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An Introduction to Seabirds and Their Study
Published in Jaime A. Ramos, Leonel Pereira, Seabird Biodiversity and Human Activities, 2022
Marie Claire Gatt, José Pedro Granadeiro, Paulo Catry
Procellariiformes also show extra-tropical peaks in species richness and are asymmetrically distributed, with far higher diversity in southern high latitudes than in northern ones. The reduced energy expenditure of dynamic soaring in many procellariiforme species allows them to capitalise on patchily distributed resources over large distances (Lack 1968, Ashmole 1971). Wind speeds are highest at high latitudes, but are also higher and more constant in the southern hemisphere, where there is more contiguous ocean with fewer land barriers compared to the northern hemisphere. Both the available wind energy and the expanse of open ocean increase the potential for long-distance foraging trips to highly productive areas (Weimerskirch et al. 2000, Shaffer et al. 2001), and may partially explain the spatial distribution of species richness in this order (Davies et al. 2010).
Biomechanics and Biomimetics in Flying and Swimming
Published in Akihiro Miyauchi, Masatsugu Shimomura, Industrial Biomimetics, 2019
Hao Liu, Toshiyuki Nakata, Gen Li, Dmitry Kolomenskiy
As the body orientation changes, the vertical projection of the aerodynamic force becomes smaller. The aerodynamic force magnitude has to be consistently increased to maintain level flight. This is achieved by increasing the wingbeat frequency or amplitude or both [140, 152, 142, 40]. The increase comes at an added energetic cost, as the aerodynamic power required for flight grows roughly quadratically with the roll amplitude [99]. This cost can possibly be offset if the body posture is stabilized using asymmetric time variation of such kinematic parameters as the stroke amplitude, stroke plane angle, and feathering rotation angle. Yet, the energetic efficiency and limitations of these control strategies when applied to flight through turbulence need to be quantified. Apart from flapping flight, gliding is another mode of aerial locomotion likely to be affected by turbulence. Migrating birds, for instance, use thermal soaring to gain height, while minimizing the energy cost of propulsion. Thermals are ascending currents driven by the temperature gradient and inevitably producing strong turbulent fluctuations. Reddy et al. [154] explored the thermal soaring strategies optimal to different levels of atmospheric turbulence intensity using numerical models. The study combined numerical simulations of atmospheric flow with reinforcement learning methods. It showed that the optimal soaring strategies varied as the magnitude of turbulent fluctuations increased. In the regimes of weak turbulence, exploratory strategies were preferred, whereas in the regimes of strong turbulence, the optimal strategies were more risk-averse such as to reduce the probability of dramatic losses of height.
A Search for Meaning: A Case Study of the Approach-to-Landing
Published in Erik Hollnagel, Handbook of Cognitive Task Design, 2003
John M. Flach, Paul F. Jacques, Darby L. Patrick, Matthijs Amelink, M. M. (Rene) Van Paassen, Max Mulder
The Wrights engineered the system around the control problem. They focused their efforts on designing "a control system that an airborne pilot could operate." They succeeded because they engineered a system that allowed manipulation of the flight surfaces. Perhaps the most significant contribution was the invention of "wing-warping" to aid in balance and control. Freedman (1991) noted that the insight for wing-warping began with observations of "buzzards gliding and soaring in the skies over Dayton, they noticed that the birds kept adjusting the positions of their outstretched wings. First one wing was high, then the other" (p. 29). Freedman (1991) continued as follows:
Entropy generation analysis and cooling time estimation of a blast furnace in natural convection environment
Published in Numerical Heat Transfer, Part A: Applications, 2022
Shafiq Mohamad, Sachindra Kumar Rout, Jnana Ranjan Senapati, Sunil Kumar Sarangi
Figure 11 illustrates the contours of static temperature on the whole cylindrical surface for several values of Rayleigh number at T* = 1.5 and L/D = 3.24. Due to the buoyancy effect in natural convection, the thermal plumes move in the vertical direction. When Ra = 10+4, there is an observable region of higher temperature adjacent to the cylindrical surface. There is an inverse relationship between the temperature near the surface and the Rayleigh number. So as the Rayleigh number shoots up, the temperature near the surface decreases gradually. Moreover, the intensity of free convection escalates as the Rayleigh number soars. As a result, the thickness of the thermal boundary layer diminishes with the soaring of the Rayleigh number. Furthermore, the temperature within the high-temperature region has a uniform distribution on the surface of the cylinder.
Advances in bio-logging techniques and their application to study navigation in wild seabirds
Published in Advanced Robotics, 2019
Heading vectors of birds and wind vectors were simultaneously modeled and estimated from positional data recorded using animal-borne GPS loggers [85]. The estimated parameters showed that homing shearwaters could head in a direction different from that leading directly to the colony, to offset wind effects, whilst their overall movement took them in the direction of the colony. Streaked shearwaters adopt a dynamic soaring flight, in which their heading direction changes continuously within the scale of a few seconds. Thus, the shearwaters evaluate the wind conditions they experience, and control their flight direction during dynamic soaring, resulting in an optimal navigation course toward their goal on a large spatial scale.