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Initial orientation of homing pigeons at the magnetic equator with and without sun compass

Behavioral Ecology and Sociobiology ◽

10.1007/bf00366659 ◽

1983 ◽

Vol 14 (1) ◽

pp. 77-79 ◽

Cited By ~ 7

Author(s):

R. Ranvaud ◽

K. Schmidt-Koenig ◽

J. Kiepenheuer ◽

O. C. Gasparotto

Keyword(s):

Initial Orientation ◽

Magnetic Equator ◽

Sun Compass ◽

Homing Pigeons

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The Formation of New Orientations during Recrystallization of Silver Single Crystals with {112} Initial Orientation

Materials Science Forum ◽

10.4028/www.scientific.net/msf.467-470.177 ◽

2004 ◽

Vol 467-470 ◽

pp. 177-182 ◽

Cited By ~ 1

Author(s):

Henryk Paul ◽

Julian H. Driver ◽

Claire Maurice ◽

Andrzej Piątkowski

Keyword(s):

Single Crystals ◽

High Purity ◽

Decisive Role ◽

Simple Relation ◽

Initial Orientation ◽

Local Orientation ◽

Isolated Nuclei ◽

Cube Orientation ◽

Early Stages

The recrystallization mechanisms in high purity Ag crystals with C{112}<111> initial orientation, deformed by channel-die compression, have been studied by local orientation measurements using TEM and SEM/EBSD. The microtexture analysis clearly indicates the importance of a simple relation of 25-40o (<111> or <112>) type, which is frequently observed during the early stages of recrystallization between isolated nuclei of uniform orientation and one of the as-deformed groups of components. As recrystallization proceeds, recrystallization twinning increases radically. In C-oriented silver single crystals this latter mechanism also plays a decisive role in the formation of the cube orientation.

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One-way coupling of fiber suspensions through a rotating curved expansion duct

Thermal Science ◽

10.2298/tsci1205405z ◽

2012 ◽

Vol 16 (5) ◽

pp. 1405-1409

Author(s):

Qi-Hua Zhang ◽

Fei Tian ◽

Wei-Dong Shi ◽

Hua Zhang ◽

Xiong-Fa Gao

Keyword(s):

Numerical Method ◽

Flow Structure ◽

Fiber Orientation ◽

Pressure Rise ◽

Initial Orientation ◽

Fiber Suspensions ◽

Inlet Velocity ◽

The One

A numerical method based on the one-way coupling using the Jeffery equation is presented. The influence of the inlet velocity and the initial orientation on the evolution of fiber orientation is investigated. It is observed that the rotation mainly contributes to the pressure rise, and the flow structure is not obviously altered. Due to the one-way coupling, the effects of the inlet velocity and the rotating rate are insignificant.

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Homing trajectories and initial orientation in a Neotropical territorial frog, Allobates femoralis (Dendrobatidae)

Frontiers in Zoology ◽

10.1186/1742-9994-11-29 ◽

2014 ◽

Vol 11 (1) ◽

pp. 29 ◽

Cited By ~ 21

Author(s):

Andrius Pašukonis ◽

Matthias-Claudio Loretto ◽

Lukas Landler ◽

Max Ringler ◽

Walter Hödl

Keyword(s):

Initial Orientation ◽

Allobates Femoralis

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Homing behaviour of pigeons subjected to unilateral zinc sulphate treatment of their olfactory mucosa

Journal of Experimental Biology ◽

10.1242/jeb.199.11.2531 ◽

1996 ◽

Vol 199 (11) ◽

pp. 2531-2535 ◽

Cited By ~ 4

Author(s):

S Benvenuti ◽

A Gagliardo

Keyword(s):

Brain Damage ◽

Zinc Sulphate ◽

Experimental Treatment ◽

Olfactory Mucosa ◽

Initial Orientation ◽

Sulphate Solution ◽

Control Groups ◽

Homing Behaviour ◽

Homing Performance ◽

Zinc Sulphate Solution

Pigeons were made anosmic by unilateral treatment of their olfactory mucosa with a zinc sulphate solution and by plugging the contralateral nostril. In a series of releases at unfamiliar sites, 5579 km from the home loft, the experimental birds' homing behaviour was compared with that of two control groups: unmanipulated control birds, and birds subjected to unilateral zinc sulphate treatment and equipped with an ipsilateral nasal plug. The experimental pigeons exhibited homing behaviour  in terms of both homeward initial orientation and homing performance  significantly poorer than that of both unmanipulated and treated control pigeons. In addition, the homing behaviour of the treated controls turned out to be only slightly, and not significantly, poorer than that of the unmanipulated birds. The results show that the impaired homing capabilities of the zinc-sulphate-treated birds are due to the lack of navigational information and not to non-specific brain damage caused by the experimental treatment.

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Stable equilibrium configurations of an oblate capsule in simple shear flow

Journal of Fluid Mechanics ◽

10.1017/jfm.2015.759 ◽

2016 ◽

Vol 791 ◽

pp. 738-757 ◽

Cited By ~ 13

Author(s):

C. Dupont ◽

F. Delahaye ◽

D. Barthès-Biesel ◽

A.-V. Salsac

Keyword(s):

Aspect Ratio ◽

Shear Flow ◽

Simple Shear ◽

Capillary Number ◽

Stable Equilibrium ◽

Viscosity Ratio ◽

Shear Plane ◽

Initial Orientation ◽

Simple Shear Flow ◽

Mechanical Equilibrium

The objective of the paper is to determine the stable mechanical equilibrium states of an oblate capsule subjected to a simple shear flow, by positioning its revolution axis initially off the shear plane. We consider an oblate capsule with a strain-hardening membrane and investigate the influence of the initial orientation, capsule aspect ratio$a/b$, viscosity ratio${\it\lambda}$between the internal and external fluids and the capillary number$Ca$which compares the viscous to the elastic forces. A numerical model coupling the finite element and boundary integral methods is used to solve the three-dimensional fluid–structure interaction problem. For any initial orientation, the capsule converges towards the same mechanical equilibrium state, which is only a function of the capillary number and viscosity ratio. For$a/b=0.5$, only four regimes are stable when${\it\lambda}=1$: tumbling and swinging in the low and medium$Ca$range ($Ca\lesssim 1$), regimes for which the capsule revolution axis is contained within the shear plane; then wobbling during which the capsule experiences precession around the vorticity axis; and finally rolling along the vorticity axis at high capillary numbers. When${\it\lambda}$is increased, the tumbling-to-swinging transition occurs for higher$Ca$; the wobbling regime takes place at lower$Ca$values and within a narrower$Ca$range. For${\it\lambda}\gtrsim 3$, the swinging regime completely disappears, which indicates that the stable equilibrium states are mainly the tumbling and rolling regimes at higher viscosity ratios. We finally show that the$Ca$–${\it\lambda}$phase diagram is qualitatively similar for higher aspect ratio. Only the$Ca$-range over which wobbling is stable increases with$a/b$, restricting the stability ranges of in- and out-of-plane motions, although this phenomenon is mainly visible for viscosity ratios larger than 1.

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