP Conference Series: Earth and Environmental Science 988, n.º 5 (1 de fevereiro de 2022): 052055. http://dx.doi.org/10.1088/1755-1315/988/5/052055.
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Abstract Nowadays, open cylindrical shells are widely used in structures in construction, aviation, energy, oil, and other industries. Shell structures are exposed to short-term cyclical influences in the course of operation; these influences cause forced vibrations of the structure which trigger the internal dynamic mechanisms, changing the natural vibrations of the structure, which has a significant impact on the strength characteristics of the shell. Carbon-fiber-reinforced plastics (CFRP) are used as an effective material for such structures. This is a durable and lightweight material. Due to its high cost, its application used to be efficient only in aircraft and in the space industry. Improvement of manufacturing techniques has made it possible to expand the range of CFRP applications. Due to their thinness, CFRP products are prone to vibrations. Vibrations can cause resonance condition, which can result in structural collapse.
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Mahalingam, Savisha, Salmi Mohd Yunus, Abreeza Manap, Nurfanizan Mohd Afandi, Rabiatul A. Zainuddin e Nurul F. Kadir. "Crack Propagation and Effect of Mixed Oxides on TGO Growth in Thick La–Gd–YSZ Thermal Barrier Coating". Coatings 9, n.º 11 (1 de novembro de 2019): 719. http://dx.doi.org/10.3390/coatings9110719.
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Thick thermal barrier coatings (TBCs) are the main choice in the aviation industry due to their ability to handle elevated temperature exposure in turbines. However, the efficacy of thick TBCs has not been adequate. This study presents a highly durable, thick top-coat (TC) of Lanthanum–gadolinium–yttria stabilized zirconia (La–Gd–YSZ) on high-velocity oxygen fuel (HVOF)-bond coat (HVOF-BC). Crack propagation was quantitatively assessed using a three-dimensional (3D) measuring laser microscope due to higher reliability in calculating the actual crack length of TBC. The findings revealed the HVOF-BC is highly durable with intact structural composition, while the conventional TBC of atmospheric plasma spraying (APS) bond coat (APS-BC) of the same composition and thickness with identical TC was detached at a crack-susceptible zone. The significant enhancement in HVOF-BC is due to the low mixed-oxides growth rate in thermally grown oxide (TGO) with a uniform and dense protective layer of stable Al2O3 which reduces crack propagation. Meanwhile, the failure in APS-BC can be attributed to the high TGO growth rate and thickness with segmented and unstable Al2O3. Furthermore, detrimental mixed oxides such as spinel Ni(Cr,Al)2O4 and NiO lead to disastrous horizontal and compressive cracks. To that end, we study the effect of TGO growth and crack propagation on HVOF-BC TBCs using APS-BC TBCs as a reference.
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Venkatesan, M., K. Palanikumar e S. Rajendra Boopathy. "Experimental investigation and analysis on the wear properties of glass fiber and CNT reinforced hybrid polymer composites". Science and Engineering of Composite Materials 25, n.º 5 (25 de setembro de 2018): 963–74. http://dx.doi.org/10.1515/secm-2017-0068.
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AbstractThe aviation, automobile, and consumer products industry requires long-life, durable, lightweight high-performance polymer matrix composites. Polymer fiber reinforced materials possess low weight and high specific quality along with high specific stiffness. The addition of carbon nanoparticles in the composites improves their mechanical properties, including wear enhancement, which leads to the utilization of these composites in different fields. The present work investigates the wear performance of glass fiber and carbon nanotube (CNT) reinforced hybrid polymer composites. Dry sliding tests for wear were conducted using a pin-on-disc wear tester by varying the load and speed. The worn surfaces were examined by utilizing scanning electron microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy, and atomic force microscopy. The result shows that the increase in volume percentage of CNTs in glass fiber reinforced polymer composites decreases the wear rate. The result also clearly states that the coefficient of friction increases with an increase in the CNT percentage.
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Su, Ru, Lei Huang, Changzhou Xu, Peng He, Xiaoliang Wang, Baolin Yang, Dayong Wu, Qian Wang, Huicong Dong e Haikun Ma. "Factors Influencing Residual Stresses in Cold Expansion and Their Effects on Fatigue Life—A Review". Coatings 13, n.º 12 (2 de dezembro de 2023): 2037. http://dx.doi.org/10.3390/coatings13122037.
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Cold expansion technology has been widely used in aviation industries as an effective method of improving the fatigue performance of fastener holes. It can improve the fatigue life several times over without adding weight, meeting the growing demand for lightweight and durable aircraft structures. In recent years, it has been extensively studied through extensive experiments and finite element simulations to analyze the residual stresses around the fastener hole. Appropriate process parameters lead to the generation of beneficial residual stresses that influence the material microstructure, thereby improving the fatigue life of the component. This paper summarized factors influencing residual stresses in cold expansion and their effects on fatigue life, and the strengthening mechanism, parameter optimization, and effect of anti-fatigue are discussed from the point of view of the residual stress and microstructure. The development of new cold expansion technologies and the research directions that can realize anti-fatigue technology efficiently are proposed.
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Tran, Anh Tien, e Nam Ngoc Linh Hoang. "Design and installation of vibration testing system for spring mounted model of wing". Science and Technology Development Journal 18, n.º 4 (30 de dezembro de 2015): 179–87. http://dx.doi.org/10.32508/stdj.v18i4.1004.
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This paper presents the design and installation of measuring vibration system in wind tunnel area 1m x 1m. The theoretical analysis of the spring structure in this model help we possible to design a system for wind tunnel by yourself with suitable area, wind speed as well as survey wing model to obtain results desire. This system helps us to observe the oscillation of wing survey by eyes, but to know exactly how wing fluctuates, also the pitching angle of wing, we use ultrasonic sensors to measure the distance variation, will be presented in more detail in the text. At the same time, the article also shows how to make a simple and durable wing model with NACA 0015 airfoil - wing model will be surveyed ranged in system above. The aerodynamic phenomena affect to the vibration of the wing are also mentioned and overcome in the design of the wing. Finally we process the data after measured to see the similarities between the experiment and the theoretical dynamics of aviation.
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Kosiek, Julia, Jan Nasur e Grzegorz Rutkowski. "Analysis of the Batychron Research Project". Scientific Journal of Gdynia Maritime University, n.º 121 (31 de março de 2022): 20–27. http://dx.doi.org/10.26408/121.02.
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The article presents the research project called ‘Batychron’. Batychron is a flexible underwater bell patented by the Gdynia Maritime University as a ‘device applicable in hydraulic engineering for underwater transport and diving with the safety of human life’ (patent number: PL192265 B1, Int. Cl B63C 7/12; B63C 11/44). Users of this device claim that the Batychron is the most revolutionary invention in the field of human activity underwater. Thanks to its advantages and low price, the Batychron may well become a device as common as the parachute in aviation in the future. The first prototype of the device was made in 2002. In 2021, after almost 20 years of using the Batychron in a marine environment, the Student Special Interest Group of Underwater Research “Sea Quest” operating at the Gdynia Maritime University decided to make a modified (improved) model of the device from modern materials (more durable) and prepare it for real sea trials. The main purpose of the article is to present the Batychron project construction and its application.
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Donadei, Valentina, Heli Koivuluoto, Essi Sarlin e Petri Vuoristo. "Icephobic Behaviour and Thermal Stability of Flame-Sprayed Polyethylene Coating: The Effect of Process Parameters". Journal of Thermal Spray Technology 29, n.º 1-2 (11 de novembro de 2019): 241–54. http://dx.doi.org/10.1007/s11666-019-00947-0.
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Abstract The present work investigates the effect of different process parameters on the production of low-density polyethylene (LDPE) coatings by flame spray technology. Previously, flame spraying of polymers has been successfully performed to obtain durable icephobic coatings, providing an interesting solution for applications facing icing problems, e.g. in marine, aviation, energy, and transportation industry. However, the fine tailoring of the process parameters represents a necessary strategy for optimising the coating production due to the unique thermal properties of each polymer. For this purpose, we vary the heat input of the process during flame spraying of the coating, by changing the transverse speed and the spraying distance. The results show that the variation in the process parameters strongly influenced the quality of the polymer coating, including its areal roughness, thickness, chemical composition, thermal stability, and degree of crystallinity. Furthermore, we demonstrate that these properties significantly affect the icephobic behaviour of the surface within the spray window of the chosen parameters. In conclusion, the relationship between the thermal degradation of the polymer and the icephobicity of the surface was defined. This highlights the importance of process parameter optimisation in order to achieve the desired icephobic performance of the LPDE coatings.
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Adamus, Janina, Katarzyna Dyja e Wojciech Więckowski. "Lubricants Based on Vegetable Oils as Effective Lubricating Agents in Sheet-Titanium Forming". Key Engineering Materials 687 (abril de 2016): 163–70. http://dx.doi.org/10.4028/www.scientific.net/kem.687.163.
