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Plasma Science and Technology 2014年第6期16卷 588-592页

作者： Djilali BENYOUCEF mohammed yousfi Laboratoire Génie Electrique et Energies Renouvelables Chlef University Universitéde Toulouse LAPLACE UMR CNRS

The aim of this paper is to obtain relevant sets of collision cross sections of the parent ions in low pressure discharges in argon, oxygen, and nitrogen, i.e., Ar＋ in Ar, O2＋ in O2 and N2＋ in N2. These ion data are first discussed and then validated from comparisons between the calculated transport coefficients and those measured in the literature. The elastic momentum transfer collision cross sections are determined from a semi-classical approximation for the phase shift calculation based on a 12-6-4 inter-particle potential while ion transport coefficients are determined versus the reduced electric field from Monte Carlo simulations.

关键词： inter-particle interaction potentials phase shift JWKB (Jeffreys WentzelKramers Brillouin) momentum collision cross sections Monte Carlo simulation ion trans-port coefficient

Benchmarks of 3D Laplace Equation Solvers in a Cubic Configuration for Streamer Simulation

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Plasma Science and Technology 2016年第5期18卷 538-543页

作者： Joseph-Marie PLEWA Olivier DUCASSE Philippe DESSANTE Carolyn JACOBS Olivier EICHWALD Nicolas RENON mohammed yousfi Universite de Toulouse UPS INPT LAPLACE (Laboratoire Plasma et Conversion d'Energie) Toulouse Cedex 9 F-31062 France Group of Electrical Engineering-Paris (GeePs) UMR 8507 CNRS CentraleSupelec Universite Paris-Sud-UPMC 11 rue Joliot-Curie Plateau de Moulon 91192 Gif-sur-Yvette Cedex F-91192 France CALMIP Universite de Toulouse-CNRS-INPT-INSA-UPS UMS 3667 France CNRS LAPLACE Toulouse F-31062 France

The aim of this paper is to test a developed SOR R＆B method using the Chebyshev accelerator algorithm to solve the Laplace equation in a cubic 3D configuration. Comparisons are made in terms of precision and computing time with other elliptic equation solvers proposed in the open source LIS library. The first results, obtained by using a single core on a HPC, show that the developed SOR R＆B method is efficient when the spectral radius needed for the Chebyshev acceleration is carefully pre-estimated. Preliminary results obtained with a parallelized code using the MPI library are also discussed when the calculation is distributed over one hundred cores.

关键词： numerical methods for elliptic equations high performance computing 3Dstreamer simulation SOR IDR BiCGSTAB

Electric and Spectroscopic Studies of Pulsed Corona Discharges in Nitrogen at Atmospheric Pressure

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Journal of Analytical Sciences, Methods and Instrumentation 2017年第3期7卷 57-74页

作者： Alyen Abahazem Nofel Merbahi Hasna Guedah mohammed yousfi Departement of Physics LMER Ibn Zohr University Agadir Morocco LAPLACE Université de Toulouse CNRS UPS Toulouse France

This paper is mainly dedicated to the experimental electric and spectroscopic analysis of positive corona discharges in the case of point to plane configuration, generated in nitrogen at atmospheric pressure. The maximum corona current (a few hundreds of mA), the average current (a few μA) and the average propagation velocity (a few 107 cm/s) are analyzed with the variation of the applied voltage (a few kV) and the gap distance (not exceeding 16 mm). By using an ICCD camera, the dynamics of the discharge during the propagation of primary and secondary streamers across the gap distance was analyzed. Spectroscopic study is emphasized in a spectral range from 200 nm up to 500 nm, to determine the important excited species present in the gaseous environment such as the second positive and the first negative systems (SPS and FNS respectively). The identification of the quenching NOγ emission bands is also emphasized.

