51 research outputs found
Valorization of Moroccan olive stones by using it in particleboard panels
The main objective of this work was to find new applications to valorize olive stones (endocarp and seed). In order to improve knowledge on olive stones, the phenolic compounds concentration of three varieties of Moroccan olive trees: Moroccan Picholine, Menara and Haouzian were studied. Olive stones of three varieties were characterized by Fourier Transform Mid Infrared Spectroscopy (FT-MIR). Total phenolic compounds are quantified after solid-liquid extraction by an assay of Folin-Ciocalteu. Moroccan Picholine stones (11.32 mg GAE/g DM) have a higher content of total phenolic compounds than Haouzia stones (4.55 mg GAE/g DM) and Menara stones (3.56 mg GAE/g DM). Thermogravimetric analysis indicates that up to 195 degrees C; there is no degradation of the stones. The biocide performance on agar-agar was tested with decay fungi. Biodegradation studies show that the most interesting results are obtained with Moroccan Picholine stones. The presence of Moroccan Picholine in a particleboard panels improves the total resistance of the particleboard panels against both Coriolus versicolor and Coniophora puteana rot fungi
A multidisciplinary study of chemico-physical properties of different classes of 2-aryl-5(or 6)-nitrobenzimidazoles: NMR, electrochemical behavior, ESR, and DFT calculations
Continuing in our researches on the syntheses, reactivity, pharmacological/biological activities of heterocyclic compounds containing one or more nitrogen atoms we have examined some chemico-physical properties (1H and 13C NMR, electrochemical behavior, and ESR) of three series of 2-aryl-5(or 6)-nitrobenzimidazoles (1–3) variously substituted in the 2-aryl ring. The electrochemical behavior of the nitro group on the benzimidazole ring has been studied by cyclic voltammetry. This has allowed to point out both the reversibility, the formal potential, and the number of electrons involved in the electrochemical processes, and to evaluate the effect of the substituents present on the aryl ring. The data collected have been able to furnish a complete picture of electronic distribution and have been supported by DFT calculations
A new way for the synthesis of pyrazolo-1,5-benzodiazepinethiones from 3,3-dimercapto(or dialkylmercapto)-1-phenyl-2-propen-l-ones
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Biofuels and biochars production from agricultural biomass wastes by thermochemical conversion technologies: Thermogravimetric analysis and pyrolysis studies
Thin-shell wormholes from charged black holes in generalized dilaton-axion gravity
This paper discusses a new type of thin-shell wormhole constructed by
applying the cut-and-paste technique to two copies of a charged black hole in
generalized dilaton-axion gravity, which was inspired by low-energy string
theory. After analyzing various aspects of this thin-shell wormhole, we discuss
its stability to linearized spherically symmetric perturbations.Comment: Minor changes, 6 pages, 4 figures. Accepted for publication in Gen.
Rel. Gra
Two-compartment bipolar membrane electrodialysis for splitting of sodium formate into formic acid and sodium hydroxide: Modelling
Radial stability analysis of the continuous pressure gravastar
Radial stability of the continuous pressure gravastar is studied using the
conventional Chandrasekhar method. The equation of state for the static
gravastar solutions is derived and Einstein equations for small perturbations
around the equilibrium are solved as an eigenvalue problem for radial
pulsations. Within the model there exist a set of parameters leading to a
stable fundamental mode, thus proving radial stability of the continuous
pressure gravastar. It is also shown that the central energy density possesses
an extremum in rho_c(R) curve which represents a splitting point between stable
and unstable gravastar configurations. As such the rho_c(R) curve for the
gravastar mimics the famous M(R) curve for a polytrope. Together with the
former axial stability calculations this work completes the stability problem
of the continuous pressure gravastar.Comment: 17 pages, 5 figures, References corrected, minor changes wrt v1,
matches published versio
Thin-shell wormholes from regular charged black holes
We investigate a new thin-shell wormhole constructed by surgically grafting
two regular charged black holes arising from the action using nonlinear
electrodynamics coupled to general relativity. The stress-energy components
within the shell violate the null and weak energy conditions but obey the
strong energy condition. We study the stability in two ways: (i) taking a
specific equation of state at the throat and (ii) analyzing the stability to
linearized spherically symmetric perturbations about a static equilibrium
solution. Various other aspects of this thin-shell wormhole are also analyzed.Comment: 8 pages and 19 figure
Chebyshev spectral method for studying the viscoelastic slip flow due to a permeable stretching surface embedded in a porous medium with viscous dissipation and non-uniform heat generation
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