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Sheet metal forming processes allow for production of lightweight and durable goods. For this reason, drawing operations have been widely used across the automotive, aviation and construction industries and for production of various components of machines. Despite the popularity of deep-drawing steel sheet metal, non-ferrous materials, such as aluminium, magnesium and titanium are also used for such purposes. Titanium materials seem to be particularly attractive due to a beneficial ratio of strength to density and excellent corrosion resistance in the most of technological environments. However, titanium and its alloys belong to a group of materials with low tribological properties and tendencies for galling and build-up of layers of the deformed material on the tool surface. Therefore, this study will discuss the results of the investigations concerning selection of technological lubricants based on vegetable oils used for the operation of forming of sheet metal made of commercially pure titanium (Grade 2). The focus of the experiment is on lubricants based on vegetable oils i.e. rapeseed oil, sunflower oil and olive oil. The main lubricating additive was boric acid and stearic acid. The study presents the results of the determination of friction coefficient during a strip drawing test.
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Alptekin, Artunç, e Hasan Çallioğlu. "Mechanical properties of starch bio-composite and molded pulp samples manufactured using pine and eucalyptus fibers". Polymers and Polymer Composites 31 (16 de março de 2023): 096739112311619. http://dx.doi.org/10.1177/09673911231161983.
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In recent years, one of the main challenges is to improve the mechanical performance of bio-composites to be used as structural parts for the construction, automotive, and aviation sector. This paper may contribute to developing durable structural bio-composite parts with starch addition. The mechanical properties of bio-composites reinforced by eucalyptus or pine fibers (48 wt %) compound with Cationic Starch (48 wt %) and Carboxymethyl cellulose (CMC) (4 wt %) were determined. The production method was a combination of molded pulp, extrusion, and compression molding production techniques. To see the effect of adding starch to bio-composites and different production methods, the mechanical performance of these natural fibers produced by the conventional molded pulp production method (without any additives) was also found and compared with the composite samples. Composite samples indicate significantly better tensile, flexural, and compressive values, at least four times, compared with the molded pulp samples. On the other hand, the molded pulp samples had more than 2 times better impact characteristics against composites. Using molded pulp technic in composite production (investigated in the study) is a new idea and may give some opportunities with its serial production compatibility and geometry freeness, to the industry.
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Ozdemir, Okan, Dilay Koksal e Ugur Kemiklioglu. "Load-carrying capacity of hot-pressed thermoplastic composite joints". Materials Testing 64, n.º 11 (1 de novembro de 2022): 1614–26. http://dx.doi.org/10.1515/mt-2022-0147.
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Abstract Composite joints have been commonly used in many industries such as aviation, aerospace, and automotive due to their advantages of being light and durable. Internal stresses may occur especially during the service life of these materials and decrease the load-carrying capacity of the joints. In this study, high density polyethylene (HDPE) and glass fiber reinforced polypropylene composite panels are used resorting to different combinations by using hot-pressing method as a single lap joint, and their mechanical properties are investigated under different temperatures, experimentally. Tensile tests were carried out at different temperatures in order to examine the temperature effect on load-carrying capacity of joints. Different bonding types of composites were compared to obtain the optimal joint configurations. The effect of low velocity impact on the failure response of the joints at impact energy levels of 5 and 10 J is also evaluated. From the tensile tests after impact treatment, it was concluded that transverse impact significantly decreased the load-carrying capacity of the single lap thermoplastic joints. Based upon the experimental results, it was concluded that HDPE–HDPE joints demonstrated higher tensile failure loads at 50 °C after transverse impact. Moreover, the tensile strength of all types of configurations decreased with increasing temperature.
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Elbakyan, Lusine, e Irina Zaporotskova. "Composite Nanomaterials Based on Polymethylmethacrylate Doped with Carbon Nanotubes and Nanoparticles: A Review". Polymers 16, n.º 9 (29 de abril de 2024): 1242. http://dx.doi.org/10.3390/polym16091242.
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Composite polymer materials have high strength and lightness, which makes them attractive for use in a variety of structures and products. The present article contains an overview of modern works devoted to the production of composite materials based on poly(methyl methacrylate) (PMMA) with improved characteristics. The possibility of obtaining such materials can be a key area for creating more efficient and durable products in various industries. Various methods were considered to improve the characteristics of PMMA by doping the polymer matrix with carbon nanotubes (CNTs), graphite, nanohydroxyapatite particles, micro-zirconia nanoparticles, titanium dioxide, etc. The possibilities of using the obtained composite materials in various industries such as aviation, automotive, construction, medical and others are discussed. This article also presents the results of our own research on the mechanisms of interaction of PMMA with single-layer CNTs, leading to the creation of a composite polymer system “PMMA+CNT”, achieved using the modern quantum chemical method DFT. This article presents a review of the recent research on the effect of CNTs on the mechanical and electrically conductive properties of nanocomposite materials. The outcomes of this study can be important for the development of science and technology in various fields, from fundamental chemistry to applied scientific research.
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Sukhanova, Olga, e Олексій Ларін. "Linear dynamic properties in curved laminated glasses". Bulletin of the National Technical University «KhPI» Series: Dynamics and Strength of Machines, n.º 1 (31 de dezembro de 2021): 44–47. http://dx.doi.org/10.20998/2078-9130.2021.1.230161.
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The study presents the results of linear dynamics of laminated glass panels with different curvatures. This is an actual task in the field of mechanical engineering, aviation, shipbuilding, energy, architecture, etc. Such composites are durable, easy to care for and have a wide range of design options. The aim of the work is to study the influence of the curvature parameter on the frequencies and modes of composites. The paper considers the linear characteristics for laminated glass with polyvinyl butyral interlayer. The article considers behavior of the triplex and the propagation of elastic waves in the linear state. The paper performs calculations using the finite element method in the framework of modal analysis in a three-dimensional formulation in the framework of a physical linear-elastic formulation. The study uses hexagonal finite element with 8 nodes with 3 degrees of freedom in each. This work model laminated glass with a curvature parameter ranging from 0 mm to 250 mm. The composite consisted of three layers: two glass layers thickness of each was 3 mm, and a polyvinyl butyral interlayer with 0.38 mm thickness. The size of the plates was 500×500 mm. As a boundary condition, the laminate was fixed on two opposite sides. The article performs mesh size convergence analysis. The results of natural frequencies in accordance with the curvature parameter are derived. The graphs of natural vibration modes are also shown, that give a clear view about the state of composites.
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Nickerson, William C., Nagaraja Iyyer, Keith Legg e Mehdi Amiri. "Modeling galvanic coupling and localized damage initiation in airframe structures". Corrosion Reviews 35, n.º 4-5 (26 de outubro de 2017): 205–23. http://dx.doi.org/10.1515/corrrev-2017-0025.
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AbstractTraditionally, airframe structures are designed for immediate mechanical performance and loads-only structural response; the lifetime of aircraft structures is predicted on these analyses and environmental degradation of properties over the life cycle and during operations is often an afterthought. Although the maintenance of aircraft structures is primarily determined by material degradation, galvanic management of airframe designs and corrosion-resistant material selection have never been done systematically. From end-of-life tear-down inspections, we know that, predominantly, structural failures are initiated from corrosion features, especially those accelerated by dissimilar material coupling. In its most simplistic form, this environmental exposure, “loading”, creates corrosion features, such as pitting, that produce crack initiation morphologies; cracks nucleate from these features and then grow under the combined influence of mechanical stress and corrosion, eventually leading to structural failure. There is clearly a strong correlation between corrosion and structural damage, which we think of as corrosion fatigue and stress corrosion cracking. Office of Naval Research’s Sea-Based Aviation program is developing computational approaches to corrosion activity prediction, crack initiation and crack growth, with the ultimate aim of predicting service life in terms of the combination of mechanical and chemical stress. This approach is intended to be the basis for design of durable aircraft structures, using design principles that will take into account both stress and corrosion in the design phase, rather than designing for stress and then maintaining for corrosion.
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Said, Izak M., e Imad L. Al-Qadi. "Iterative Framework for Performance and Environmental Impacts of Airfields". Transportation Research Record: Journal of the Transportation Research Board 2673, n.º 9 (5 de maio de 2019): 179–87. http://dx.doi.org/10.1177/0361198119844460.