关键词： Corona Discharge Nitrogen Atmospheric Pressure Spectroscopic Study ICCD Camera

Measurements of Absolute Atomic Nitrogen Density by Two-Photon Absorption Laser-Induced Fluorescence Spectroscopy in Hot Air Plasma Generated by Microwave Resonant Cavity

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Journal of Analytical Sciences, Methods and Instrumentation 2017年第4期7卷 93-115页

作者： Frédéric Marchal Nofel Merbahi Gaétan Wattieaux Alain Piquemal mohammed yousfi Université de Toulouse LAPLACE UPS CNRS INPT Toulouse France CEA DAM DIF Arpajon France

For the first time, absolute densities of atomic nitrogen in its ground state (N4S) have been measured in hot dry and humid air plasma columns under post-discharge regime. The determination of space-resolved absolute densities leads to obtain the dissociation degrees of molecular nitrogen in the plasma. The hot plasmas are generated inside an upstream gas-conditioning cell at 600 mbar when the air gas flow is directly injected at 10 slm in a microwave resonant cavity (2.45 GHz, 1 kW) placed in the downstream side. Density measurements based on laser induced fluorescence spectroscopy with two-photon excitation (TALIF), are more particularly performed along the radial and axial positions of the plasma column. Calibration of TALIF signals is performed in situ (i.e. in the same gas-conditioning cell but without plasma) using an air gas mixture containing krypton. Optical emission spectroscopy is considered to estimate the rotational gas temperature by adding a small amount of H2 in dry air to better detect OH (A-X) spectra. The rotational temperatures in humid air plasma column (50% of humidity) are larger than those of dry air plasma column by practically 30% near the nozzle of resonant cavity on the axis of the plasma column. This is partly due to attachment heating processes initiated by water vapor. A maximum of the measured absolute nitrogen density is also observed near the nozzle which is also larger for humid air plasma column. The obtained dissociation degrees of molecular nitrogen in both dry and humid air plasma along the air plasma column are lower than the cases where only thermodynamic equilibrium is assumed. This is characteristic of the absence of chemical and energetic equilibria not yet reached in the air plasma column dominated by recombination processes.

关键词： TALIF Atomic Nitrogen Density Measurement Hot Air Plasma Optical Emission Spectroscopy

Preliminary Palynostratigraphic Data on the Middle Albian-Lower Cenomanian of the Tarfaya Basin, Southwest Morocco

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Open Journal of Geology 2024年第4期14卷 548-568页

作者： Khaoula Chafai Touria Hssaida Wafaa Maatouf Mohamed Z. yousfi Sara Chakir Soukaina Jaydawi Hanane Khaffou Department of Geology Faculty of Sciences Ben M&#8217Sik University Hassan II Casablanca Morocco Department of Petroleum Laboratory Office National des Hydrocarbures et des Mines Rabat Morocco Department of Geology Faculty of Sciences Dhar El Mahraz Sidi Mohamed Ben Abdellah University Fes Morocco Department of Geology Faculty of Sciences Mohammed V University Rabat Morocco

The Tarfaya-Laayoune-Boujdour basin is of great interest to oil exploration;on this aspect, there has been exploration by the Moroccan National Office of Hydrocarbons and Mining, which has shown indices of oil and/or gas recorded in most wells drilled in the Moroccan Atlantic margin. FD-1 well, object of this study, is one of these wells located in the offshore Tarfaya-Laayoune-Boujdour basin. A palynological examination of the processed samples revealed the existence of organic palynomorphs, well conserved and rich in dinoflagellate cysts. The latter are composed of worldwide marker taxa of high stratigraphic resolutions. Thus, the middle upper Albian (3408 - 3408.5 m) is determined by the presence of Cribroperidinium tensiftense, Tehamadinium coummia, Spiniferella cornuta, Chichaouadinium vestitum, Dinopterygium alatum and Litosphaeridium arundum. The upper Albian (3406.5 - 3408 m) is characterized by the FOs of marker taxa: Cyclonephelium chabaca, Cribroperidinium auctificum and Chichaouadinium vestitum. Lastly, the upper Albian-lower Cenomanian transition is defined between 3404 m and 3406.50 m, as suggested by the FOs of Chichaouadinium boydii, Dinopterygium tuberculatum, Sepispinula ancorifera, Litosphaeridium conispinum, Prolixosphaeridium conulum and Xenascus ceratioides.

