Radial invariant of 2D and 3D Racah moments

In this paper, we introduce new sets of 2D and 3D rotation, scaling and translation invariants based on orthogonal radial Racah moments. We also provide theoretical mathematics to derive them. Thus, this work proposes in the first case a new 2D radial Racah moments based on polar representation of an object by one-dimensional orthogonal discrete Racah polynomials on non-uniform lattice, and a circular function. In the second case, we present new 3D radial Racah moments using a spherical representation of volumetric image by one-dimensional orthogonal discrete Racah polynomials and a spherical function. Further 2D and 3D invariants are extracted from the proposed 2D and 3D radial Racah moments respectively will appear in the third case. To validate the proposed approach, we have resolved three problems. The 2D/ 3D image reconstruction, the invariance of 2D/3D rotation, scaling and translation, and the pattern recognition. The result of experiments show that the Racah moments have done better than the Krawtchouk moments, with and without noise. Simultaneously, the mentioned reconstruction converges rapidly to the original image using 2D and 3D radial Racah moments, and the test 2D/3D images are clearly recognized from a set of images that are available in COIL-20 database for 2D image, and PSB database for 3D image.     

Characterization of the harmful effect of olive mill wastewater on spearmint

In this study, changes in viability, biomass production, essential oil yield and essential oil composition of Mentha spicata L. (spearmint) exposed to olive mill wastewater (OMW) were investigated. Spearmint cuttings were sensitive to OMW and, after 6 h of incubation in raw or diluted OMW, their viability was null. The short contact of raw OMW with mint cuttings caused an irreversible damage in rhizogenesis and shoots development. Roots were more sensitive to phytotoxicity than shoots. In a field essay, spearmint showed a good capability to recover when OMW was spread at 8 l m⁻² at the vegetative phase of growth (45 days after plantation). At this dose, a slight increase of mostly of the mint essential oil constituents was obtained. When the dose applied was 16 l m⁻², phytotoxicity was manifested by a high reduction of biomass and essential oil yield. The essential oil composition was also affected and a disappearance of many of mint essential oil constituents was observed with an increase of 59% for carvone, the major compound of spearmint essential oil. As far as we know, this is the first report on the effect of field application of OMW on an aromatic plant essential oil yield and composition.     

Laser‐Assisted Strain Engineering of Thin Elastomer Films to Form Variable Wavy Substrates for Cell Culture

Endothelial and epithelial cells usually grow on a curved environment, at the surface of organs, which many techniques have tried to reproduce. Here a simple method is proposed to control curvature of the substrate. Prestrained thin elastomer films are treated by infrared laser irradiation in order to rigidify the surface of the film. Wrinkled morphologies are produced upon stress relaxation for irradiation doses above a critical value. Wrinkle wavelength and depth are controlled by the prestrain, the laser power, and the speed at which the laser scans the film surface. Stretching of elastomer substrates with a “sand clock”‐width profile enables the generation of a stress gradient, which results in patterns of wrinkles with a depth gradient. Thus, different combinations of topography changes on the same substrate can be generated. The wavelength and the depth of the wrinkles, which have the characteristic values within a range of several tens of µm, can be dynamically regulated by the substrate reversible stretching. It is shown that these anisotropic features are efficient substrates to control polarization of cell shapes and orientation of their migration. With this approach a flexible tool is provided for a wide range of applications in cell biophysics studies.     

Mechanically Switchable Biocide Plasma‐Polymer Coatings for Biomaterials

Silver nanoparticles are enclosed between two plasma‐polymer layers. We show that the second cross‐linked plasma‐polymer network acts as a barrier and significantly reduces the delivery of the silver nanoparticles into a surrounding aqueous environment. When the film is stretched, cracks appear in the plasma‐polymer layer, which allow an increase in the release of the silver. When the system returns to its initial length, the release is reduced because of the cracks' closure. The principle is described and the release of silver is evaluated under mechanical stimuli cycles. The antibacterial effect is stopped by the barrier of the plasma‐polymer layer but restored by stretching the coated material.     

Effect of plasma duty cycle on silver nanoparticles loading of cotton fabrics for durable antibacterial properties

A facile method for strongly anchoring silver nanoparticles (AgNPs) onto cotton fabrics was reported. It consists in loading AgNPs onto the cotton fiber preliminary coated with maleic anhydride plasma polymer layer. This results in hydrolyzis and ring opening of anhydride groups followed by electrovalent bonding of silver ions and reduction in NaBH₄. X‐ray photoelectron spectroscopy (XPS), infrared spectroscopy, and scanning electron microscope (SEM) were used to analyze changes in the surface chemical composition and morphology of the plasma modified fibers. The presence of AgNPs was confirmed by UV–Visible spectroscopy and atomic force microscopy (AFM) images. Remarkably, varying plasma duty cycle for plasma polymer deposition allowed tailoring the amount of loaded AgNPs. The highest amount of AgNPs was obtained with the lowest duty cycle values. Qualitative tests showed that silver containing plasma modified cotton displays significant antibacterial activity. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41279.     

Influence of plasma duty cycle during plasma polymerization in adhesive bonding

Junctions between aluminium substrates and ethylene-co-propylene-co-diene terpolymer (EPDM) have been strengthened by depositing alkene functionalized plasma polymers on the aluminium side. The double bonds in the plasma polymer layer were able to covalently bond to the EPDM during the crosslinking step with peroxide. Variations in the peel strength were observed by varying of the plasma duty cycle during plasma polymer deposition. The higher peel strength was obtained with low duty cycles. Analysis of the failure after peel tests showed a cohesive rupture in the EPDM substrate. The differences were explained by analysing the respective concentration of alkene groups in the plasma polymer layer.     

Robust classification of 3D objects using discrete orthogonal moments and deep neural networks

Multimedia Tools and Applications - In this paper, we propose a new model based on 3D discrete orthogonal moments and deep neural networks (DNN) to improve the classification accuracy of 3D objects...     

First-Principles Calculations of Defect Structures in B2 AlCo and GaCo

First-principles electronic structure calculations have been performed for defect structures in nonstoichiometric B2 AlCo and GaCo. To determine the type of constitutional defects, the compositional dependence of the energy of formation and lattice parameter was obtained by calculations employing supercells of various sizes (16 and 32 atoms) as well as special quasirandom structures (SQSs) developed for random pseudobinary A_1?x B _x C with compositions x = 0.25 and 0.5. According to the results, Co vacancies are the constitutional point defects in the Al-rich side of both B2 AlCo and B2 GaCo, while Co vacancies present the minimum energy for the Ga-rich side. For the Co-rich side of both B2 AlCo and B2 GaCo, the Co antisite is the most stable defect. To investigate the thermal defect concentrations at finite temperature, we adopted the Wagner–Schottky model using enthalpies of formation of point defects obtained from the SQS approach. The present results suggest that the predominant thermal defects in AlCo are of complex type whereas for GaCo they are of interbranche Co type. The results of these calculations show agreement with available theoretical and experimental data.     

Efficient color face recognition based on quaternion discrete orthogonal moments neural networks

Multimedia Tools and Applications - In recent years, with the rapid development of multimedia technologies, color face recognition has attracted more attention in various areas related to the...