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The main goal of a durable and sustainable airfield is to withstand repeated aircraft traffic loading while minimizing the environmental impact. The objective of this study is to develop a design-life cycle assessment (LCA) framework considering a balanced evaluation of structural adequacy, minimizing emission, and optimizing total energy demand. To achieve this objective, three steps are introduced: an evaluation of the structural adequacy of the design using the Federal Aviation Administration (FAA) pavement design software FAA rigid and flexible iterative elastic layered design; a preliminary performance check using field instrumentation responses; and a LCA of airfield sections using both deterministic and probabilistic approaches. In addition to presenting the design-LCA methodology, this paper offers a comparative evaluation that covers two perpetual designs (LFP1-N and LFP4-N) and one conventional section (LFC5-N). These pavement sections were built and tested at the National Airport Pavement Test Facility as part of construction cycle 7, funded by the FAA. Responses collected from instrumentation were used to compute field-based coverages to failure. Moreover, life cycle inventories from secondary sources were used to quantify the greenhouse gas emissions and energy demand associated with the construction of these sections. Results show inconsistencies between the field-predicted and theoretically predicted performance. This suggests the need for the additional calibration of the currently used performance models. Moreover, this study shows that under a specific asphalt concrete (AC) thickness limit, conventional AC may be more eco-friendly than a perpetual design.
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Azim, Mohd, Ammar Salman, Emad Ahmad, Md Kashif Alim, Mohd Ariz e Md Sufiyan. "Optimizing Tensile Strength in FRP Composites: Enhanced Fiber-Matrix Compositions". Journal of Advancements in Material Engineering 8, n.º 3 (2023): 36–45. http://dx.doi.org/10.46610/joame.2023.v08i03.004.
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In the world of construction materials Fiber Reinforced Polymers (FRPs) have emerged as a choice due to their impressive strength, lightweight nature and resistance to corrosion. This study focuses on enhancing the strength of FRP composites by exploring new combinations of reinforcing fibres and matrix materials. The historical challenges with corrosion in steel-reinforced structures led to the development of FRPs. Early innovators like Leo Baekeland and Norman de Bruyne played a role in laying the groundwork for composite materials, which found important applications in aviation, building panels and more. This study investigates how different percentages of glass fibers affect the properties of FRP composites. Glass fibers, thinner than hair but stronger than steel when compared by weight were combined with epoxy resin to create these composite materials. Through experimentation and analysis, we fabricated composites with varying volume fractions (0%, 1%, 2% and 3%) of glass fibres. These samples were then subjected to testing using a universal testing machine. The findings from this study provide contributions to the field of construction materials and engineering. The developed FRP composites do not address the long-standing corrosion issues associated with traditional steel-reinforced concrete but also offer a versatile and durable solution, for various applications. The effective incorporation of these cutting-edge materials into structures holds the potential for longer-lasting durability decreased expenses for upkeep and enhanced structural strength. Moreover, this study establishes the groundwork for progress in composite materials opening avenues for sustainable and resilient infrastructures, in the future.
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Smith, Adrian A. "Warfare and wind tunnel: engineers, physicists, and the evolution of combat aircraft 1914-1918". Journal of Physics: Conference Series 2877, n.º 1 (1 de outubro de 2024): 012027. http://dx.doi.org/10.1088/1742-6596/2877/1/012027.
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Abstract The British aircraft industry was transformed across the course of the First World War. Annual output grew exponentially, while by 1917-1918 the intensity of wartime research and development saw technologically advanced machines seeking air supremacy in all theatres of operation, most notably the Western Front. Capability had been inhibited by the absence of reliable, high performance power units, but ultimately production and procurement problems were resolved. This heroic narrative warrants qualification given the high ratio of poor to outstanding aircraft and the reality that in August 1914 Britain was by no means wholly unequipped to wage war in the air: the development programmes of the National Physical Laboratory and Royal Aircraft Factory, and the Royal Naval Air Service’s collaboration with science-based companies such as Short Brothers run counter to a popular belief that machines were still crudely built and militarily ineffective. There existed a working partnership between pioneer engineers and designers, schooled in applied science at metropolitan technical colleges, and graduate physicists and mathematicians encouraged by far-sighted dons to join a fledgling but fast-growing industry. That fusion of theory and practice, academic and industrial, was consolidated once British science’s human assets were mobilised to wage ‘industrial war’. Yes, aviation saw huge changes across the War, but the continuity is striking: before 1914 designers and air frame manufacturers were drawn from both the shop floor and the varsity, a wartime infusion of research scientists generated remarkable advances in aeronautics and in consequence a vital extension of Allied air power; and after 1918 companies survived retrenchment thanks to a durable combination of the entrepreneurial engineer and the experimental analyst.
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Mora, J., P. García, R. Muelas e A. Agüero. "Hard Quasicrystalline Coatings Deposited by HVOF Thermal Spray to Reduce Ice Accretion in Aero-Structures Components". Coatings 10, n.º 3 (20 de março de 2020): 290. http://dx.doi.org/10.3390/coatings10030290.
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Weather hazards, in particular icing conditions, are an important contributing factor in aviation accidents and incidents worldwide. Many different anti-icing strategies are currently being explored to find suitable long-lasting solutions, such as surface engineering, which can contribute to reduce ice accumulation. Quasicrystals (QCs) are metallic materials, but with similar properties to those of ceramic materials, such as low thermal and electrical conductivities, and high hardness. In particular, QCs that have low surface energy are commercially used as coatings to replace polytetrafluoroethylene (PTFE), also known as Teflon, on frying pans, as they do not scratch easily. PTFE exhibits excellent anti-wetting and anti-icing properties and therefore QCs appear as good candidates to be employed as ice-phobic coatings. Al-based QCs have been applied by High Velocity Oxyfuel (HVOF) thermal spray on typically used aeronautic materials, such as Ti and Al alloys, as well as steels. The coatings have been characterized and evaluated, including the measurement of hardness, roughness, wetting properties, ice accretion behavior in an icing wind tunnel (IWT), and ice adhesion by a double lap shear test. The coatings were studied, both as-deposited, as well as after grinding, in order to study the effect of the surface roughness and morphology on the ice accretion and adhesion properties. The QC coating was compared with PTFE and two polyurethane (PU)-based commercial paints, one of them known to have anti-icing properties, and the results indicate an ice accretion reduction relative to these two materials, and ice adhesion lower than bare AA6061-T6, or the PU paint in the ground version of one of the two QCs. Since the QC coatings are hard (GPa Vickers hardness > 5), a durable behavior is expected.
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Farahani, Emad, Andre C. Liberati, Christian Moreau, Ali Dolatabadi e Pantcho Stoyanov. "Comparative Evaluation of the Shear Adhesion Strength of Ice on PTFE Solid Lubricant". Lubricants 11, n.º 3 (27 de fevereiro de 2023): 105. http://dx.doi.org/10.3390/lubricants11030105.
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The development of a durable and green icephobic coating plays a vital role in the aviation industry due to the adverse impact of ice formation on aircraft performance. The lack of study into how temperature and surface roughness impact icephobicity is the main problem with present icephobic coatings. This study aims to qualitatively evaluate the icephobicity performance of a polytetrafluoroethylene (PTFE) solid lubricant film, as an environmentally friendly solution, with a custom-built push-off test device in different icing conditions utilizing a wind tunnel. The ice-adhesion reduction factor (ARF) of the film has been assessed in comparison to a bare aluminium substrate (Al 6061). The impact of surface energy was investigated by comparing the water contact angle (WCA), the contact angle hysteresis (CAH), and the pull-off force of the PTFE solid lubricant and Al with an atomic force microscope (AFM). The results of ice shear adhesion on the PTFE solid lubricant film showed a significant reduction in the ice adhesion force at various substrate temperatures and surface roughness compared to the bare aluminium substrate. The difference in the ice adhesion between the solid lubricant and aluminium alloy was attributed to the differences in the detachment mechanism. For the PTFE-based solid lubricant, the interfacial detachment mechanism was based on the formation of interfacial blisters towards the centre of the ice. Consequently, upon continued application of the shear force, most of the energy injected would be distributed throughout the blisters, ultimately causing detachment. In the comparison of ice adhesion on PTFE solid lubricant and bare aluminium, the film showed minimal ice adhesion at −6 °C with an adhesion force of 40 N (ARF 3.41). For temperature ranges between −2 °C and −10 °C, the ice adhesion for bare aluminium was measured at roughly 150 N.
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Stebeleva, Olesya P., Lyudmila V. Kashkina, Olga A. Vshivkova e Andrey V. Minakov. "Application of high-speed hydrodynamic technology for the production of graphene nanosuspensions from natural graphites". Siberian Aerospace Journal 25, n.º 4 (15 de dezembro de 2024): 521–30. https://doi.org/10.31772/2712-8970-2024-25-4-521-530.