关键词： Morocco Tarfaya-Laayoune-Boujdour Basin Albian-Cenomanian Transition Dinoflagellate Cysts Palynostratigraphy

Enhancing optical absorption in visible light of ZnO co-doped with europium and promethium by first-principles study through modified Becke and Johnson potential scheme

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Journal of Rare Earths 2019年第4期37卷 416-421页

作者： A.G.El Hachimi M.L.Ould NE A.El yousfi A.Benyoussef A.El Kenz Laboratory of Condensed Matter and Interdisciplinary Sciences (LaMCScI) Associé Au CNRST (URAC 12) Département de Physique B.P.1014 Faculté des SciencesUniversité Mohammed V Hassan Ⅱ Academy of Science and Technology

By using first-principles calculations we studied the electronic, optical and magnetic properties of ZnO co-doped with Eu and Pm. In this calculation, we used Wien2 k code based on full potential linearized augmented plane waves(FP-LAPW) method with the modified Becke-Johnson(mBJ) approximation. This correction gives good band gap compared to experimental band gap. The introduction of Eu and Pm codoping leads to an increase in the band gap. Electrons can transit easily from the valence band to the conduction band, which results in an enhancement of visible light absorption in a wider absorption range. Absorption spectra reach a high value in visible and infrared light regions. With the significance of the obtained results, the studied compounds may potentially find spintronic and optoelectronic applications.

关键词： Zinc oxide Rare earth Density functional theory Modified Becke-Johnson Magnetic properties Spintronics

The Impact of Gastroesophageal Reflux on the Quality of Life: About a Series of 100 Patients at Fez University Hospital

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Open Journal of Gastroenterology 2019年第6期9卷 99-108页

作者： Houda Meyiz mohammed El Agheb Asmae Lamine Mounia El yousfi Nordin Aqodad Dafr Benajeh mohammed El Abkari Adil Ibrahimi Ihsane Mellouki Hepato-Gastroenterology Department Hassan II University Medical Center Fez Morocco Faculty of Medicine Sidi Mohammed Ben Abdellah University Fez Morocco

The gastroesophageal reflux disease (GERD) represents a major problem for public health because of its high prevalence. The chronic character of the symptoms can have a very important impact on the quality of life (QoL). The purpose of this study is to assess the impact of the GERD on the quality of life of our patients and to determine the main aggravating factors. Patients and Methods: This is a cross-sectional, observational study of 100 patients presenting signs of GERD in the gastroenterology department of the university medical center Hassan II-Fez, for a period of 3 months (October to December 2014). We used the Reflux-Qual short form (RQS®) to evaluate the QoL of our patients. Results: Over the study period, 100 patients were included. The average age of our patients was 47 years [20 - 75 years] with a sex-ratio F/M in 2.12. Among our patients, 20% (n = 20) were chronic cigarette smokers. The diagnosis of GERD was clinical in 75% of the cases (n = 75) and based on 24-hour pH monitoring in the remaining 25% (n = 25). Approximately 2/3 of the patients were receiving proton pump inhibitors (PPIs) treatment at the time of the questionnaire. The impairment of QoL was moderated to severe (RQS® p = 0.01), female sex (p = 0.03) and the frequency of symptoms (p = 0.001). Moreover, patients having a GERD that requiring a daily and continuous administration of PPIs had a lower index of RQS® (p = 0.001). The quality of life impairment was not associated with chronic cigarette smoking (p = 0.3). Conclusion: The impairment of the QoL was moderated to severe (RQS® < 16) for 2/3 of the patients (n = 62). This impairment was associated with elderly, female sex, frequency and in case of GERD requiring continuous administration of PPIs.

关键词： Gastroesophageal Reflux Reflux-Qual Short Form Quality of Life

Aortodigestive Fistula: A Rare Cause of Digestive Bleeding

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Case Reports in Clinical Medicine 2021年第4期10卷 126-132页

作者： Nada Lahmidani Mouna Figuigui Hakima Abid Mounia El yousfi mohammed El Abkari Sidi Adil Ibrahimi Dafr Allah Benajah Department of Gastroenterology University Hospital Hassan II Sidi Mohammed Ben Abdallah University Fez Morocco

