Energetic proton acceleration from concave targets, the fronts of which were irradiated with 40 fs laser pulses with an intensity of 10 W/cm, has been studied as a function of the depth of the concave shape. Three kinds of targets, a triangular concave target, a circular concave target and a parabolic concave target are considered. When the depth of the concave shape was varied, the peak proton...

Crowdsourcing marketplace as a new platform for companies or individuals to source ideas or works from the public has become popular in the contemporary world. A key issue about the sustainability of this type of marketplace relies on the effort that problem solvers expend on the online tasks. However, the predictors of effort investment in the crowdsourcing context is rarely investigated. In t...

In this paper we use the method of upper and lower solutions combined with degree theoretic techniques to prove the existence of multiple positive solutions to semipositone superlinear systems of the form −∆u = g1(x, u, v) −∆v = g2(x, u, v) on a smooth, bounded domain Ω ⊂ R with Dirichlet boundary conditions, under suitable conditions on g1 and g2. Our techniques apply generally to subcritical,...

This paper describes the Region Occlusion Calculus (ROC-20), that can be used to model spatial occlusion and the effects of motion parallax of arbitrary shaped objects. ROC-20 assumes the region based ontology of RCC-8 and extends Galton’s Lines of Sight Calculus by allowing concave shaped objects into the modelled domain. This extension is used to describe the effects of mutually occluding bod...

The tricyclic system of the title compound, C(22)H(15)Br, has a concave shape, with a dihedral angle between the benzene ring planes of 48.68 (1)°.

Our aim is to investigate the elevation of matrix proteins in tissues obtained from distal, above the sinotubular junction (proximal), concave, and convex sites of aneurysms in the ascending aorta using a simultaneous multiplex protein detection system. Tissues were collected from 41 patients with ascending aortic aneurysms. A total of 31 patients had a bicuspid aortic valve (BAV), whereas 10 h...

Concave compositions are compositions (i.e. ordered partitions) of a number in which the parts decrease up to the middle summand(s) and increase thereafter. Perhaps the most surprising result is for even length, concave compositions where the generating function turns out to be the quotient of two instances of the pentagonal number theorem with variations of sign. The false theta function disco...