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Carbon nanostructures have been in the focus of world science for more than 25 years, since the discovery of fullerenes in 1985, single-walled carbon nanotubes in 1993, graphene in 2004, graphene quantum dots in 2004. Graphene is a monocrystalline graphite films (2D material) with a thickness of several atoms that are stable under environmental conditions and they have excellent electronic, mechanical, chemical, thermal and optical properties. All over the world, research and development of new methods of using graphene in various fields such as energy, oil production, materials science, and electronics are actively carried out. Currently, the use of graphene-containing materials as modifiers for the creation of durable and effortless materials in aviation, automotive and other branches of engineering is an urgent problem. It is advisable to introduce graphene particles into the composition of composite materials using their stable dispersions in a liquid medium. The production of colloidal graphene suspensions is effective in many cases using the method of liquid phase exfoliation of graphite. The paper presents the results of studying the physico-chemical properties of aqueous graphene suspensions obtained by liquid-phase exfoliation of natural graphites using high-speed hydrodynamic technology. Graphite grades GK-1 and GAK-2 (Grafitservice, Chelyabinsk, Russia) are crystalline graphites obtained by enrichment of graphite ores and joint enrichment of natural graphite ores and graphite-containing waste from metallurgical industries, respectively. Graphite suspensions were prepared in distilled water with 1 wt.% graphite, surfactant was added to some samples, processing time (3–120 min), rotor rotation speed (4 000–11 000 rpm). The resulting graphene suspensions were investigated by XRD, by electron microscopy and sedimentation analysis methods. The particle size was determined using the DT-1202 electroacoustic spectrometer. The presence of multilayer graphene is confirmed by comparing the results of XRD with the literature data. Along with multilayer graphene, the presence of graphene dots was detected. Aqueous graphene suspensions for graphites with different sedimentation times have been obtained. For graphite GAK-2 – six days, for graphite GK-1 – 90 days, for graphite GK-1 + surfactant – 6 months.
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JENKINS, ANDREW R., JON J. SMALLIE e MEGAN DIAMOND. "Avian collisions with power lines: a global review of causes and mitigation with a South African perspective". Bird Conservation International 20, n.º 3 (19 de março de 2010): 263–78. http://dx.doi.org/10.1017/s0959270910000122.
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SummaryMany large terrestrial and wetland birds and some smaller, fast-flying species are prone to colliding with overhead wires associated with power infrastructure. A high proportion of these are threatened species and for some, collision with power lines and other man-made structures is a significant and damaging source of anthropogenic mortality. We review the existing literature on the nature, scale and impact of this problem worldwide, with particular emphasis on the South African situation, and focus on the evidence for and against various line configurations and devices proposed to mitigate the negative effects of overhead lines on bird populations. Cranes, bustards, flamingos, waterfowl, shorebirds, gamebirds and falcons are among the most frequently affected avian groups, and collision frequency is thought to be an influential factor in ongoing population declines in several species of cranes, bustards and diurnal raptors. The bulk of the research on this issue has been done in North America, Scandinavia, southern Europe and South Africa. Few comprehensive experimental studies on ways to reduce avian collisions with power lines have been carried out, although most of these have yielded quite clear results. Mitigation options considered include reviewing the placement of proposed new lines, removing the earth-wire which is usually the highest, thinnest and most problematic component in an overhead power line configuration, or else fitting this wire with markers – brightly coloured ‘aviation’ balls, thickened wire coils, luminescent, shiny or hinged flashing or flapping devices. All of these options reduce bird collision frequency overall by at least 50–60%, although the efficacy of line marking may be much lower for certain species (e.g. bustards). There remains considerable uncertainty about the best-performing marking device (perhaps because performance may vary with both local conditions and the species involved in each instance), and a durable, all-purpose device, that is effective both during the day and at night, has not yet been developed. We conclude by outlining a proposed experimental evaluation of the full array of collision mitigation options, to select the best approaches for use under South African conditions.
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МАШОВЕЦЬ, НАТАЛІЯ, АНТОН КОРІННИЙ e ТАРАС БАНАШКО. "INCREASE OF THE CORROSION-MECHANICAL WEAR RESISTANCE OF TITANIUM ALLOYS BY NITRIDATION IN THE GLOW DISCHARGE: A REVIEW OF MODERN RESEARCH". Herald of Khmelnytskyi National University. Technical sciences 331, n.º 1 (29 de fevereiro de 2024): 409–14. http://dx.doi.org/10.31891/2307-5732-2024-331-62.
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In this work, a review of modern research in the field of increasing the corrosion-mechanical wear resistance of titanium alloys using glow discharge nitriding is carried out. Titanium alloys, due to their unique properties, namely high strength, lightness, exceptional corrosion resistance and excellent biocompatibility, are widely used in aviation, medicine, engineering and many other industries. However, operational conditions in some applications require even greater improvement of the wear resistance and corrosion resistance of these alloys, which makes the search for effective methods of their improvement an urgent scientific and engineering task. Among the promising technologies that can be used to improve the corrosion-mechanical properties of titanium alloys, low-temperature anhydrous nitriding in a glow discharge should be considered. The use of low-temperature anhydrous nitriding in a glow discharge eliminates the growth of the base grain and hydrogen embrittlement of the surface. Also, low-temperature nitriding in a glow discharge makes it possible to increase the wear resistance of the surface of titanium alloys, while the saturation of the surface with nitrogen is controlled, which allows predicting the results of processing, does not lead to a change in the shape of parts. The analysis of scientific research shows that increasing the corrosion-mechanical wear resistance of titanium alloys by means of nitriding in a glow discharge is a promising direction that opens up new opportunities for industry and science. Progress in this field depends on further research, innovative development and the integration of the latest technologies, which together will contribute to the creation of more durable, efficient and environmentally friendly materials for a wide range of applications. In general, increasing the corrosion-mechanical resistance of titanium alloys by the method of nitriding in a glow discharge is a promising direction of research in Ukraine, which can lead to the improvement of the properties of titanium alloys and the expansion of their use in various industries.
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Aytan Movsumova, Aytan Movsumova. "STUDY OF TECHNOLOGY OF PRODUCTION OF SLAP PARTS FROM PLASTIC MATERIALS WORKING IN OIL-MINING EQUIPMENT". PAHTEI-Procedings of Azerbaijan High Technical Educational Institutions 12, n.º 01 (22 de janeiro de 2022): 29–33. http://dx.doi.org/10.36962/pahtei1201202229.
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This article is devoted to the study of the technology of preparation of smooth parts prepared of plastic materials working in oil-field equipment. The strengh of smooth part sin oil-field equipment,the collection of plastic parts, as well as complex properties are studied. Due to the fact that the components of plastic materials have high performance indicators,the usual processing methods are used by preparing them in various constructions. This shows that in the chemical environment,the items prepared of plastic materilas are electrically conductive,heat-resistant additives. This problem is especially important in the use of structures made of plastic materilas,which are widely used in oilfield equipment,and parts made of diferent types of heterogeneous materials.Their quality is formed in the process of design and construction. Ensuring the quality of components made of thermoplastic and thermosetting material sin the production process can be considered a topical issue.If we look at the pros and cons of the plastic materials quality management sector: It is possible to point out to the interested parties whether the existence of processing facilities has not been initiated for collection and segregation. On the downside, the existing standarts do not meet internaitonal standards and we can note that there are technological problems. Plastic materials are superior to metal sin many respects. Their quality indicators,the accuracy,strengh,level of cleanliness,ensure reliability and durability. The production and acquisition of new types of plastic mass is in the focus of attention of many research centers in the world’s leading countries. Soviet scientists were the first to invert endless screwredcers made of plastic. These examples are 10 times cheaper than in previous years, and 5-6 times light. For example, in Russia Karajoyev plastic plant, Lyubucevsk plastic plant, etc. such as large plastic plants are currently operating. Currently, the industry cannot be imagined without plastic mass. We can call the twentieth century the polymer century. The appliciation of plastic materials of plastic materials has many advantages in industry. For example,duet o its low weight and thermal and electrical conductivity,it is used in industries in developed countires. They also have high static and dynamic properties. The advantage of the dynamic feature is the application of plastic material sin areas such as radio engineering and electrical engineering. Examples of areas where smooth parts made of plastics are applied include machine building, aviation, petrochemistry, missile technology and instrument making. Smooth parts made of plastic materials have high reliability, durability and longevity.İn developed countiries, 40-50 percent of the materials used in mechanical engineering,instrument making and other industries are plastics of various brands,Plastics are easy to-process,low-cost and durable parts. Smooth parts made of plastics have high reliability, durability and longevity. The article analyzes the operation of plastic mass components,the analysis of the technology of production of smooth parts made of plastic materials used in oilfield equipment,as well as their strengh and reliability. Keywords: Plastic material, quality indicators, thermoset materials, performance indicators.
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Hauch, Anne, Peter Gustav Blennow, Kim N. Dalby, Daniel Bovin Drasbæk, Thomas Heiredal-Clausen, Aiswarya Krishnakumar Padinjarethil, Giovanni Perin, Jeppe Rass-Hansen, Elena Marzia Sala e Ramchandra Tiruvalam. "The Topsoe Perspective: From Electrode Nanostructures to MW Scaled SOEC Systems". ECS Meeting Abstracts MA2023-01, n.º 54 (28 de agosto de 2023): 171. http://dx.doi.org/10.1149/ma2023-0154171mtgabs.
