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Microstructure and Mechanical Behavior in Dissimilar SAF 2205/API X52 Welded Pipes

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Acta Metallurgica Sinica(English Letters) 2016年第7期29卷 674-682页

作者： Brahim Belkessa Djamel Miroud Naima ouali Billel Cheniti Research Center in Industrial Technologies CRTIP.O. Box 64 16014 Cheraga Algiers Algeria Laboratory of Sciences and Materials Engineering LSGMFGMGP University of Sciences and Technology Houari Boumediene BP 32 E1 Alia Bah Ezzouar 16111 AlgiersAlgeria

The welding of a duplex stainless steel SAF 2205 DSS （UNS 31803） and high strength low alloy steel API X52 by shielded metal arc welding process was conducted using two different filler metals, the duplex E2209 and austenitic E309 grade. The microstructures of the dissimilar metal joints have been investigated by optical microscopy, scanning electron microscopy, energy-dispersive spectroscopy （EDS） and X-ray diffraction. EDS analysis at the interface X52 weld metal showed an evident gradient variation of Cr and Ni between boundaries of fusion and type II, where the highest hardness value was recorded. Tensile strength and toughness values of the weld metal produced by E309 electrode are slightly higher than those of the weld metal produced by E2209 electrode. Potentiodynamic polarization tests of different regions of the welded joints evaluated in 3.5% NaC1 solution exhibit a high corrosion resistance of both weld metals.

关键词： Dissimilar metals welding 2205 duplex stainless steel API X52 HSLA steel Heat-affectedzone Mechanical properties

Interpolation in the Automorphism Group of a Polynomial Ring

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Algebra Colloquium 2020年第3期27卷 587-598页

作者： M'hammed El Kahoui Najoua Essamaoui Mustapha ouali Department of Mathematics Faculty of Sciences Semlalia Cadi Ayyad UniversityP.O.Box 2390MarrakeshMorocco

Let R be a commutative ring with unity and SA_(n)(R)be the group of volumepreserving automorphisms of the polynomial R-algebra R^([n]).Given a proper ideal a of R,we address in this paper the question of whether the canonical group homomorphism SA_(n)(R)→SA_(n)(R/α)is *** an application,we retrieve and generalize,in a unified way,several known results on residual coordinates in polynomial rings.

关键词： polynomial automorphism coordinate residual coordinate

Higgs inflation model with non-minimal coupling in hybrid Palatini approach

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Chinese Physics C 2024年第4期48卷 193-201页

作者： Brahim Asfour Aatifa Bargach Ahmed Errahmani Taoufik ouali Laboratory of Physics of Matter and Radiation University of Mohammed firstBP 717OujdaMorocco

In this paper,we propose a hybrid metric Palatini approach in which the Palatini scalar curvature is non minimally coupled to the scalar *** derive Einstein’s field equations,i.e.,the equations of motion of the scalar ***,the background and perturbative parameters are obtained by means of Friedmann equations in the slow roll *** analysis of cosmological perturbations allowed us to obtain the main inflationary parameters,e.g.,the scalar spectral index and tensor to scalar ratio *** this perspective,as an application of our analysis,we consider the Higgs field with quartic potential,which plays the inflaton role,and show that predictions of Higgs hybrid inflation are in good agreement with recent observational data[***.641,61(2020)].

关键词： non-minimal coupling hybrid metric Palatini Higgs inflation

Polytropic gas cosmology and late-time acceleration

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Chinese Physics C 2024年第11期48卷 220-230页

作者： Safae Dahmani Himanshu Chaudhary Amine Bouali Shibesh Kumar Jas Pacif Taoufik ouali Laboratory of Physics of Matter and Radiation Mohammed I UniversityBP 717OujdaMorocco Department of Applied Mathematics Delhi Technological UniversityDelhi 110042India Pacif Institute of Cosmology and Selfology(PICS) SagaraSambalpur 768224OdishaIndia Department of Mathematics Shyamlal CollegeUniversity of DelhiDelhi-110032India Higher School of Education and Training Mohammed I UniversityBP 717OujdaMorocco

