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1. Coarse sea spray inhibits lightning

   https://doi.org/10.1038/s41467-022-31714-5  

   Pan, Zengxin; Mao, Feiyue; Rosenfeld, Daniel; Zhu, Yannian; Zang, Lin; Lu, Xin; Thornton, Joel A.; Holzworth, Robert H.; Yin, Jianhua; Efraim, Avichay; et al (August 2022, Nature Communications)

   Abstract The known effects of thermodynamics and aerosols can well explain the thunderstorm activity over land, but fail over oceans. Here, tracking the full lifecycle of tropical deep convective cloud clusters shows that adding fine aerosols significantly increases the lightning density for a given rainfall amount over both ocean and land. In contrast, adding coarse sea salt (dry radius > 1 μm), known as sea spray, weakens the cloud vigor and lightning by producing fewer but larger cloud drops, which accelerate warm rain at the expense of mixed-phase precipitation. Adding coarse sea spray can reduce the lightning by 90% regardless of fine aerosol loading. These findings reconcile long outstanding questions about the differences between continental and marine thunderstorms, and help to understand lightning and underlying aerosol-cloud-precipitation interaction mechanisms and their climatic effects. 

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2. Experimental Spray Characterization for Jet-A1 Under Temperature Controlled Subcritical, Transcritical, and Supercritical Spray Conditions

   Nonavinakere Vinod, Kaushik; Kempin, Robert; Fang, Tiegang (May 2023, Proceedings of 14th Asia-Pacific Conference on Combustion)

   Fuels when sprayed under superheated and elevated fuel pressure show different behavior than traditional fuel injection sprays. In this work optical diagnostics were used to study the behavior of Jet A-1 under subcritical, transcritical, and supercritical sprays into open air ambience. Five different temperatures were tested, and the resultant spray images were processed to obtain quantitative measurements such as spray penetrations, and spray cone angle for each case. The spray structure transition with changing parameters from subcritical, transcritical, and supercritical states were also studied. The transition between the three different states are shown in this study and the resulting spray cone angles and penetrations are compared for the fuel. The results show that a transcritical spray has a measurable variation in the spray cone formation and penetration process for a fixed injection pressure. At this state the spray cone shows a bimodal spray angle relationship with increasing penetration. Flash boiling of the fuel is observed near the nozzle of the injector. Increasing the temperature further into the supercritical regime, the spray plume shows a thinning of the jet near the nozzle with a reduced overall penetration compared to lower temperatures. 

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3. Spray Mechanism of Contained-Electrospray Ionization

   https://doi.org/10.1021/jasms.0c00044  

   Miller, Colbert F.; Burris, Benjamin J.; Badu-Tawiah, Abraham K. (January 2020, Journal of the American Society for Mass Spectrometry)

   Analytical characteristics of contained electrospray ionization (ESI) are summarized in terms of its potential to modify the analyte solution during the stages of droplet formation to provide opportunities to generate native versus denatured biomolecular gas-phase ions, without the need for bulk-phase analyte modifications. The real-time modification of the charged microdroplets occurs in a cavity that is included in the outlet of the contained-ESI ion source. Close examination of the inside of the cavity using a high-speed camera revealed the formation of discrete droplets as well as thin liquid films in the droplets wake. When operated at 20 psi N2 pressure, the droplets were observed to move at an average speed of 8 mm/s providing ∼1 s mixing time in a 10 mm cavity length. Evidence is provided for the presence of highly reactive charged droplets based on myoglobin charge state distribution, apo-myoglobin contents, and ion mobility drift time profiles under different spray conditions. Mechanistic insights for the capture of vapor-phase reagents and droplet dynamics as influenced by different operational modes are also described. 

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4. Helium assisted desorption and spray ionization

   https://doi.org/10.1016/j.ijms.2022.116891  

   Javanshad, Roshan; Panth, Rajendra; Maser, Tara L.; Venter, Andre R. (September 2022, International Journal of Mass Spectrometry)
5. Spray Generation by a Plunging Breaker

   https://doi.org/10.1029/2019GL082831  

   Erinin, M. A.; Wang, S. D.; Liu, R.; Towle, D.; Liu, X.; Duncan, J. H. (July 2019, Geophysical Research Letters)

   Abstract An experimental investigation of droplet generation by a plunging breaking wave is presented. In this work, simultaneous measurements of the wave crest profile evolution and of droplets ranging in radius down to 50 μm for a mechanically generated plunging breaker during many repeated breaking events in freshwater are performed. We find three distinct time zones of droplet production, first when the jet impacts the free surface upstream of the wave crest, second when the large air bubbles entrapped by the plunging jet impact reach the free surface and burst, and third when smaller bubbles burst upon reaching the free surface later in the breaking process. These subprocesses account for 22%, 44%, and 34%, respectively, of the average of 653 droplets produced per breaking event. The probability distributions of the ranges of large and small droplet radii are well represented by power law functions that intersect at a radius of 418 μm. 

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