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51.
Yassine Koubaa 《Mathematical and Computer Modelling of Dynamical Systems: Methods, Tools and Applications in Engineering and Related Sciences》2013,19(4):363-375
This paper deals with a new approach to the parameters estimation of three-phase induction motors with least-squares techniques. The identification method is based on the steady-state electrical equations of induction motor and allows the use of linear identification algorithms. Measurements of the stator currents and voltages and rotor angular speed are required for the identification procedure based on a simple algorithm. The main feature of the proposed procedure is the possibility of estimating the rotor resistance, self-inductance of the rotor winding and the stator leakage inductance parameters without measuring the rotor flux magnitude. The estimated parameters are compared with similar available data obtained with a 3 kW induction motor to evaluate the consistence and performance of the proposed method. 相似文献
52.
Fadoua Asraoui Ayoub Kounnoun Francesco Cacciola Fouad El Mansouri Imad Kabach Yassine Oulad El Majdoub Filippo Alibrando Katia Arena Emanuela Trovato Luigi Mondello Adnane Louajri 《Molecules (Basel, Switzerland)》2021,26(11)
Medicinal plants offer imperative sources of innovative chemical substances with important potential therapeutic effects. Among them, the members of the genus Inula have been widely used in traditional medicine for the treatment of several diseases. The present study investigated the antioxidant (DPPH, ABTS and FRAP assays) and the in vitro anti-hyperglycemic potential of aerial parts of Inula viscosa (L.) Aiton (I. viscosa) extracts through the inhibition of digestive enzymes (α-amylase and α-glucosidase), responsible of the digestion of poly and oligosaccharides. The polyphenolic profile of the Inula viscosa (L.) Aiton EtOAc extract was also investigated using HPLC-DAD/ESI-MS analysis, whereas the volatile composition was elucidated by GC-MS. The chemical analysis resulted in the detection of twenty-one polyphenolic compounds, whereas the volatile profile highlighted the occurrence of forty-eight different compounds. Inula viscosa (L.) Aiton presented values as high as 87.2 ± 0.50 mg GAE/g and 78.6 ± 0.55mg CE/g, for gallic acid and catechin, respectively. The EtOAc extract exhibited the higher antioxidant activity compared to methanol and chloroform extracts in different tests with (IC50 = 0.6 ± 0.03 µg/mL; IC50 = 8.6 ± 0.08 µg/mL; 634.8 mg ± 1.45 AAE/g extract) in DPPH, ABTS and FRAP tests. Moreover, Inula viscosa (L.) Aiton leaves did show an important inhibitory effect against α-amylase and α-glucosidase. On the basis of the results achieved, such a species represents a promising traditional medicine, thanks to its remarkable content of functional bioactive compounds, thus opening new prospects for research and innovative phytopharmaceuticals developments. 相似文献
53.
Malouche Abdelmalek Oumellal Yassine Ghimbeu Camelia Matei de Yuso Alicia Martínez Zlotea Claudia 《Journal of nanoparticle research》2017,19(8):1-11
Journal of Nanoparticle Research - Copper/silver core/shell nanopowders with different metal ratio have been elaborated by electrochemistry (ultrasound-assisted electrolysis followed by a... 相似文献
54.
Driss Kiouach;Salim El Azami El-idrissi;Yassine Sabbar; 《Mathematical Methods in the Applied Sciences》2024,47(1):297-317
Compartmental systems like the well-famed SIR, SEIR, SQIR, SVIR, and their variants are efficient tools for the mathematical modeling of infectious illnesses, and they permit us to get a clear picture of how they proliferate. In actuality, the aleatory fluctuations factors present in the natural environment like storm surges, weather changes, and seismic tremors make the dissemination of epidemics susceptible to some randomness. This calls for a stronger mathematical formulation that takes into consideration this stochasticity effect. From this perspective, and in order to highlight in the same time the effect of the vaccination strategy, we survey in this paper an SVIR model with general incidence rates that is disturbed by both Brownian motions and Lévy jumps. Initially, we establish its well-posedness in the sense that it has a unique positive and global-in-time solution. Then, we rely on some assumptions and nonstandard analytic techniques, to derive sufficient and almost necessary conditions for extinction, persistence in the mean, and also weak persistence. More explicitly, we identify firstly under some hypotheses a threshold λ$$ lambda $$ between extinction and persistence in the mean. In other phrases, if λ<0$$ lambda <0 $$, the infected population dies out while it persists in the mean when λ>0$$ lambda >0 $$. Then, and by modifying the hypothetical framework in order to cover more incidence rates, we prove that λ$$ lambda $$ can act also as a threshold between extinction and weak persistence. At last, we provide some numerical simulations to corroborate our findings and cover some particular cases of response functions. 相似文献
55.
This research aims to highlight and examine an example of ecological complexity. By taking into account the interference between predator and prey, we introduce an ecological system with a general functional response. This model is perturbed by a novel class of fluctuations in the polynomial form. Analytically, we present an alternative method to obtain the acute threshold between stationarity and predator disappearance. Our analysis enriches and improves the work of Zhou et al. (2021) by unifying the criteria of said asymptotic characteristics. Numerically, we audit the accuracy of our threshold in three particular situations: linear, quadratic and cubic perturbations. We establish that the increasing order of disturbance has a passive influence on the extinction time of predators. This finding highlights that complex noise sources have a positive role in the transient dynamics of ecological systems. 相似文献
56.