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Topsoe has the strategic vision of becoming global leader in carbon emission reduction technologies by 2024. This will be reached via Topsoe’s range of energy-efficient technologies to produce clean transportation fuels as well as ammonia, methanol and hydrogen, which are universally seen as the most important fuels and chemicals of the future. Topsoe develops solutions for decarbonizing hard-to-abate sectors such as steel, cement, chemicals, shipping, and aviation. For example, in 2022 Topsoe helped reduce their customers CO2 emissions by more than 16 million tons, corresponding to 21% of the annual Danish CO2e emission. For decades, Topsoe has provided energy efficient solutions in the chemical industry employing heterogenous catalysis, but now Topsoe will supplement these products with Power-to-X solutions. A key technology in these Power-to-X plants will be the electrolysis system. Topsoe offers the most energy efficient electrolysis solution, namely the solid oxide electrolysis cell (SOEC) technology for its Power-to-X solutions. Topsoe’s expertise in heterogenous catalysis contributes to seamless downstream processing of products (H2, CO or CO+H2) from the electrolysis system and ensures efficient conversion from renewable energy to valuable e-fuels. To reach the ambitious carbon emission reduction targets, an increase in electrolysis capacity is required. To enable this, Topsoe has announced the building of an SOEC manufacturing facility in Denmark. When operational in 2025, the facility will produce electrolysis stacks and modules with a capacity of 500 MW*) per year with the first agreement (a reservation of 500 MW capacity) already announced 1. In this presentation we will provide an overview of Topsoe’s expertise, results, and initiatives in the field of SOEC. This will span from studies of materials properties, electrode nanostructures, electrochemical performance of cells and stacks, to the design of MW-sized systems, and towards commercialization of our TOPSOE SOEC electrolyzer plants as illustrated in Figure 1. The TOPSOE™ SOEC technology is applies fuel electrode supported Ni/YSZ based cells. In line with reports in literature 2–6, we acknowledge that he SOEC technology is still not as mature as is low temperature equivalents, and as such significant R&D work is ongoing on increasing the lifetime of the cells. Recognizing the importance of high performing and durable electrodes; we will in this presentation give examples on studies of electrode nano- and microstructures applying advanced characterization techniques and illustrate the use of impedance spectroscopy for electrochemical characterization of SoA SOEC cell performance. Furthermore, stack test results applying Topsoe’s stack technology for H2O electrolysis will be presented. Finally, the presentation will provide a status of and outlook for Topsoe’s upscaling of SOEC production capacity. As a concluding remark, Topsoe’s TSP-2 SOEC stack technology platform for production of H2 is being up-scaled now and ready for commercialization. Optimizing the TSP-2 platform will continue at Topsoe, by extensive R&D efforts in SOEC for the development of future even higher performing and more durable cells, stacks and modules. This is done while up-scaling and commercialization the present TSP-2 SOEC technology to provide inexpensive green H2 to fuel the green transition already now. Figure 1 : Illustration of Topsoe’s activities in SOEC spanning from fundamental studies of electrodes; exemplified by the TEM image of fuel electrode/electrolyte interface (top); to performance measurements scaling from cells, to stacks and systems; illustrated by key numbers from the Topsoe TSP2-stack platform (bottom) References P. Blennow, T. Heiredal-Clausen, J. Rass-Hansen, J. B. Hansen; M. Hultqvist, and P.-G. Moses, in Proceedings - 14th Europrean Solid Oxide Fuel and SOE Cell Forum, p. A0304 (2022). M. B. Mogensen, M. Chen, H. L. Frandsen, C. Graves, J. B. Hansen, K. V. Hansen, A. Hauch, T. Jacobsen, S. H. Jensen, T. L. Skafte and X. Sun., Clean Energy, 3, 175–201 (2019). M. Riedel, M. P. Heddrich, and K. A. Friedrich, Fuel Cells, 20, 592–607 (2020). M. Trini, A. Hauch, S. De Angelis, X. Tong, P. V. Hendriksen and M. Chen, J. Power Sources, 450, 227599-227609 (2020). Y. Shang, A. L. Smitshuysen, M. Yu, Y. Liu, X. Tong, P. S. Jørgensen, L. Rorato, J. Laurencin, and M. Chen, J. Electrochem. Soc., submitted (2022). M. B. Mogensen, A. Hauch, X. Sun, M. Chen, Y. Tao, S. D. Ebbesen, K. V. Hansen, and P. V. Hendriksen, Fuel Cells, 17 (2017). *) Agreement between First Ammonia and Topsoe A/S announced Sept. 14th 2022; see https://blog.topsoe.com/topsoe-and-first-ammonia Figure 1
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Normand, Thibaud. "La décarbonation du secteur aérien au défi de l’accès à l’énergie décarbonée". Annales des Mines - Responsabilité et environnement N° 113, n.º 1 (23 de janeiro de 2024): 15–19. http://dx.doi.org/10.3917/re1.113.0015.
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Le secteur aérien a adopté en 2021 l’objectif de la neutralité carbone d’ici 2050 et convergé rapidement sur les leviers de décarbonation requis pour atteindre cet objectif. Cette décarbonation nécessite toutefois le développement massif et rapide d’une filière de carburants aériens durables. Aux côtés de la biomasse, dont les ressources sont empreintes d’incertitude, l’électricité décarbonée apparaît clé pour la production de carburants de synthèse. Le secteur aérien français pourrait ainsi représenter une consommation électrique indirecte de l’ordre de 150 TWh en 2050. Le développement d’une nouvelle filière industrielle de production de carburants de synthèse, fortement électro-intensive, représente une opportunité de nouvel usage pour l’électricité nucléaire. Le nouveau nucléaire devra toutefois se montrer compétitif face aux sources d’électricité renouvelables centralisées, sur un marché des carburants aériens durables ou Sustainable Aviation Fuels (SAF) qui sera mondial.
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Fernández Suarez, Daniela. "Diseño de un Banco de Pruebas Experimental para Simulación del Comportamiento de la Estructura Alar de un MUAV." Journal Boliviano de Ciencias 15, n.º 47 (31 de dezembro de 2019): 33–44. http://dx.doi.org/10.52428/20758944.v15i47.305.
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Los vehículos aéreos no tripulados conocidos como UAVs fueron creados con propósito militar en el campo aeronáutico, surgiendo grandes avances en el área de diseño de UAVs en los últimos años. Este documento presenta los diferentes parámetros que debe ser considerado en el diseño alar de un Mini vehículo aéreo no tripulado bajo la normativa de FAA (Federal Aviation Administration) y EASA (European Union Aviation Safety Agency).El objetivo del presente estudio fue proponer el diseño conceptual de un banco de pruebas experimental para la simulación del comportamiento de la estructura alar de un MUAV (Miniature Unmanned Aerial Vehicle – Vehículo Aéreo No Tripulado en Miniatura). El diseño fue realizado utilizando diferentes softwares: tales como SolidWorks, en la parte de diseño del ala; XFLR5, para simulaciones aerodinámicas, y ANSYS-Workbench para el análisis estructural del ala. Todo esto se elaboró para obtener las cargas aerodinámicas (sustentación) más críticas distribuidas en superficie alar durante vuelo.
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Tytgat, Luc. "La réglementation, la certification et leurs effets". Annales des Mines - Réalités industrielles Mai 2024, n.º 2 (14 de junho de 2024): 18–21. http://dx.doi.org/10.3917/rindu1.242.0018.
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L’article traite des défis et des efforts de transformation nécessaires dans l’industrie aéronautique pour faire face à la concurrence et au changement climatique. Il souligne la nécessité pour l’industrie d’adopter des carburants d’aviation durables (SAF) et d’explorer les technologies d’avions électriques, hybrides et à hydrogène pour réduire les émissions de carbone. Le "Green Deal" de l’Union européenne et des initiatives comme "ReFuelEU Aviation" sont mentionnés comme stratégies clés pour décarboner l’aviation en encourageant l’intégration des SAF. L’Agence européenne de la sécurité aérienne (EASA) joue un rôle crucial dans la supervision de cette transition, assurant la sécurité et adaptant les cadres réglementaires pour soutenir l’innovation et la durabilité environnementale. La collaboration entre les parties prenantes de l’industrie, les institutions de recherche et les organismes réglementaires est soulignée comme essentielle pour atteindre un avenir neutre en carbone dans l’aviation.
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Ramón-Bonilla, Germán Darío. "Riesgos cibernéticos para la aviación regular “el 11 de septiembre cibernético”". Revista Ciberespacio, Tecnología e Innovación 1, n.º 1 (30 de junho de 2022): 93–98. http://dx.doi.org/10.25062/2955-0270.4775.
