The emissions from in-use commercial aircraft engines have been analyzed for selected gas-phase species and particulate characteristics using continuous extractive sampling 1-2 min downwind from operational taxi- and runways at Hartsfield-Jackson Atlanta International Airport. Using the aircraft tail numbers, 376 plumes were associated with specific engine models. In general, for takeoff plumes...

In the present paper, the controlled flight of fruitflies after voluntary takeoff is studied. Wing and body kinematics of the insects after takeoff are measured using high-speed video techniques, and the aerodynamic force and moment are calculated by the computational fluid dynamics method based on the measured data. How the control moments are generated is analyzed by correlating the computed ...

Combustion-based sources of shaft power tend to significantly penalize distributed propulsion concepts, but electric motors represent an opportunity to advance the use of integrated distributed propulsion on an aircraft. This enables use of propellers in nontraditional, non-thrust-centric applications, including wing lift augmentation, through propeller slipstream acceleration from distributed ...

Acceleration is of great importance in motion control for unmanned aerial vehicles (UAVs), especially during the takeoff and landing stages. However, the measured acceleration is inevitably polluted by severe noise. Therefore, a proper noise suppression procedure is required. This paper presents a novel method to reduce the noise in the measured vertical acceleration for a thrust-vectored tail-...

Compared to other species of tamarins and marmosets, callimicos (Callimico goeldii) are characterized by hindlimb and hindfoot elongation, and a pattern of locomotion dominated by leaping to and from vertical supports in the forest understory. We present field data on trunk-to-trunk leaping in a habituated group of callimicos in northern Bolivia. We measured the DBH of the takeoff and landing p...

Countermovement and arm-swing characterize most jumping. For determination of their effects and interaction, 18 males jumped for maximal height from a force platform in all four combinations of arm-swing/no-arm-swing and countermovement/no-countermovement. For all jumps, vertical velocity peaked 0.03 s before and dropped 6-7% by takeoff. Peak positive power averaged over 3,000 W, and occurred a...

Sales in a new market generally follow a hockey-stick pattern: after commercialization, sales are very low for some time before there is a dramatic “takeoff” in growth. Reported sales takeoffs across products vary widely from a few years to several decades. Prior research identifies new firm entry or price declines as key factors that relate to the timing of a sales takeoff in new markets. Howe...

A critical role of functional morphology is to demonstrate form-function relationships that can then be used by evolutionary biologists to infer the evolutionary history of the structure in question. Tests of theoretical expectations about the effects of many aspects of morphology/physiology on locomotor performance have had very mixed results. If systems such as jumping can be shown to reliabl...

This is a joint thermodynamicand acoustic study of engines for next-generation supersonic aircraft. It explores Ž xed-cycle concepts with potential for quiet takeoff and efŽ cient cruise. The  owpath is simple, withoutmechanical suppressors.The strategy is to takearepresentative state-of-the-artmilitary turbofanengineandincrease its bypass ratio to a moderate value. The engine core stays the s...

The goal of a safety management system is to monitor sensors, identify hazards and mitigate risk to the extent possible. In this paper, we present a novel approach called Flight Safety Assessment and Management (FSAM) to assess key quantitative and qualitative feedback parameters for loss of control (LOC) risk. Decision making logic is specified as a set of hierarchical timed automata models. L...