muḥyī al-dīn maghribī is among the few astronomers of the middle ages whose astronomical system is entirely based on new measures of planetary parameters and whose measurement of the observational data and calculation processes for determining their amount have been carried out in maragha observatory. he has explained the details of his observations and calculations in a volume called talkhīṣ a...

Binary black hole simulations starting from quasi-circular (i.e., zero radial velocity) initial data have orbits with small but nonzero orbital eccentricities. In this paper, the quasi-equilibrium initial-data method is extended to allow nonzero radial velocities to be specified in binary black hole initial data. New low-eccentricity initial data are obtained by adjusting the orbital frequency ...

Eccentricity-dependent sensitivity losses in spatial discrimination tasks can often be overcome by scaling stimuli at each eccentricity by a factor F=1+E/E(2). However, because there may be more than one eccentricity-dependent limitation at play in a particular task a single scaling function may be insufficient to explain all sensitivity losses as stimuli are moved from foveal to peripheral ret...

Bisection thresholds are approximately proportional to the separation/eccentricity of the targets. This "Weber's law" for position has been invoked over the past century. It is the separation of the reference targets, or their eccentricity which determines the threshold? In previous studies separation and eccentricity are confounded. In the present report we have pitted separation against eccen...

Recently we reported that the topographic organization of visual field eccentricity in human visual cortex extends into high-order, ventral occipitotemporal (VOT) cortex. Within this cortex, regions that respond preferentially to faces and buildings have specific eccentricity biases, suggesting that this category-eccentricity association may reflect differential needs of recognition processes. ...

We calculate the eccentricity excitation of asteroids produced by the sweeping ν6 secular resonance during the epoch of planetesimal-driven giant planet migration in the early history of the solar system. We derive analytical expressions for the magnitude of the eccentricity change and its dependence on the sweep rate and on planetary parameters; the ν6 sweeping leads to either an increase or a...

Inhibition of return (IOR) as an indicator of attentional control is characterized by an eccentricity effect, that is, the more peripheral visual field shows a stronger IOR magnitude relative to the perifoveal visual field. However, it could be argued that this eccentricity effect may not be an attention effect, but due to cortical magnification. To test this possibility, we examined this eccen...

Elastic stability of ring and stringer-stiffened cylindrical shells under axial, internal and external pressures is studied using Ritz method. The stiffeners are rings, stringers and their different arrangements at the inner and outer surfaces of the shell. Critical buckling loads are obtained using Ritz method. It has been found that the cylindrical shells with outside rings are more stable th...

Wheat (Triticum aestivum L.) is known to be the world-leading cereal grain and the most important food in the world of agriculture.  Wheat offers a great wealth of material for genetic studies due to its wide ecological distribution and host of variation for various morphological and physiological characters.  To evaluate the genetic control of physical traits of grain in two crosses of winter ...

The saliency map is a computational model and has been constructed for simulating human saliency processing, e.g. pop-out target detection (e.g. Itti & Koch, 2000). In this study the spatial structure on the saliency map was investigated. It is proposed that the saliency map is structured into processing units whose size is increasing with retinal eccentricity. In two experiments the distance b...