Filler segmentation of SEM paper images based on mathematical morphology

Recent developments in microscopy and image processing have made digital measurements on high-resolution images of fibrous materials possible. This helps to gain a better understanding of the structure and other properties of the material at micro level. In this paper SEM image segmentation based on mathematical morphology is proposed. In fact, paper models images (Whatman, Murillo, Watercolor, Newsprint paper) selected in the context of the Euro Mediterranean PaperTech Project have different distributions of fibers and fillers, caused by the presence of SiAl and CaCO3 particles. It is a microscopy challenge to make filler particles in the sheet distinguishable from the other components of the paper surface. This objectif is reached here by using switable strutural elements and mathematical morphology operators.     

Modeling and optimization of a proton exchange membrane fuel cell using particle swarm algorithm with constriction coefficient

Journal of Thermal Analysis and Calorimetry - The present study aims at estimating the values of an electrochemical model parameter of a proton exchange membrane fuel cell (PEMFC). A variant of the...     

New MIP model for multiprocessor scheduling problem with communication delays

In this paper we consider scheduling tasks on a multiprocessor system, taking into account communication delays. We propose a new Mixed Integer Program (MIP) formulation that drastically reduces both the number of variables and the number of constraints, when compared to the best mathematical programming formulations from the literature. In addition, we propose pre-processing procedures that generates cuts and bounds on all variables, reducing the solution space of the problem as well. Cuts are obtained by using forward and backward critical path method from project management field, while the upper bound is derived from the new greedy heuristic. Computational experience shows advantages of our approach.     

Ethnobotanical study of some aromatic and medicinal plants in the Middle Atlas mountains of Morocco

By the diversity of its soil and climatic factors, Morocco offers a flora particularly rich in aromatic and medicinal plants (MAP). In order to obtain the most information about the flora (flowering times, fruiting, harvesting and their main uses in traditional medicine), a study was conducted in the mountainous Khenifra region. A survey of users of MAP (rural population, herbalists arborists) has been undertaken and was completed by field observations and sampling at different stages of growth. The results showed a range of indigenous and diversified MAP belonging to 10 botanical families (Lamiaceae, Asteraceae, Rosaceae, Chenopodiaceae, Papaveraceae, Caryophyllaceae, Cupressaceae, Rutaceae, Anacardiaceae and Zygophyllaceae). The flowering period of all species, according to the local community surveyed, spread from February (2%) to September (12%), with a significant concentration from April to June (65%).The highest rate of fructification occurred in June-July (64%). The harvesting period of the main MAP from this mountain area stretches mainly from March to April (61%). The mode of propagation stated varied among species, and concerned mainly replication by seeds (53%) and cuttings (24%). Regarding the use of these indigenous MAP as traditional medicines, all plant parts are used, especially leaves, flowers and stems.     

Contribution of weak localization, electron-electron interaction, and Zeeman spin-splitting effects in corrective term “mT” of the metallic conductivity in n-type GaAs

We present measurements of the electrical conductivity of barely metallic n-type GaAs that are driven to the metal-insulator transition (MIT) by magnetic field. The experiments were carried out at low temperature in the range (4.2-0.066 K) and in magnetic field up to 4 T. We have determined the magnetic field for which the conductivity changes from the metallic behavior to insulator regime. On the metallic side of the MIT, the electrical conductivity is found to obey σ=σ₀+mT^1/2 down to 66 mK. Physical explanation to the temperature dependence of the conductivity is given in metallic side of the MIT using a competition between different effects involved in the mechanisms of conduction, like electron-electron interaction effect, Zeeman spin-splitting effect, and weak localization effect.     

Experimental determination of the isothermal (vapour + liquid) equilibria of binary aqueous solutions of sec-butylamine and cyclohexylamine at several temperatures

The vapour pressures of (sec-butylamine + water), (cyclohexylamine + water) binary mixtures, and of pure sec-butylamine and cyclohexylamine components were measured by means of two static devices at temperatures between 293 (or 273) K and 363 K. The data were correlated with the Antoine equation. From these data, excess Gibbs functions (G^E) were calculated for several constant temperatures and fitted to a fourth-order Redlich–Kister equation using the Barker’s method. The (cyclohexylamine + water) system shows positive azeotropic behaviour for all investigated temperatures. The two binary mixtures exhibit positive deviations in G^E for all investigated temperatures over the whole composition range.     

Exponential energy decay of some coupled second order systems

In this paper we characterize the output feedback stabilization of some coupled systems with and without delay. The proof of the main result uses the method introduced in Haraux (Port. Math., 46:245–258, 1989), which consists of reducing the exponential decay of the closed loop system to an observability inequality of its corresponding conservative adjoint system.     

Singular soliton solution and bifurcation analysis of Klein-Gordon equation with power law nonlinearity

In this paper, the Klein-Gordon equation (KGE) with power law nonlinearity will be considered. The bifurcation analysis as well as the ansatz method of integration will be applied to extract soliton and other wave solutions. In particular, the second approach to integration will lead to a singular soliton solution. However, the bifurcation analysis will reveal several other solutions that are of prime importance in relativistic quantum mechanics where this equation appears.     

Impact of the meteorological parameters on the behaviour of 7Be at ground level in Tetouan city,Morocco from June 2015 to February 2017

For the first time, atmospheric aerosols were collected in Tetouan city (Morocco), from June 2015 to February 2017, through which ⁷Be activity was measured. We studied data variation by time series analyses and the impact of local meteorological factors on it. ⁷Be concentrations, in mBq/m³, ranged from 1.65 to 7.79 with mean value of 4.69. ⁷Be behaviour is mainly influenced by air temperature, precipitations, relative humidity and atmospheric pressure. A prediction model was suggested and validated. This study helps understanding climatic variables impact on the environmental processes as aerosols transport and deposit, and to predict ⁷Be behaviour in Mediterranean regions like Tetouan.