The accelerated expansion of the Universe has sparked significant interest in the mysterious concept of dark energy within *** theories have been proposed to explain dark energy,and many models have been developed to understand its origins and *** research explores cosmic expansion using the Polytropic Gas(PG)approach,which combines Dark Matter(DM)and Dark Energy(DE)into a single mysterious *** used the principles of general relativity and built our model within the homogeneous and isotropic framework of Friedmann-Lemaître-Robertson-Walker(FLRW)*** revised the Original Polytropic Gas(OPG)model to expand its applicability beyond the OPG,to theΛCDM *** model's parameters were carefully adjusted to reflect key cosmological features of the variable PG *** validate our model,we performed a Markov chain Monte Carlo analysis using recent Supernova data from the Pantheon+survey,36 observational data points,162 Gamma-Ray Bursts,and 24 binned Quasars distance modulus *** AIC and BIC criteria indicate that our model is slightly preferred over theΛCDM model based on observational *** also tested our model with data,Supernova,Gamma-Ray Bursts,and Quasars and found that it exhibits a transition from a quintessential to phantom *** Polytropic dark fluid model(PDFM)is a promising candidate that effectively addresses the interplay between cosmic acceleration and dark energy.

关键词： polytropic dark energy parametrization

Robust Sliding Mode Control Using Adaptive Switching Gain for Induction Motors

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International Journal of Automation and computing 2013年第4期10卷 303-311页

作者： K. Jamoussi L. Chrifi-Alaoui H. Benderradji A. El Hajjaji M. ouali Laboratory Computer and Embedded Systems National Engineering School University of Sfax Laboratory of Innovative Technology University of Picardie Jules Verne University of M'sila Electrical Engineering Department Laboratory of Modeling Information and Systems University of Picardie Jules Verne France

A robust sliding mode approach combined with a field oriented control （FOC） for induction motor （IM） speed control is presented. The proposed sliding mode control （SMC） design uses an adaptive switching gain and an integrator. This approach guarantees the same robustness and dynamic performance of traditional SMC algorithms. And at the same time, it attenuates the chattering phenomenon, which is the main drawback in actual implementation of this technique. This approach is insensitive to uncertainties and permits to decrease the requirement for the bound of these uncertainties. The stability and robustness of the closed- loop system are proven analytically using the Lyapunov synthesis approach. The proposed method attenuates the effect of both uncertainties and external disturbances. Experimental results are presented to validate the effectiveness and the good performance of the developed method.

关键词： Sliding mode control field oriented control (FOC) practical validation switching gain induction motor.

Chemical composition and larvicidal activity of essential oil of Origanum majorana(Lamiaceae) cultivated in Morocco against Culex pipiens(Diptera:Culicidae)

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Asian Pacific Journal of Tropical Biomedicine 2014年第9期4卷 746-750页

作者： Fouad El-Akhal Abdelhakim El ouali Lalami Yassine Ez Zoubi Hassane Greche Raja Guemmouh Regional Diagnostic Laboratory Epidemiological and Environmental Hygiene Regional Health DirectorateEL Ghassani HospitalFezMorocco Sidi Mohamed Ben Abdellah University Faculty of Sciences Dhar El MahrazLaboratory Analysis and Modelling of Ecosystems ContinentalsFezMorocco National Institute of Medicinal and Aromatic Plants Sidi Mohamed Ben Ahdellah University.FezMorocco

Objective:To evaluate the larvicidal activity of essential oil of Origanum mtijoruna(Lamiaceae)cultivated in Morocco against Culex pipiens(Diptera:Culicidae).Methods:The analysis and the identification of the various constituents of essential oil were carried out by gas chromatography coupled with mass *** test was performed according to a standard methodology inspired by the World Health Organization protocol with slight ***:This oil mainly consisted of monoterpene and *** majority compounds are 4-terpinene(28.96%),y-terpinene(18.57%),α-terpinene(12.72%) and sabinene(8.02%).The lethal concentrations(LC_(50) and LC_(90)) measured for the essential oil Origanum majorana,were respectively of the order of 258.71 mg/L and 580.49 mg/***:The results could be useful in search for newer,safer,and more effective natural larvicidal agents.

关键词： Essential oil Origanum majorana Culex pipiens Larvicidal activity Morocco Fez

A Comparison of the Performance of Various Estimators of Parametric Type1 Tobit Model

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Open Journal of Statistics 2013年第1期3卷 1-4页

作者： El ouali Rahmani Abdelali Kaaouachi Said El Melhaoui University of Mohammed first (EST) Oujda Morocco University of Mohammed first (FS) Oujda Morocco University of Mohammed first (FSJES) Oujda Morocco

In this paper, we use Monte Carlo simulations to compare parametric estimators of Type 1 Tobit model. In particular, we examine the performance for finite samples of three different estimators of simple Tobit model: the least squares (LS) estimator, the Heckman (H) estimator and the maximum likelihood (ML) estimator. These three estimators are consistent and asymptotically normal in the case where the density error is specified. However, these properties are sensitive to the situation where the error distribution is not specified. The purpose of this article is to determine properties of the three estimators, namely bias and convergence, by using Monte Carlo simulations.