Nadia Naim Aziz Bouymajane Yassine Oulad El Majdoub Said Ezrari Rachid Lahlali Abdessalem Tahiri Said Ennahli Roberto Lagan Vinci Francesco Cacciola Luigi Mondello Ilham Madani 《Molecules (Basel, Switzerland)》2023,28(1)
Saffron petals, which are the main by-products of Crocus sativus L. (Iridaceae family), are produced in large quantities and are known for their many beneficial properties. In this regard, this study aims to investigate the phenolic composition and antibacterial properties of hydroethanolic extracts from Crocus sativus L. petals collected from Serghina (province of Boulmane) in Morocco. The phenolic profiles were characterized using high-performance liquid chromatography coupled to a photodiode array and electrospray ionization mass spectrometry (HPLC-PDA-ESI/MS). The antibacterial potential was evaluated against four bacterial strains potentially causing food-borne disease (Staphylococcus aureus, Salmonella typhimurium, Escherichia coli, and Listeria monocytogenes) using disc diffusion and broth micro-dilution assays. Results showed that a total of 27 phenolic compounds was detected in the Crocus sativus L. petal extracts, which were assigned to flavonoids (kaempferol, quercetin, isorhamnetin, and myricetin derivatives). The most abundant compound was represented by kaempferol-sophoroside isomer (20.82 mg/g ± 0.152), followed by kaempferol-sophoroside-hexoside (2.63 mg/g ± 0.001). The hydroethanolic extracts of Crocus sativus L. petals demonstrated bactericidal effects against Staphylococcus aureus and Listeria monocetogenes and bacteriostatic effects against Escherichia coli and Salmonella typhimurium. Therefore, the by-product Crocus sativus L. petal extracts might be considered as valuable sources of natural antibacterial agents with potential applications in the food and pharmaceutical industries. 相似文献
57.
Abdelhak Ferroudj;Yassine Djaballah; 《physica status solidi b》2024,261(9):2400005
Herein, first-principles calculations using the planewave pseudopotential technique to assess the structural, elastic, vibrational, and thermal properties of equiatomic intermetallic consisting of rare earth elements (Eu, Gd, Ho, Y, Tb) and noble metals (Au, Pd) are used. This approach involves optimizing novel orthorhombic structures by minimizing the total energy and interatomic forces. The computed structural features for the investigated intermetallics closely align with available experimental data. By evaluating stability criteria using the derived elastic constants, this analysis verifies the stability of these intermetallics in an orthorhombic structure at zero pressure. Furthermore, various mechanical parameters are determined, including (Young's E, bulk B, shear G, Pugh's) modulus, Poisson's ratio, and anisotropy factors. These parameters are derived from the computed single-crystal elastic constants using the Voigt–Reuss–Hill average method. This investigation delves into the relationship between temperature and variations in heat capacity at constant volume (Cv) and entropy (S), comprehensively exploring these variables. 相似文献
58.
Aouali Kerbouche Moued Mebrek Mustapha Zemouli Mohamed Berber Zeggai Souar Yassine Benallou Mohammed Elkeurti 《Crystal Research and Technology》2023,58(11):2300134
In this work, the structural, electronic, elastic, optical, and magnetic properties for the B1, B2, and B3 phases of Sr0.875Mn0.125O with relaxed structure (RS) and unrelaxed structure (URS) are investigated. The investigations are accomplished by the adoption of first-principle methods established on spin-polarized density functional theory, based on the full-potential linearized augmented plane wave method as implemented in the WIEN2k code, where the electronic exchange-correlation potential is studied by the Perdew–Burke–Ernzerhof generalized gradient approximation (GGA-PBEsol) and the revised TB-mBJ rapprochement. The negative formation energy and elastic constant that are acquired indicate the thermodynamical and mechanical stability of all these structures. The ternary Sr0.875Mn0.125O alloys for all structures show half-metallic ferromagnetic behavior with a spin polarization of 100 % at the Fermi level, except the B2 phase without unrelaxed structure (URS). The total magnetic moments are 5 µB for all compounds and the interaction is ferromagnetic between Mn─Sr and Mn─O sites. Optical properties such as refractive index and the optical reflectivity for these alloys are computed and discussed. These materials are half-metallic ferromagnets, and they can be desirable applicants for spintronics implementations and ultraviolet spectra. 相似文献
59.
Rahib Yassine Sarh Brahim Chaoufi Jamal Bonnamy Sylvie Elorf Abdallah 《Journal of Thermal Analysis and Calorimetry》2021,145(5):2405-2416
Journal of Thermal Analysis and Calorimetry - A detailed investigation of the physicochemical properties and thermal characteristics of argan fruit residues (AFRs) was carried out to identify their... 相似文献
60.
We derive the general solution of the semi-relativistic spinless Salpeter equation in the presence of a time-dependent linear potential via the Lewis–Riesenfeld framework and using two forms of the invariant. For comparison, we reobtain the solution in the momentum-space directly by applying a time-momentum transformation to the involved partial differential equation. We also investigate the classical-quantum correspondence for the model in the case of time-periodic force using a momentum-space Gaussian wave-packet. 相似文献