Consider a classical two-dimensional scattering problem: a ray is scattered by a potential composed of several tall, repelling, steep mountains of arbitrary shape. We study when the traditional approximation of this nonlinear far-from-integrable problem by the corresponding simpler billiard problem, of scattering by hard-wall obstacles of similar shape, is justified. For one class of chaotic sc...

Controlling slip is crucial to reliable descent of steep unconsolidated slopes such as those found in lunar craters. The ability to enter these craters provides opportunities to explore potential in-situ resources, such as water ice. We present a rover prototype with a novel, actuated, omni-directional plowing device and control method for maneuvering on steep slopes. Data from field experiment...

We present optical spectroscopy of 62 objects selected from several samples of ultra steep spectrum (USS) radio sources. 46 of these are from our primary catalog, consisting of 669 sources with radio spectral indices α < −1.30 (Sν ∝ ν); this first spectroscopic sub-sample was selected on the basis of their faint optical and near-IR identifications. Most are identified as narrow-lined radio gala...

Experiments on extremely steep deterministic waves generated in a large wave tank by focusing of a broadbanded wave train serve as a motivation for the theoretical analysis of the conditions leading to wave breaking. Particular attention is given to the crest of the steepest wave where both the horizontal velocity and the vertical acceleration attain their maxima. Analysis is carried out up to ...

8 Gradients of PtdIns4P between organelle membranes and the endoplasmic reticulum (ER) 9 are thought to drive counter-transport of other lipids via non-vesicular traffic. This novel 10 pathway requires the SAC1 phosphatase to degrade PtdIns4P in a “cis” configuration at 11 the ER to maintain the gradient. However, SAC1 has also been proposed to act in “trans” 12 at membrane contact sites, which...

Although the Mesoscale Community Compressible (MC2) model successfully reproduces the wind climate (for wind energy development purposes) of the Gaspé region, equivalent simulations for the steep mountainous southern Yukon have been unsatisfactory. An important part of the problem lies in the provision of suitable boundary conditions in the lower troposphere. This paper will describe an alterna...

Abstract Analyzing a recent case of the church’s involvement in geothermal project Wae Sano, Flores, Indonesia, from an ecclesiological point view, this article aims to demonstrate one formidable obstacle realization vision synodal church. While many theological reflections following Pope Francis’s pronouncement notion ‘an entirely Church’ have led conclusion that synodality is modus vivendi et...