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Durante los últimos años, en particular a partir de año 2020, se ha evidenciado un incremento considerable de ataques cibernéticos a la aviación, en particular a las aerolíneas, y en menor proporción a las entidades encargadas de liderar y controlar los servicios de tránsito aéreo o Civil Aviation Authorities (CAA). Tal como le sucedió a la Administración Federal de Aviación (FAA) que en un lapso menor a tres meses fue víctima de dos ataques a la disponibilidad de sus sistemas de información, afectaciones que colocan en evidencia que Estados Unidos a pesar de ser uno de los países con mayor madurez cibernética, aún presenta vulnerabilidades que se deben contrarrestar. Por tal motivo, este articulo explora los riesgos cibernéticos para la aviación regular.
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León Vargas, Karim. "La Compañía Colombiana de Navegación Aérea, 1919-1921. Una aventura empresarial pionera en Suramérica". Lecturas de Economía, n.º 68 (11 de novembro de 2008): 195–215. http://dx.doi.org/10.17533/udea.le.n68a270.
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La temprana participación de empresarios colombianos en el establecimiento de compañías de aviación en Colombia durante la primera década del siglo XX, estuvo marcada por el riesgo ante una industria aeronáutica apenas explorada a nivel mundial. El artículo describe la creación y el funcionamiento en 1919, de la primera compañía de aviación en Colombia: Compañía Colombiana de Navegación Aérea, CCNA. La documentación proveniente de archivos personales, diarios y prensa de la época, permitió explorar la corta vida de esta compañía. Este primer intento empresarial abrió el camino de lo que se convertiría años más tarde en una lucrativa industria que revolucionó la forma de trasladarse de un lugar a otro y fortaleció los vínculos económicos y políticos entre zonas aisladas geográficamente. Palabras clave: historia de la aviación, transporte, modernización, historia empresarial, accidentes de aviación. Classification JEL: N46, N76, N86. Abstract: The early participation of Colombian entrepreneurs in the establishment of airlines in Colombia during the first decade of the twentieth century was marked by risk, faced with an aviation industry that recently began worldwide. This article describes the creation and operation in 1919 of the first airline in Colombia: Compañía Colombiana de Navegación Aérea, CCNA. The documentation from personal files, newspapers and press at the time, allowed to explore the short life of this company. This first attempt paved the way for what would become years later in a lucrative industry that has revolutionized the way of moving from one place to another and strengthened economic and political ties between geographically isolated areas. Keywords: history of aviation, transport, modernization, business history, aviation accidents. Classification JEL: N46, N76, N86. Résumé: Le risque d'investissement dans une industrie aéronautique à peines explorée au niveau mondial, caractérise la précoce participation des chefs d'entreprise dans l'établissement des compagnies d'aviation en Colombie pendant la première décennie du XXème siècle. Cet article décrit la création et le fonctionnement, en 1919, de la première compagnie d'aviation en Colombie, appelée Compagnie Colombienne de Navigation Aérienne, CCNA. L'étude de la courte vie de cette compagnie a été possible grâce aux archives personnelles, aux articles des journaux et à la presse de l'époque. Cette première tentative entrepreneuriale a ouvert la porte à la transformation, des années plus tard, d'une industrie très lucrative qui révolutionnerait définitivement la façon de se mobiliser en Colombie, en renforçant les liens économiques et politiques entre les zones isolées du pays. Mots clef: histoire l'aviation, transport, modernisation, histoire entrepreneuriale, accidents d'aviation. Classification JEL: N46, N76, N86.
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Lacki, P., e A. Derlatka. "The Plastic Deformation of RFSSW Joints During Tensile Tests / Deformacja Plastyczna Wybranych Połączeń RFSSW Podczas Rozciągania". Archives of Metallurgy and Materials 60, n.º 4 (1 de dezembro de 2015): 2585–92. http://dx.doi.org/10.1515/amm-2015-0418.
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The dynamic development of the friction stir welding (FSW) technology is the basis for the design of durabe joints inter alia in the aviation industry. This technology has a prospective application, especially for the aluminum alloys. It is suitable for a broad spectrum of permanent joints. The joints obtained by FSW technology are characterized by good mechanical properties. In this paper, the friction stir spot welding joints were analysed. The example of a structure made using this technology were presented. The lap joints made of 2mm Al 6061-T6 sheets were the investigation subject. The different spot welds arrangements were analysed. The tensile test were performed with optical deformation measurement system, which allow to obtain the plastic deformation field on the sample surface. The plastic strain graphs for the characteristic line passing through the maximum deformation were registered and presented. The experimental results were compared to the FEM numerical analysis. The numerical models were built with 3D-solid elements. The boundary conditions, material properties and geometry of the joints were identical as during experimental investigation. The mechanism of deformation of welded joints during tensile test was described and explained. It has been found that the arrangement of the spot welds with respect to the tensile direction has an important influence on the behaviour and deformation of lap joint.
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Das, Kishore Kumar, e Rupsa Mahapatra. "Impact of COVID-19 on the perception of Indian investors towards investment in equity fund". International Journal of Financial Engineering 07, n.º 03 (setembro de 2020): 2050040. http://dx.doi.org/10.1142/s2424786320500401.
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During the post demonetization and GST, Indian economy was struggling continuously to recover from the economic crisis. In the financial year 2019–2020, GDP rate fell from 7% to 5.4% which is about 18.20%. BSE Sensex index was 42273 as on January 20th of 2020 but on April 8, 2020, it was 29894. During the Financial year 2019–2020, a reduction of 26% in mid cap index was observed, but at the same time, sensitive index reduced by 22%. These things affect the share market and financial stability of people. The stock market over the last one-year became volatile and crashed. To handle the downwards economy, Government took the initiative and announced deep tax cuts for businesses in the month of August 2019. But in the beginning of the year 2020, there was another sluggish phase which stubborn the economy. This time, it was a virus, named as COVID-19(coronavirus), which created a pandemic situation and spread all over the world. Nation-wide lock down was announced to fight with COVID-19 as there was no vaccine introduced. Starting from agriculture to textile, apparel, automotive, aviation, hotels and restaurants, poultry, chemicals, consumer durables, entertainment, sports, FMCG (fast moving consumer goods), pharmaceutical, ecommerce, IT and moreover corporate sectors were adversely affected due to this pandemic and lock down rules. Therefore, this paper focuses on the impact of corona on the perception of Indian investors towards investment in equity fund.
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Junior, Carlos André Vaz. "Tomada de decisão em condição de informação parcial: estudo de caso em acidente aéreo / Decision making under partial information: case study in aviation accident". Brazilian Journal of Development 8, n.º 4 (12 de abril de 2022): 25769–94. http://dx.doi.org/10.34117/bjdv8n4-206.
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Em pouco mais de cem anos as aeronaves passaram de sonhos para máquinas modernas que cruzam oceanos e transportam milhares de pessoas todos os dias. A difusão do transporte aéreo somente foi possível graças ao desempenho crescente em termos de segurança, levando o risco de acidentes aéreos para valores realmente baixos. Redundâncias e equipamentos de segurança foram incorporados aos projetos, funcionando como camadas preventivas e mitigadoras na busca pela redução máxima do risco. Embora tecnologicamente sofisticados, anomalias em equipamentos, seja por erro de projeto, falhas de manutenção ou eventos aleatórios podem sempre ocorrer. E quando uma falha acontece a última camada de proteção é a tripulação. Piloto e copiloto se tornam responsáveis por reestabelecer a ordem e conduzir aeronave e passageiros de volta ao solo em segurança. Porém, nessas situações normalmente os tripulantes não dispõem de todas as informações necessárias para entender o que está ocorrendo e assim tomar decisões. A decisão precisa ser realizada em um contexto de informação parcial e com enorme pressão temporal, condições típicas para a ocorrência dos chamados “erros humanos”. Neste artigo analisou-se acidente ocorrido em setembro de 2008 envolvendo aeronave executiva Learjet 60. Durante tentativa de decolagem no aeroporto da cidade de Columbia, na Carolina do Sul, nos Estados Unidos, um dos pneus do trem de pouso principal colapsou, gerando enorme trepidação e desviando a aeronave de seu rumo. Surpreendidos pela falha já em alta velocidade, a tripulação inicialmente diverge sobre a melhor ação a ser adotada, mas rapidamente opta por interromper a corrida de decolagem. Todavia na sequência os demais pneus também colapsam, projetando detritos contra o dorso do Learjet e danificando equipamentos críticos – inclusive um sensor fundamental para o acionamento dos reversos. A falha nos reversos surpreende pela segunda vez a tripulação, que se vê sem opções para conter a aeronave ainda no interior da pista. O Learjet cruza a cabeceira oposta e colide com inúmeros obstáculos, matando quatro dos seis ocupantes. Falhas de manutenção e de projeto prepararam terreno para que este acidente viesse a ocorrer, porém foram as decisões da tripulação, tomadas a partir de informações parciais e enorme pressão temporal, que completaram a cadeia de eventos.
