In the covalently linked 2D coordination network {[Fe(bbtr)(3)](BF(4))(2)}(∞), bbtr = 1,4-di(1,2,3-triazol-1-yl)butane, the iron(II) centers stay in the high-spin (HS) state down to 10 K. They can, however, be quantitatively converted to the low-spin (LS) state by irradiating into the near-IR spin allowed (5)dd band and back again by irradiating into the visible (1)dd band. The compound shows t...

We present molecular dynamics simulations with empirical potentials to study the type of defects produced when irradiating graphene with low energy carbon ions (100 eV and 200 eV) and different dose rates. Simulations show the formation of very stable structures such as dimers, single chains of carbons and double chains of carbons. These structures are similar to those described in the literatu...

A novel chaotic cryptosystem for hyperspectral image, in this paper, is proposed by using a 4D hyperchaotic system gyrator transform domains. In encryption process, random spiral phase function (RSPF) designed to generate variable mask, which can be used encoding with the image. Subsequently, utilized sequences and these data employed designing RSPF, scrambling image synthesizing complex cipher...

The spiral is one of Nature’s more ubiquitous shape: it can be seen in various media, from galactic geometry to cardiac tissue. In the literature, very specific models are used to explain some of the observed incarnations of these dynamic entities. Barkley [1, 2] first noticed that the range of possible spiral behaviour is caused by the Euclidean symmetry that these models possess. In experimen...

Various PDE models have been suggested in order to explain and predict the dynamics of spiral waves in excitable media. In two landmark papers, Barkley noticed that some of the behaviour could be explained by the inherent Euclidean symmetry of these models. LeBlanc and Wulff then introduced forced Euclidean symmetry-breaking (FESB) to the analysis, in the form of individual translational symmet...

Spiral texture mapping extends and combines two main categories of texture mapping approaches, namely, displacement texture mapping and view-dependent texture mapping. A spiral texture contains two components: a view-independent one and a view-dependent one. The first component contains a layered depth image, which stores the depth information and the extracted diffuse color information of the ...

Spiral Architecture (SA) is a novel image structure which has hexagons but not squares as the basic elements. Apart from many other advantages in image processing, SA has shown two unbeatable characters that have potential to improve image compression performance, namely, Locality of Pixel Density and Uniform Image Partitioning. Fractal image compression is a relatively recent image compression...

Electrical waves circulating around an obstacle in cardiac tissue are subject to a generic oscillatory instability. In a one-dimensional ring geometry this instability can produce both quasiperiodic and spatiotemporally chaotic oscillations while in a two-dimensional sheet of cardiac tissue it can lead to spiral wave breakup. We present a control scheme to prevent this instability in these two ...

Maximizing the sustainable supercurrent density, J C, is crucial to high-current applications of superconductivity. To achieve this, preventing dissipative motion of quantized vortices is key. Irradiation of superconductors with high-energy heavy ions can be used to create nanoscale defects that act as deep pinning potentials for vortices. This approach holds unique promise for high-current app...

The spiral is one of Natures more ubiquitous shape: it can be seen in various media, from galactic geometry to cardiac tissue. Spirals have been studied from a dynamical system perspective starting with Barkley’s seminal papers linking a wide class of spiral wave dynamics to the Euclidean symmetry of the excitable media in which they are observed [1,2]. But physical processes are never perfectl...