22 documents found, page 1 of 3
The Portuguese Large Wildfire Spread database (PT-FireSprd)
Benali, A.; Guiomar, N.; Gonçalves, H.; Mota, B.; Silva, F.; Fernandes, P.M.; Mota, C.; Penha, A.; Santos, J.; Pereira, J.M.C.; Sá, A.C.L.Wildfire behaviour depends on complex interactions between fuels, topography, and weather over a wide range of scales, being important for fire research and management applications. To allow for significant progress towards better fire management, the operational and research communities require detailed open data on observed wildfire behaviour. Here, we present the Portuguese Large Wildfire Spread database (PT...
Study of physical properties of the Li0.5MgFe1.5O3.5 ferrite nanoparticles
Jeidd, Abddaim; Amghar, Mohamed; Mabrouki, A; Benali, A.; Trabelsi, A; Dhahri, E; Khirouni, K; Costa, B. F. O.In the present research study, the structural, optical, magnetic, electrical and dielectrical properties of the spinel ferrite Li0.5MgFe1.5O3.5, synthesized using a sol-gel auto-combustion method were studied. X-ray diffraction, Fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy revealed that this sample crystallizes in a cubic spinel structure with space group Fd3̄m. Moreover, the optical i...
Wildfires in Europe: Burned soils require attention
Vieira, D.C.S.; Borrelli, P.; Jahanianfard, D.; Benali, A.; Scarpa, S.Annually, millions of hectares of land are affected by wildfires worldwide, disrupting ecosystems functioning by affecting on-site vegetation, soil, and above- and belowground biodiversity, but also triggering erosive off-site impacts such as water-bodies contamination or mudflows. Here, we present a soil erosion assessment following the 2017’s wildfires at the European scale, including an analysis of vegetatio...
A method to produce a flexible and customized fuel models dataset
Sá, A.C.L.; Benali, A.; Aparicio, B.A.; Bruni, C.; Mota, C.; Pereira, J.M.C.; Fernandes, P.M.Simulation of vegetation fires very often resorts to fire-behavior models that need fuel models as input. The lack of fuel models is a common problem for researchers and fire managers because its quality depends on the quality/availability of data. In this study we present a method that combines expert- and research-based knowledge with several sources of data (e.g. satellite and fieldwork) to produce customize...
Investigation of temperature and frequency dependence of the dielectric propert...
Bougoffa, Amira; Benali, E. M.; Benali, A.; Bejar, M.; Dhahri, E.; Graça, M. P. F.; Valente, M. A.; Otero-Irurueta, G.; Costa, B. F. O.In this work we synthesized the multifunctional (La0.8Ca0.2)0.4Bi0.6FeO3 material using a sol-gel process. Structural and morphologic investigations reveal a Pnma perovskite structure at room temperature with spherical and polygonal nanoparticles. A detailed study of the temperature dependence of the dielectric and electrical properties of the studied material proves a typical FE-PE transition with a colossal v...
Synthesis and study of the structural and dielectric properties of La0.67Ca0.2B...
Dhahri, A.; Zaouali, A.; Benali, A.; Abdelmoulla, N.; Massoudi, J.; Nouri, K.; Bessais, L.; Graça, M. P. F.; Valente, M. A.; Costa, B. F. O.The La0.67Ca0.2Ba0.13Fe1-xMnxO3 perovskite compounds with different manganese concentrations (x = 0.0, 0.03, 0.06) were synthesized by the autocombustion method and annealed at 700 C. The X-ray diffraction (XRD) data indicated that all obtained compounds crystallize in the cubic structure with the Pm3m space group. The increase in the substitution rate has been found to lead to the decrease in the crystallite s...
Electrical conductivity and dielectric properties of Sr doped M-type barium hex...
Marouani, Y.; Massoudi, J.; Noumi, M.; Benali, A.; Dhahri, E.; Sanguino, P.; Graça, M. P. F.; Valente, M. A.; Costa, B. F. O.The Raman results showed that the intensity of the resonance band remains unchanged in Ba1 xSrxFe12O19 compared to the undoped compound (x ¼ 0) indicating that the polarizability did not change during the vibrations. The particle sizes, observed by TEM, are reduced from 228 nm to 176 nm with doping. Electrical conductance measurements show that all samples present semiconductor-like behaviors. The Maxwell–Wagne...
Structural, morphological, Raman, dielectric and electrical properties of La1-2...
Benali, E. M.; Benali, A.; Bejar, M.; Dhahri, E.; Graca, M. P. F.; Valente, M. A.; Costa, B. F. O.La1-2x Ba x Bi x FeO3 (0.00 ≤ x ≤ 0.20) nanoparticles were prepared by the auto-combustion method using glycine as a combustion fuel. X-ray diffractometry (XRD) measurements confirmed the orthorhombic structure of the synthesized compounds with the Pnma space group as a principal majority phase and showed the presence of a very minor secondary phase when x > 0.1. The nanosize criterion of the prepared compounds...
Study of the influence of 2.5% Mg2+ insertion in the B-site of La0.8Ca0.1Pb0.1F...
Issaoui, H.; Benali, A.; Issaoui, F.; Dhahri, E.; Costa, B. F. O.; Graca, M. P. F.; Valente, M. A.; Bouazizi, Mohamed LamjedThis work involves the synthesis and study of physical properties of the La0.8Ca0.1Pb0.1Fe0.975Mg0.025O3 compound, which has been characterized by various experimental techniques, such as X-ray diffraction, SEM and complex impedance spectroscopy. The structural study showed that the La0.8Ca0.1Pb0.1Fe0.975Mg0.025O3 compound crystallized in the orthorhombic structure with the Pnma space group. The particle size a...
Landau mean-field analysis and estimation of the spontaneous magnetization from...
Henchiri, C.; Mnasri, T.; Benali, A.; Dhahri, E.; Valente, M.A.We investigated the critical exponents for the compounds La1-x□xMnO3 (x = 0.1; 0.2 and 0.3) prepared by the sol–gel method. Our samples show a second- order transition inferred from the positive slope, in accordance with the Banerjee Criterion. Using the slope of different models on the TC, the relative slope (RS) was traced. From this perspective, the best models for the three samples prove to be the mean fiel...