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Mantilla Pérez, Liliana Yaneth, e José Isaac Ordóñez Castellón. "Transición de la autoridad aeronáutica de Dirección General a Agencia Hondureña de Aeronáutica Civil". Ciencias Espaciales 9, n.º 1 (4 de fevereiro de 2017): 316–31. http://dx.doi.org/10.5377/ce.v9i1.3139.
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La Dirección General de Aeronáutica Civil (DGAC) estuvo adscrita a la Secretaría de Infraestructura y Servicios Públicos (INSEP) durante 63 años, presentando problemas por la dilación de los procesos y procedimientos para ejercer una estricta vigilancia a la seguridad operacional en los aeropuertos internacionales y aeródromos del país, lo cual está evidenciado en el Reporte de “International Aviation Safety Assessment (IASA) de la Federal Aviation Administration (FAA - Results); debido principalmente a la: falta de personal especializado y certificado y a las carencias presupuestarias; esta situación tuvo como resultando la no observancia a las normativas internacionales por parte del Estado de Honduras. Mediante decretos ejecutivos (PCM-001-2014 del 22 de febrero de 2014,PCM-047- 2014 del 10 de octubre de 2014 y PCM-022-2015 del 18 de mayo de 2015) la DGAC pasó a formar parte del Gabinete Sectorial de Seguridad y Defensa, y se dispuso la creación de la Agencia Hondureña de Aeronáutica Civil (AHAC), como un ente desconcentrado de la Secretaría de Defensa Nacional (SEDENA); se supone que, la transición de la DGAC a AHAC permitirá a la entidad tener autonomía técnica, administrativa y financiera, favorecer la formulación planes, programas, proyectos de fortalecimiento institucional para garantizar el cumplimiento de los estándares y potenciar el capital humano con competencias aeronáuticas, para lograr la certificación de los aeropuertos hondureños. Esta investigación es de tipo cualitativa, ya que el proceso de transición corresponde a una separación de la Secretaría de Infraestructura y Servicios Públicos (INSEP) a la Secretaría de Defensa Nacional (SEDENA), a fin de operar como una institución desconcentrada. Siendo que el proceso de transición es el camino indicado para que la AHAC genere la independencia técnica, administrativa y financiera necesaria para cumplir con los estándares en materia de aviación civil internacional.Los principales resultados de la investigación destacan: 1) Una marcada resistencia al cambio, producto de los procedimientos agresivos utilizados en la transición; derivado de un cambio abrupto, se observó un claro desacuerdo por parte de algunos colaboradores con los temas relacionados a la transición (50% de la institución). 2) Desinformación en relación al nuevo sistema administrativo, por el cual, se rige la Agencia Hondureña de Aeronáutica Civil, lo cual se respalda, por la falta de comunicación formal escrita. 3) Los colaboradores de la Agencia ven el proceso de transición como algo negativo para la aviación civil de Honduras y a la vez, no sienten que la nueva institución les pueda brindar estabilidad laboral y se ha generado mucha incertidumbre en el personal. 4) El personal no siente que el proceso de transición haya sido necesario. Y una gran parte del personal no tiene ninguna expectativa con el proceso de transición, mostrando un alto nivel de desánimo. 5) Una minoría considera que el proceso de transición traerá oportunidades para adquirir nueva tecnología, capacitaciones, personal calificado y mejoras para la institución.
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Diaz Olariaga, Oscar. "Airport competition, general framework of analysis". Dimensión Empresarial 17, n.º 1 (9 de dezembro de 2018): 77–89. http://dx.doi.org/10.15665/dem.v17i1.1611.
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Research article. Over the past 25 years the aviation market liberalization has been one of the factors driving the changing business environment in which airports operate today. These are beginning to stop being natural monopolies and are already competing with their market power being threatened. The factors driving airport competition are: greater freedom and flexibility of airlines to decide where their fleet operates, and their ability to change base of operations; more and better options for passengers to plan and decide where to start and finish their trips / tours; privatization of airports; and the entry into the market of new airports. This review article analyzes, through these factors, and from a general framework, the characteristics of airport competition today.ResumenArtículo de investigación. Durante los últimos 25 años la liberalización del mercado de la aviación ha sido uno de los factores que impulsó el cambiante entorno comercial en el que operan los aeropuertos hoya. Estos están empezando a dejar de ser monopolios naturales y ya compiten entre sí, con lo que su poder de mercado se ve amenazado. Los factores que impulsan la competencia aeroportuaria son: una mayor libertad y flexibilidad de las líneas aéreas para decidir desde donde operan su flota, y su capacidad de cambio de base de operaciones; más y mejores opciones de los pasajeros para planificar y decidir desde donde iniciar y terminar sus viajes/tours; la privatización de los aeropuertos; y la entrada al mercado de nuevos aeropuertos. Este artículo de revisión analiza, a través de dichos factores, y desde un marco general, las características de la competencia aeroportuaria hoy en día.ResumoArtigo de pesquisa. Nos últimos 25 anos, a liberalização do mercado de aviação tem sido um dos fatores que impulsionam o ambiente de negócios em mudança em que os aeroportos operam hoje. Estes estão começando a deixar de ser monopólios naturais e já estão competindo uns com os outros, com seu poder de mercado sendo ameaçado. Os fatores que impulsionam a concorrência nos aeroportos são: maior liberdade e flexibilidade das companhias aéreas para decidir onde sua frota opera e sua capacidade de mudar a base de operações; mais e melhores opções para os passageiros planejarem e decidirem por onde começar e terminar suas viagens / passeios; privatização de aeroportos; e a entrada no mercado de novos aeroportos. Este artigo de revisão analisa, através destes fatores, e de um quadro geral, as características da competição aeroportuária hoje.
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Souza, Ingrid Monteiro Peixoto de, Thiago Melo Souza, José Danilo Costa Souza Filho, Maria do Carmo Felipe de Oliveira e Dimitrie Nechet. "Estudo de Frequência da Ocorrência de Rajada de Vento e seu Papel na Segurança das Operações Aéreas no Aeródromo Internacional de Belém-PA (Wind Occurrence Frequency Study and Its Importance in Air Operations Security on Belém's International Aerodrome)". Revista Brasileira de Geografia Física 7, n.º 6 (25 de fevereiro de 2015): 1110. http://dx.doi.org/10.26848/rbgf.v7.6.p1110-1118.
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Este trabalho teve como objetivo estudar a freqüência de ocorrência de rajada de vento e sua importância na segurança das operações aéreas, uma vez que estas apresentam significativas variações de intensidade do vento, podendo ocasionar, inúmeros riscos para a aviação, desde desconforto durante o voo, até perdas de vidas humanas. Os dados foram obtidos no Aeródromo Internacional de Belém do Pará, no período de 2009 a 2012, onde foram realizadas análises estatísticas, bem como, estudos das correlações dos percentuais de ocorrências com os elementos meteorológicas de superfície (temperatura do ar e pressão atmosférica), extraídas de observações meteorológicas horárias da localidade em estudo. Os resultados mostram, que nos últimos anos, a ocorrência de rajada de vento no aeródromo de Belém-Pa, vem aumentando, onde o maior registro dessa ocorrência dentro do período foi no ano de 2012. A maior frequência de eventos de rajada por intervalos de velocidade foi de 21 a 30 KT. A maior distribuição sazonal do registro de rajadas de vento ocorreu no período mais chuvoso da região, dezembro a maio, influenciadas pela nebulosidade, formada no Oceano Atlântico Equatorial, devido a atuação da ZCIT. As maiores quantidades de registros de rajadas de ventos correspondem ao período de máximas temperaturas, sugerindo uma correlação entre o aquecimento e a ocorrência de rajadas próximas a superfície terrestre. A distribuição de rajada de vento, de acordo com a orientação do vento indica predominância dos ventos de leste, de 60º a 120º. ABSTRACT This paper aimed to study the wind occurrence frequency and its importance on the safety of flight operations, since these are significant variations in wind intensity, causing many risks to aviation, from discomfort during flight to even loss of lifes. The data were obtained from the International Aerodrome of Belém do Pará, in the period from 2009 to 2012, where statistical analyzes were performed, as well as studies of correlations of the percentage of occurrences with surface meteorological elements (air temperature and atmospheric pressure), extracted from hourly meteorological observations from the study site. The results show that in recent years, the occurrence of gust of wind at the airfield of Belém-Pa, is increasing, where the highest record of this occurrence within the period was in 2012. The higher frequency of events per burst speed intervals was 21-30 KT. The largest seasonal distribution record wind gusts occurred in the rainy season in the region, from December to May, influenced by clouds formed in the Equatorial Atlantic Ocean, due to tripping of the ITCZ. The largest amounts of records gusty winds correspond to the period of maximum temperatures, suggesting a correlation between warming and the occurrence of near Earth's surface bursts. The distribution of wind, according to the orientation of the wind indicates predominance of winds east 60 º to 120 º. Keywords: Wind direction, air temperature, atmospheric pressure.
