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1. Dielectrophoresis of air

   https://doi.org/10.1063/5.0002286  

   Soffer, Lucas; Rendos, Abigail; Zosuls, Aleksandrs L.; Walsh, Brian M.; Brown, Keith A. (February 2020, Applied Physics Letters)
2. Evaluation of Neural Network Verification Methods for Air-to-Air Collision Avoidance

   https://doi.org/10.2514/1.D0255  

   Manzanas Lopez, Diego; Johnson, Taylor T.; Bak, Stanley; Tran, Hoang-Dung; Hobbs, Kerianne L. (January 2023, Journal of Air Transportation)

   Neural network approximations have become attractive to compress data for automation and autonomy algorithms for use on storage-limited and processing-limited aerospace hardware. However, unless these neural network approximations can be exhaustively verified to be safe, they cannot be certified for use on aircraft. An example of such systems is the unmanned Airborne Collision Avoidance System (ACAS) Xu, which is a very popular benchmark for open-loop neural network control system verification tools. This paper proposes a new closed-loop extension of this benchmark, which consists of a set of 10 closed-loop properties selected to evaluate the safety of an ownship aircraft in the presence of a co-altitude intruder aircraft. These closed-loop safety properties are used to evaluate five of the 45 neural networks that comprise the ACAS Xu benchmark (corresponding to co-altitude cases) as well as the switching logic between the five neural networks. The combination of nonlinear dynamics and switching between five neural networks is a challenging verification task accomplished with star-set reachability methods in two verification tools. The safety of the ownship aircraft under initial position uncertainty is guaranteed in every scenario proposed. 

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3. High Performance Air Breathing Flexible Lithium–Air Battery

   https://doi.org/10.1002/smll.202102072  

   Ahmad Jaradat, Chengji Zhang (January 2021, Small)

   null (Ed.)

   Lithium–oxygen (Li–O2) batteries possess the highest theoretical energy density (3500 Wh kg−1), which makes them attractive candidates for modern electronics and transportation applications. In this work, an inexpensive, flexible, and wearable Li–O2 battery based on the bifunctional redox mediator of InBr3, MoS2 cathode catalyst, and Fomblin-based oxygen permeable membrane that enable long-cycle-life operation of the battery in pure oxygen, dry air, and ambient air is designed, fabricated, and tested. The battery operates in ambient air with an open system air-breathing architecture and exhibits excellent cycling up to 240 at the high current density of 1 A g−1 with a relative humidity of 75%. The electrochemical performance of the battery including deep-discharge capacity, and rate capability remains almost identical after 1000 cycle in a bending fatigue test. This finding opens a new direction for utilizing high performance Li–O2 batteries for applications in the field of flexible and wearable electronics. 

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4. Effect of Antenna Orientation on the Air-to-Air Channel in Arbitrary 3D Space

   https://doi.org/10.1109/WoWMoM51794.2021.00055  

   Matson, N. Cameron; Hashir, Syed Muhammad; Song, Sicheng; Rajan, Dinesh; Camp, Joseph (June 2021, 2021 IEEE 22nd International Symposium on a World of Wireless, Mobile and Multimedia Networks (WoWMoM))

   null (Ed.)

   Unmanned Aerial Vehicles (UAVs) often lack the size, weight, and power to support large antenna arrays or a large number of radio chains. Despite such limitations, emerging applications that require the use of swarms, where UAVs form a pattern and coordinate towards a common goal, must have the capability to transmit in any direction in three-dimensional (3D) space from moment to moment. In this work, we design a measurement study to evaluate the role of antenna polarization diversity on UAV systems communicating in arbitrary 3D space. To do so, we construct flight patterns where one transmitting UAV is hovering at a high altitude (80 m) and a receiving UAV hovers at 114 different positions that span 3D space at a radial distance of approximately 20 m along equally-spaced elevation and azimuth angles. To understand the role of diverse antenna polarizations, both UAVs have a horizontally-mounted antenna and a vertically-mounted antenna-each attached to a dedicated radio chain-creating four wireless channels. With this measurement campaign, we seek to understand how to optimally select an antenna orientation and quantify the gains in such selections. 

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5. Modeling air-to-air plate-fin heat exchanger without dehumidification

   https://doi.org/10.1016/j.applthermaleng.2018.07.064  

   Zhou, G.; Ye, Y.; Wang, J.; Zuo, W.; Fu, Y.; Zhou, X. (October 2018, Applied Thermal Engineering)