关键词： Type 1 Tobit Model Parametric Estimation Monte Carlo Simulation

Diachronic Study of the Vegetation Covers Spatiotemporal Change Using GIS and Remote Sensing in the Ferkla Oasis: Case Study, Bour El Khourbat, Tinjdad, Morocco

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Journal of Geoscience and Environment Protection 2022年第1期10卷 173-188页

作者： Meryem El Amraoui Lahcen Kabiri Amina Kassou Lamya ouali Alexis Nutz Department of Geosciences Geo-Resource-Geo-Environment-Geological patrimony and Oasis Heritage Research Team Faculty of Sciences and Techniques of Errachidia Moulay Ismail University Boutalamine-Errachidia Morocco European Center for Research and Education in Environmental Geosciences Aix Marseille University Marseille France

The Oasis of Ferkla is part of the Oases of Tafilalt in southern Morocco. These are classified by UNESCO as the Oases of Southern Morocco Biosphere Reserve. The Ferkla Oasis is increasingly experiencing a situation of increased regression and degradation, aggravated by the effects of climate change. These foreshadow a considerable acceleration of desertification and drought with the effect of the loss of production systems whose social, ecological and economic role remains major for the whole country. In order to contribute to a better understanding of the dynamics of the vegetation in this territory and the impact of climate change in the Oasis of Ferkla, we used spatial remote sensing to trace the evolution of changes in the vegetation cover in an agricultural extension called Bour El Khourbat. Calculation of the Normalized Difference Vegetation Index for seven multidate satellite images allowed us to follow the vegetation in this oasis zone from the year 1984 to 2019. Indeed, from these multi-temporal images, this study clearly shows the evolution of the vegetation with a remarkable agricultural extension towards the South-East of the zone. This extension is due not only to the installation of a diversion dam upstream but also to the development of the localized irrigation system “Drop by Drop” which is a technique that saves water resources in addition to the presence in the area. Bour El Khourbat specifies a geological structure, in the primary, relatively favorable to having water linked to cracks.

关键词： Climate Change Remote Sensing GIS Vegetation Change Detection Ferkla Oasis

Morphological Identification of the Main Fungi Associated with Sesame in Burkina Faso

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American Journal of Plant Sciences 2023年第8期14卷 882-895页

作者： Dianyagou Paul ouali Pawindé Elisabeth Zida Wendolian Romain Soalla Kuilpoko Marie Laure Guissou Laboratoire Sciences de la Vie et de la Terre (LASVT) Université Norbert Zongo Koudougou Burkina Faso Laboratoire de Phytopathologie et de Biotechnologie Végétale Institut de l’Environnement et de Recherches Agricoles/CNRST Ouagadougou Burkina Faso

Several fungal species are responsible for diseases that damage sesame crop and cause production losses. These seed-borne fungi cause serious damage by reducing seed germination. To identify the fungi associated with sesame seeds in Burkina Faso, 72 sesame seed samples were collected from 24 localities in the main production areas (Sudanian zone, Sudano-Sahelian zone, Sahelian zone). These samples were submitted for seed health analysis using the blotting paper incubation method. The results obtained revealed that the seed samples were contaminated by various fungi, the main ones being: Fusarium spp. Link: Fr. infecting 97.22% of the samples, Macrophomina phaseolina (Tassi) Goid. (90.28%), Alternaria sesamicola E. Kawamura (83.33%), Curvularia lunata (Wakker) Boedijn (76.39%), Cercospora sesami A. Zimmerm. (73.61%), Phoma sorghina Boerema, Dorenbosch, & Van Kesteren (73.61%), Aspergillus flavus Link: Fr. (69.44%), Cladosporium sphaerospermum Penz. (56.94%), Rhizopus sp. Ehrenb. (40.28%) and A. niger Tiegh. (36.11%). In each seed sample, 0.25% to 94% of the seeds host one or more fungal species. Regarding the climatic zones, the results revealed that A. sesamicola and A. flavus were more represented in the Sudanian zone than in the Sudano-Sahelian and Sahelian zones;while P. sorghina, and C. sphaerospermum were more encountered in the Sahelian zone than in the other two zones. This study showed that the majority of sesame seeds produced and used by farmers in Burkina Faso host one or more species of fungi at high levels.

关键词： Sesame Fungi Associated with Seeds Seed Health Analysis Burkina Faso