Abstract: Embodiments of the present disclosure describe a secure, scalable and extensible aircraft and other system and device identity management (IdM) system that enables services for identity provisioning (idP), and identity validation, verification and authentication (idVV&A). The identity and management system uses dual-mode local broadcast and network connected device communication elements across a wide area network. The system serves as a Source System of Record (SSoR) that securely ingests private registration data, system/device identity verification and authentication requests and returns validated identity and activity information.

Abstract: Embodiments of the present disclosure describe a secure, scalable and extensible unmanned aircraft system identity management (IdM) system that enables services for identity provisioning (idP), and identity validation, verification and authentication (idVV&A). The system uses dual-mode local broadcast and network connected UAS communication elements across a wide area network. The system serves as a Source System of Record (SSoR) that securely ingests private registration data, UAS identity verification and authentication requests and returns validated identity and flight information.

Abstract: An exhaust duct assembly for conveying exhaust gases emanating from a combustion zone to atmosphere is disclosed. The assembly includes: an exhaust gas outlet for exhausting exhaust gas into the atmosphere; and an acoustic duct portion located upstream of the exhaust gas outlet, the acoustic duct portion having a peripheral wall defining a through-passage arranged and constructed to promote propagation of sound there-through. The acoustic duct portion has a length in a flow direction that is at least 50% of an average hydraulic diameter of the through-passage.

Abstract: A device (40, 50) for reducing noise levels in passenger conveyor systems (10) at least partially obstructs spacing (36) at the interface between two steps (24, 30) to allow for relative movement between one step and the next. A sound transmission reducing member (40, 50) at least partially obstructs a sound pathway that includes the spacing to reduce the transmission of noise through the spacing. The sound transmission reducing member in one example is a barrier that partially blocks the interface, while in another, it extends completely across the interface. Additionally, sound absorbing material (46) may be secured to the underside of the steps in order to further reduce sound transmission toward the passengers and individuals near the conveyer.