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Le, Khang Duy Ricky. "Cognitive Simulation Using Mental Rehearsal for Procedural Learning in Medical Students: A Narrative Review". Journal of Medical Education and Curricular Development 12 (janeiro de 2025). https://doi.org/10.1177/23821205251313728.
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Mental rehearsal, defined as the deliberate cognitive rehearsal of tasks without action, is an emerging approach to procedural skills learning in healthcare education. In particular, mental rehearsal has been associated with durable improvement of complex skills in various fields such as aviation, high performance sports and surgery. Despite this, mental rehearsal-based practices in healthcare are challenged with mainly informal and highly heterogeneous practice. Given this, the efficacy of mental rehearsal in medical education remains poorly characterised. Furthermore, there is currently no evidence-based approach to integrating mental rehearsal in the medical curriculum, nor frameworks to guide development of mental rehearsal skills for students. This narrative review explores mental rehearsal in medical education and evaluates the current principles of mental rehearsal and how these can be applied to improve procedural skills learning for medical students.
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Parten, Clay, Balakrishnan Subeshan e Ramazan Asmatulu. "Highly conductive and durable nanocomposite hard coatings of carbon fiber reinforced thermoplastic composites against lightning strikes". Discover Nano 19, n.º 1 (6 de junho de 2024). http://dx.doi.org/10.1186/s11671-024-04041-5.
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AbstractThe growing use of thermoplastic composites (TPCs) like low-melting polyaryletherketone (LM-PAEK) matrices reinforced with unidirectional carbon fiber (CF) in aircraft structures presents a significant challenge in terms of lightning strikes and electromagnetic interference shielding during aircraft operations. This is due to the weak electrical conductivity of TPC structures, which results in widespread damage when struck by lightning. The repair and maintenance of these extended damaged sites can increase operational costs and loss of flights. Several lightning strike protection (LSP) systems have been developed and implemented to address these concerns. This study evaluated a highly conductive coating with a low filler rate for its effectiveness as an LSP solution for TPCs on exterior aircraft surfaces. The TPC panel without any coatings was first studied. Subsequently, the level of conductivity was increased by incorporating the nanoscale conductive fillers, silver-coated copper (Ag/Cu) nanoflakes, with a silver content of 20 wt.% (Ag20/Cu) and 30 wt.% (Ag30/Cu), correspondingly, into the coating at two loadings of 55 wt.% and 70 wt.% in an epoxy carrier for the surface coatings. The behavior of electrical and surface conductivity was thoroughly examined to understand the impact of Ag/Cu with a high aspect ratio and the effectiveness of the LSP solution. In addition, the spray-coated TPC panels underwent rigorous Zone 2A lightning strike testing using simulated lightning current, in agreement with the industry standard of Society of Automotive Engineers (SAE) Aerospace Recommended Practice (ARP) 5412B. Despite the higher resistance due to the lower conductive coating weight, the TPC panels with Ag30/Cu at loading of 70 wt.% achieved better results than those with Ag30/Cu at loading of 55 wt.%. This is evidenced by the minor structural delamination and CF breakage on the front surface, which proposes a new economic route for a sustainable post-processed LSP system in the aviation industry.
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Kaboglu, Cihan, Taha Yasin Eken e Sukran Guney. "Effect of curvature and stacking sequence on flexural strength in glass fiber reinforced composites". Materials Testing, 20 de junho de 2023. http://dx.doi.org/10.1515/mt-2022-0348.
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Abstract Most of the structures in vehicles used in the automotive, aviation, and marine industries are exposed to different loads. It is seen that these structures are more exposed to flexural stress. Structures can sustain dangerous damage over time under the effects of flexural loads. The resistance of curved glass fiber reinforced polymer composites to flexural force is very important. In this study, the diameters of curved composites of 760 mm, 380 mm, and 304 mm are studied. Also, fiber stacking sequences were determined as [0/0/−45/+45/90/90]S and [90/90/−45/+45/0/0]S and compared. All specimens were produced by vacuum infusion method. Three-point flexural tests were performed according to the ASTM D7264 standard at 1 mm∙min−1 punch speed. Among all composites, 760 mm diameter and Type 2 stacking were found to have the highest flexural strength. Hence, it was observed that the flexural strength decreased with the increase in curvature, and Type 2 fiber layer sequencing is more durable than Type 1 sequencing. This is because the 90° fiber direction in the substrate has a damping effect on the applied force.
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Calverley, M. A. A. "THE DESIGN OF BRITISH AIRPORTS AUTHORITY PAVEMENTS". Proceedings of the International Conference on Concrete Pavements, 4 de janeiro de 2025. https://doi.org/10.33593/iccp.v1i1.1213.
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The article "The Design of British Airports Authority Pavements" by M.A.A. Calverley provides a comprehensive overview of pavement design and maintenance practices utilized by the British Airports Authority (BAA) across its seven major UK airports. This detailed examination covers the development, planning, design, and construction of new pavements and the maintenance of existing ones, with a focus on meeting or exceeding the standards set by the UK Civil Aviation Authority and international guidelines from ICAO. The paper highlights the adaptation of the Load Classification Group (LCG) system which incorporates modified Load Classification Numbers (LCN) to assess and design pavement strength based on aircraft weight and configuration, and the evolution of this system to accommodate increasing aircraft loads and ensure safety. The design strategies discussed include the use of Portland cement for rigid pavements due to its cost-effectiveness and durability compared to flexible pavement options. The document also discusses the operational challenges and environmental considerations at the BAA managed airports, emphasizing the need for pavements that are economical, durable, and minimally disruptive during maintenance. The approach taken by BAA not only ensures compliance with stringent safety and operational standards but also adapits to the ongoing changes in aircraft technology and airport operations. (Abstract generated by AI tool ChatGPT 4)
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Karaca, Muhammet Mevlüt, Safa Polat e İsmail Esen. "Reciprocating dry sliding wear behaviour of BN@MXene@AA7075 composites". Journal of Composite Materials, 27 de maio de 2024. http://dx.doi.org/10.1177/00219983241257665.
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Aluminium alloys are preferred in various fields, especially in the aviation and automotive sectors, due to their lightweight and durable nature. However, their usage is limited due to weak tribological properties such as low hardness and high adhesion tendency against steel. In order to overcome this deficiency, this study aimed to develop AA7075 matrix composites reinforced with BN and MXene. The productions were conducted by powder metallurgy method with these reinforcements in different ratios, both together and separately. The produced composites were characterized primarily by XRD and SEM analyses, followed by measurement of density and porosity values. Wear tests were conducted using the reciprocating ball-on-flat method, at a frequency of 3 Hz, a sliding distance of 100 m, and a stroke distance of 5 mm, with Inox steel ball. The highest improvement in wear rate was realized under 5 N load at 5 wt.% reinforcement ratios of 48% and 42% for BN and MXene, respectively. When 2 wt% BN and MXene reinforcements were applied together, the improvement rate remained around 34%. It can be said that BN and MXene show promising results by providing significant improvements compared to their counterparts in the literature, with MXene especially warranting further investigation.
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Memmolo, Vittorio, Leandro Maio, Ernesto Monaco, Fabrizio Ricci, Veronica Vespini, Fabiana Graziano, Simonetta Grilli, Sara Coppola e Pietro Ferraro. "Non-destructive evaluation and Structural Health Monitoring of impact induced damage in composite structures using ultrasonic approaches and shearography". e-Journal of Nondestructive Testing 29, n.º 7 (julho de 2024). http://dx.doi.org/10.58286/29854.
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Composite structures are massively used thanks to the high strength-to-weight ratio, making them ideal for lightweight and durable structures in aviation. However, Impact may arise at any time during lifetime on composite aerostructures and ensuring their structural integrity via fast inspection is essential to meet airworthiness criteria. Multimodal NDT (Non-Destructive Testing) inspection and characterization of composite structures is a critical process to verify the quality of the composite material and identify any defects. In this context, the paper shows a comparison of several techniques as nondestructive methods: shearography, laser ultrasonics and phased array ultrasonics. In particular, using shearography and laser ultrasonics as non-contact approaches can increase the inspection speed and reliability compared to the state of the art phased array ultrasonics, which is the standard approach used in the aerospace field. For this reason, a sample of interest to the aerospace industry is subject to different low velocity impacts which are characterized by different energies leading to barely visible damage. The results show the capabilities of both approaches in identifying small emerging defects along with the advantage and drawbacks of both methodologies through a critical review of performance thereof evaluating the parameters of their use. In addition, the same approaches are adopted on a stiffener composite plates and compared with continuous health monitoring approaches. In this regard, NDT approaches are demonstrated useful to enhance the SHM warnings.