The integration of Remotely Piloted Vehicles (RPVs) into civil airspace will require new methods of ensuring traffic avoidance. This paper discusses issues affecting requirements for RPV traffic avoidance systems and describes the safety evaluation process that the international community has deemed necessary to certify such systems. Alternative methods for RPVs to perform traffic avoidance are discussed, including the potential use of new seeand-avoid sensors or the Traffic Alert and Collision Avoidance System (TCAS). Concerns that must be addressed to allow the use of TCAS on RPVs are presented. The paper then details the safety evaluation process that is being implemented to evaluate the safety of TCAS on Global Hawk. The same evaluation process can be extended to other RPVs and traffic avoidance systems for which thorough safety analyses will also be required.

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The integration of Remotely Piloted Vehicles (RF'Vs) into civil airspace will require new methods of ensuring aircraft separation. This paper discusses issues affecting requirements for RF' V traffic avoidance systems and for performing the safety evaluations that will be necessary to certify such systems. The paper outlines current ways in which traffic avoidance is assured depending on the type of airspace and type of traffic that is encountered. Altemative methods for RPVs to perform traffic avoidance are discussed, including the potential use of new see-and-avoid sensors or the Traffic Alert and Collision Avoidance System (TCAS). Finally, the paper outlines an established safety evaluation process that can be adapted to assure regulatory authorities that RPVs meet level of safety requirements.

NiMo (nickel-molybdenum) and NiMo with embedded CeO2 nanoparticles (NPs; 100 nm) were tested as antimicrobial coatings (~15 μm thickness) on titanium (Ti) surfaces using an electrochemical process for heat exchanger applications onboard marine vessels. Preliminary static biofouling and biocorrosion (also known as microbiologically influenced corrosion) assessments were carried out in glass bottles using pure-culture Desulfovibrio vulgaris, a sulfate-reducing bacterium (SRB), in deoxygenated ATCC 1249 medium at 37°C, and using an alga (Chlorella vulgaris) mixed with general heterotrophic bacteria (GHB) in enriched artificial seawater at 28°C. It was found that the coating containing NiMo/CeO2 NPs were much more effective than NiMo in preventing SRB biofilm formation with an efficacy of 99% reduction in D. vulgaris sessile cells after 21 day incubation. The coating also exhibited a 50% lower corrosion current density compared to the uncoated Ti against SRB corrosion. Both NiMo and NiMo/CeO2 NP coatings achieved 99% reduction in sessile algal cells. Confocal laser scanning microscopy (CLSM) biofilm images indicated a large reduction of sessile GHB cells. The CLSM images also confirmed the biocidal kill effects of the two coatings. Unlike polymer coatings, the “metallic” coatings are heat conductive. Thus, the corrosion resistant antifouling coatings are suitable for heat exchanger applications.

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