Band Moire images

We propose a new powerful way of synthesizing moire images that enables the creation of dynamically moving messages incorporating text, symbols, and color elements. Moire images appear when superposing a base layer made of replicated base bands and a revealing layer made of a line grating comprising thin transparent lines. Each replicated base band contains the same image, e.g. text or color motifs. Since the base bands and the revealing line grating have similar periods, the revealed moire image is the image located within each base band, enlarged along one dimension. By considering the formation of the moire image as a line sampling process, we derive the linear transformation between the base layer and the moire image. We obtain the geometric layout of the resulting moire image, i.e. its orientation, size and displacement direction when moving the revealing layer on top of the base layer. Interesting moire images can be synthesized by applying geometric transformations to both the base and the revealing layers. We propose a mathematical model describing the geometric transformation that a moire image undergoes, when its base layer and its revealing layer are subject to different freely chosen non-linear geometric transformations. By knowing in advance the layout of a moire image as a function of the layouts of the base layer and of the revealing layer, we are able to create moire components running up and down at different speeds and orientations upon translation of the revealing layer. We also derive layer transformations which yield periodic moire images despite the fact that both the base and the revealing layers are curved. By offering a new means of artistic expression, band moire images can be used to create new designs and to synthesize visually appealing applications. © 2004 ACM

Color gamut reduction techniques for printing with custom inks

Printing with custom inks is of interest both for artistic purposes and for printing security documents such as banknotes. However, in order to create designs with only a few custom inks, a general purpose high-quality gamut reduction technique is needed. Most existing gamut mapping techniques map an input gamut such as the gamut of a CRT display into the gamut of an output device such as a CMYK printer. In the present contribution, we are interested in printing with up to three custom inks, which in the general case define a rather narrow color gamut compared with the gamut of standard CMYK printers. The proposed color gamut reduction techniques should work for any combination of custom inks and have a smooth and predictable behavior. When the black ink is available, the lightness levels present in the original image remain nearly identical. Original colors with hues outside the target gamut are projected onto the gray axis. Original colors with hues inside the target gamut hues are rendered as faithful as possible. When the black ink is not available, we map the gray axis G into a colored curve G' connecting in the 3D color space the paper white and the darkest available color formed by the superposition of the 3 inks. The mapped gray axis curve G' is given by the Neugebauer equations when enforcing equal amounts of custom inks. After lightness mapping, hue and saturation mappings are carried out. When the target gamut does not incorporate the gray axis, we divide it into two volumes, one on the desaturated side of the mapped gray axis curve G' and the other on the saturated side of the G' curve. Colors whose hues are not part of the target color gamut are mapped to colors located on the desaturated side of the G' curve. Colors within the set of printable hues remain within the target color gamut and retain as much as possible their original hue and saturatio

Evidence of unidirectional hybridization and second‐generation adult hybrid between the two largest animals on Earth, the fin and blue whales

Biodiversity in the oceans has dramatically declined since the beginning of the industrial era, with accelerated loss of marine biodiversity impairing the ocean's capacity to maintain vital ecosystem services. A few organisms epitomize the damaging and long‐lasting effects of anthropogenic exploitation: some whale species, for instance, were brought to the brink of extinction, with their population sizes reduced to such low levels that may have cause a significant disruption to their reproductive dynamics and facilitated hybridization events. The incidence of hybridization is nevertheless believed to be rare and very little information exist on its directionality. Here, using genetic markers, we show that all but one whale hybrid sample collected in Icelandic waters originated from the successful mating of male fin whale and female blue whale, thus suggesting unidirectional hybridization. We also demonstrate for the first time the existence of a second‐generation adult (male) hybrid resulting from a backcross between a female hybrid and a pure male fin whale. The incidence of hybridization events between fin and blue whales is likely underestimated and the observed unidirectional hybridization (for F1 and F2 hybrids) is likely to induce a reproductive loss in blue whale, which may represent an additional challenge to its recovery in the Atlantic Ocean compared to other rorquals

Color images visible under UV light

The present contribution aims at creating color images printed with fluorescent inks that are only visible under UV light. The considered fluorescent inks absorb light in the UV wavelength range and reemit part of it in the visible wavelength range. In contrast to normal color printing which relies on the spectral absorption of light by the inks, at low concentration fluorescent inks behave additively, i.e. their light emission spectra sum up. We first analyze to which extent different fluorescent inks can be superposed. Due to the quenching effect, at high concentrations of the fluorescent molecules, the fluorescent effect diminishes. With an ink-jet printer capable of printing pixels at reduced dot sizes, we reduce the concentration of the individual fluorescent inks and are able to create from the blue, red and greenish-yellow inks the new colorants white and magenta. In order to avoid quenching effects, we propose a color halftoning method relying on diagonally oriented pre-computed screen dots, which are printed side by side. For gamut mapping and color separation, we create a 3D representation of the fluorescent ink gamut in CIELAB space by predicting halftone fluorescent emission spectra according to the spectral Neugebauer model. Thanks to gamut mapping and juxtaposed halftoning, we create color images, which are invisible under daylight and have, under UV light, a high resemblance with the original images

Effect of a pre-oxide on the high temperature steam oxidation of Zircaloy-4 andM5 alloys

International audienc

Isolation and identification of five free flavonoid aglycones from Thymus numidicus

International audienceFrom the aerial parts of the endemic species Thymus numidicus Poiret locally which is known as "zaatar", belongs to the Lamiaceae family five flavonoids were isolated using chromatographic techniques and identified by spectral analysis (UV-Visible, MS, 1H and 13CNMR) and chromatographic behaviours

Guideline for the introduction of new materials in rcc-mrx code

International audienceThere is a strong diversity of innovative projects. Forinstance, under the GEN IV label, we find six differentconcepts Sodium Fast Reactor, Lead Fast Reactor, Gas FastReactor, Very High Temperature Reactor (Gas), SupercriticalWater Reactor and Molten Salt Reactor.This diversity and the innovative characteristic are inopposition with a codification status, as code and standards arebased on the recognized industrial feedback. By definition, nocode exists for a real innovative system.Existing codes have thus to be adapted or completed tocover the special features of a new concept. Such a process hasbeen engaged for the AFCEN's RCC-MRx Code (Design andConstruction Rules for Mechanical Components in hightemperaturestructures, experimental reactors and fusionreactors) to adapt this code to the GEN IV reactors new needsfor many years now. In this frame, it appears that there is aparticular expectation on how to proceed to introduce a new material in the code