Backgound: Aorto-digestive fistulas remain a fatal disease entity often occurring after vascular surgeries. Eso-gastro-duodenal endoscopy is essential to explore the upper digestive bleeding. The negativity of morphological examinations should not exclude the diagnosis. Diagnosis has benefited in recent years from developments in cross-sectional imaging: computed tomography (CT) and magnetic resonance imaging (MRI). The severity of bleeding is linked to the vital consequences (mortality close to 50% up to 100% in the absence of treatment), functional (30% amputation), and to the underlying infection itself correlated with the attack of the stent and the anastomosis. Patients: We report three cases of aorto-digestive fistulas treated at The University Hospital Hassan II to show the challenging diagnosis and therapeutic of such rare causes of upper digestive bleeding. Results: three patients were admitted to the emergency endoscopy unit for upper digestive bleeding, 2 of them had a medical history of Behcet Disease and two had past aortic aneurism surgery. The couple’s upper endoscopy and CT scan angiography made the diagnosis. Unfortunately, 2 patients died from fatal bleeding. Conclusion: Aortodigestive fistula is an extremely serious complication of aortic aneurisms and a rare cause of gastrointestinal bleeding. This diagnosis should be considered in any patient presenting with digestive bleeding with vascular disease or previous history of vascular stent.

关键词： Aorto Digestive Fistula Bleeding Endoscopy Primary

Peripheral Neuropathy under Infliximab Therapy: About One Case

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Open Journal of Gastroenterology 2020年第9期10卷 242-246页

作者： Fatima-Zahra Hamdoun Hakima Abid Nada Lahmidani Mounia El yousfi Dafr-Allah Benajah mohammed El Abkari Adil Ibrahimi Department of Hepato-Gastroenterology Hassan II University Hospital of Fez Faculty of Medicine University Sidi Mohammed Ben Abdelalh Fez Morocco

A-TNF inhibitors are increasingly used in various inflammatory disorders. Multiple side effects have been reported in recent years, particularly peripheral neuropathies. We report a case of axonal neuropathy occurring after the start of treatment with Infliximab. This is a 47 years old patient, followed for Crohn’s disease requiring treatment with Infliximab. Twenty-two weeks later, the patient presented a grade 4 of axonal neuropathy. We concluded to a medicinal sensitive neuropathy after elimination of other etiologies. Given the severity of the neurological symptoms, we decided to change the therapeutic class.

关键词： Crohn’s Disease Infliximab Peripheral Neuropathy

Endoscopic Treatment of Esophageal Achalasia: Experience of the Hepato-Gastroenterology Service of Fez

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Open Journal of Gastroenterology 2019年第8期9卷 164-173页

作者： Houda Meyiz Asmae Lamine Mounia El yousfi Nourdin Aqodad mohammed El Abkari Adil Ibrahimi Dafr Allah Benajeh Ihssane Mellouki Department of Hepato-Gastroenterology University Hospital Hassan II Fez Morocco Faculty of Medicine-Fez University Sidi Mohammed Ben Abdellah Fez Morocco

The achalasia is a rare primary esophageal motor disorder characterized by relaxation disorders of the lower esophageal sphincter and absence of the esophageal body peristalsis. Several studies suggest that the response to the endoscopic treatment depends on several predictors. The aim of our study was to evaluate the endoscopic treatment of esophageal achalasia and identify the predictive factors of endoscopic treatment response. Patients and Methods: This is a retrospective analytical study of 78 patients with achalasia, managed in the gastroenterology department of the university medical center Hassan II-Fez, during a period of 5 years (January 2009 to December 2014). The diagnosis of achalasia was retained on a set of clinical, endoscopic, manometric and radiological arguments. A graded dilation protocol starting with a 35 mm balloon three times for 30 seconds in progressive pressure between 5 and 8 psi was performed. We used the Eckardt score to evaluate the clinical remission. Results: During the study period, 78 patients were included. The average age of our patients was 47 years old [18 - 81] with a sex-ratio M/F of 1.05. The average of Eckardt score before dilation was 5.9 [3 - 9]. An average of 1.41 dilation sessions was performed per patient with 85.9% of the initial success rate (n = 67). Initial success without further dilation sessions was achieved in 55.1% of our patients (n = 43). A clinical recurrence requiring further dilation sessions was observed in 30.8% of the cases (n = 24). The average relapse time after first dilation success was 2.7 years, 75% occurs within the first year. Dilation failure was retained in 14 patients (17.9%) requiring surgery. Only one post-dilation perforation was noted. In multivariate analysis, only odynophagia and the number of dilatation sessions were factors of failure of the endoscopic dilation. Conclusion: Pneumatic dilation is a minimally morbid and effective procedure. Our work showed that odynophagia, and the num

关键词： Achalasia Pneumatic Dilatation Manometry Eckardt Score