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Emerging Trends in Urban Air Mobility: An Extensive Review
Get PDFThis paper presents a review of the main trends in the urban air mobility (UAM) sector. After an initial introduction to the key aspects driving the design of aircraft for this type of application and the main characteristics of each type of aircraft developed so far, the focus shifts to the description of the main regulatory frameworks, highlighting the essential requirements that the aircraft must meet at each stage of flight. To translate the aircraft or propeller requirements into design specifications for electric motors, an aerodynamic model is presented. Subsequently, a series of aircraft developed by major industry players is described. In the following section, the key characteristics sought in motors for UAM are outlined, along with various examples of motors developed by leading companies. Additionally, specific design considerations and recommendations are discussed, emphasizing critical aspects such as the adoption of advanced conductors and high-performance cooling systems to enhance power density and efficiency. In conclusion, this review highlights the diverse UAM designs shaping a technological shift in aviation. As prototypes evolve, greater standardization will drive industry growth and support the broader ecosystem, including vertiport providers
Multi-layer Abstraction for Nested Generation of Options (MANGO) in Hierarchical Reinforcement Learning
No full textUnderstanding the Role of Superhydrophobicity on Heat Transfer Enhancement During Dropwise Condensation in Humid Air Flow
No full textSuperhydrophobic surfaces have been extensively studied to enhance heat transfer during moisture condensation. However, the existing literature presents conflicting results, with some studies reporting enhanced performance while others observe a decline compared to hydrophilic surfaces. Furthermore, the effect of air velocity has been marginally addressed. In this work, superhydrophobic aluminum surfaces (advancing contact angle of 160°, contact angle hysteresis <1°) are fabricated by chemical etching followed by fluorosilane coating. Condensation tests are performed at constant air temperature (28 °C), while varying relative humidity (70%, 90%), dew-to-wall temperature difference (7–13 K) and air velocity (0.4–6 m s−1). It is found that, compared to the hydrophilic untreated surface, superhydrophobic surfaces do not offer any advantage at low air velocities (0.4 and 1 m s−1), while a condensation heat transfer coefficient increased by 30%–40% is achieved at high air velocities (4 and 6 m s−1). The performance is attributed to a more efficient droplet removal mechanism and enhanced vapor mass transfer through the non-condensable gas layer, which is also associated with droplet-induced vorticity, as confirmed by video analysis. The results clarify the operating conditions under which superhydrophobic surfaces are advantageous for applications of condensation from humid air, including dehumidification
Cu-Catalyzed Asymmetric Olefinative Conjugate Addition of Aryl and Alkenyl Boronic Esters
No full textThe asymmetric olefinative conjugate addition (AOCA) has been previously introduced as a telescoped approach for the synthesis of chiral internal olefins with high stereoselectivities. Here, this strategy is extended by the implementation of aryl and alkenyl boronic esters as C(sp2) nucleophiles, thus notably expanding the range of accessible products by the AOCA. A variety of relatively complex chiral products are reported, which were obtained in high yields, diastereoselectivities, and enantioselectivities up to 97:3 er. These include dienes and trienes that are otherwise difficult to access in a single step
Restorative psychophysiological effects of biophilic virtual environment
No full textBiophilic design incorporates nature into built environments, creating restorative spaces that enhance health and
well-being. This study explored the effects of virtual reality (VR) environments with different levels of biophilic
properties on affective and psychophysiological states, perceived restorativeness, and the affective qualities of
places. One hundred fifty young adults (87 female) completed a stress-inducing task before being assigned to VR
conditions: Bio.Pod, Bio.Pod with a Nature View, or control (work-brake room). Psychophysiological measures
(heart rate and skin conductance), affective states, perceived restorativeness, and the affective qualities of places
were evaluated. VR environments influenced emotional states (increased valence, reduced arousal) and reduced
negative and positive affect. Both Bio.Pod conditions reduced physiological arousal, were perceived more
restorative and had more positive affective qualities than the control, whereas cardiac activity was slower in Bio.
Pod with Nature View. These findings highlight the potential of biophilic VR environments in promoting psychophysiological stress recovery and well-being
Controller for Grid-Current Regulation and RMS Current Reduction of a Matrix-Type Converter
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Hypertrophic cardiomyopathy and atrial fibrillation: The Cardiomyopathy/Myocarditis Registry of the EURObservational Research Programme of the European Society of Cardiology
No full textBackground Hypertrophic cardiomyopathy (HCM) is commonly associated with atrial fibrillation (AF), but its impact on outcomes in real-world practice is uncertain. The aim of the study was to evaluate the clinical profile and prognosis of patients with HCM and AF. Methods Overall, 1739 adult patients with HCM (40.9% women; median age: 55.5 years) were enrolled in the EURObservational Research Programme (EORP) Cardiomyopathy/Myocarditis Registry. Clinical characteristics at baseline and cardiovascular endpoints at 1 year were prospectively assessed. Results At baseline, AF was present in 478 (27.5%) patients; an additional 48 patients (2.8%) developed AF at 1-year follow-up. Oral anticoagulants (OAC) were administered at baseline in 69.5% of the patients. Patients with AF were older and more symptomatic, had higher body mass index, more prevalent cardiovascular risk factors, a history of sustained ventricular tachycardia and implantable cardioverter-defibrillator, lower left ventricular ejection fraction (LVEF), larger left atria (LA) and more advanced LV diastolic dysfunction (pp<0.001 for all). Age at enrolment (OR=1.068, p<0.001), symptom: palpitations (OR=2.191, p<0.001), LVEF (OR=0.978, p<0.001) and LA diameter (OR=1.094, p<0.001) were independent predictors of AF in HCM population. Patients with AF had a higher annual incidence of stroke/transient ischaemic attack (2.6 vs 0.9%, p=0.009) and a trend towards increased all-cause mortality in comparison to the non-AF cohort (3.4 vs 1.7%, p=0.053). Conclusions AF affects nearly one-third of patients with HCM and is associated with higher symptom burden, increased prevalence of comorbidities, myocardial remodelling and increased annual risk of cerebral ischaemic events. In spite of this, the utilisation of OAC was suboptimal
Design of the Sensing Elements of LD-GRIDS, a Charged Dust Analyser for Lunar Surface in the EMM Project Framework
No full textLunar dust's electrostatic behaviour threatens the safety and longevity of lunar missions, particularly as NASA's Artemis program advances toward sustained human exploration. This study aims to compare two different configurations for the sensing elements of LD GRIDS (Lunar Dust Grid System) (square and round patterns), a dust analyser conceived to measure charged particles on the next Moon missions. The interaction between the charged particle and sensing elements is simulated by using COMSOL Multiphysics software. The work focuses on two objectives: (1) validating a numerical model against the foundational results of literature and (2) advancing sensor design by comparing the expected performance through a grid-based electrode system. The developed model agreed well with the literature, providing discrepancies on the induced charge below 6%. Moreover, starting from the geometry described in previous studies, aimed to assess the feasibility of charge dust analysers to cope with general space mechanical environment, the LD GRIDS grid-based designs were tested for charge induction performance as particles traversed single and paired grid arrangements. Comparison of the obtained results allowed for the identification of the optimal instrument configuration
