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Modeling of a DC glow discharge in a neon–xenon gas mixture at low pressure and with metastable atom densities

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Plasma Science and Technology 2017年第9期19卷 66-72页

作者： A bouchikhi University of Sai'da Faculty of TechnologyDepartment of Electrical EngineeringSa'l'da 20000Algeria

The physical properties of Ne–Xe DC glow discharges at low pressure are reported for a gap length of 1 cm for the first time in the literature. The model deals specifically with the first three moments of Boltzmann＇s equation and includes the radiation processes and metastable atom densities. The spatio-temporal distributions of the electron and neon and xenon ion densities, the neon and xenon metastable atom densities, the electric potential and the electric field as well as the mean electron energy are presented at 1.5 Torr and 250 V. The current–voltage characteristic is shown at 3 Torr, and it is compared with previous work for pure neon gas. The model is validated theoretically and experimentally in the case of pure gas.

关键词： metastable Boltzmann validated gases cathode length excitation deals anode stationary

Two-Dimensional Numerical Simulation of the DC Glow Discharge in the Normal Mode and with Einstein’s Relation of Electron Diffusivity

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Plasma Science and Technology 2012年第11期14卷 965-973页

作者： A.bouchikhi University of Sada Faculty of the Sciences and TechnologyDepartment of the Electrical Engineering

This paper presents an investigation of a DC glow discharge at low pressure in the normal mode and with Einstein＇s relation of electron diffusivity. Two-dimensional distributions in Cartesian geometry are presented in the stationary state, including electric potential, electron and ion densities, longitudinal and transverse electrics fields as well as electron temperature. Our results are compared with those obtained in existing literature. The model used in this work is based on the first three moments of Boltzmann＇s equation. They serve as the continuity equation, the momentum transfer and the energy equations. The set of equations for charged particles presented in monatomic argon gas are coupled in a self-consistent way with Poisson＇s equation. A parametric study varying the cathode voltage, gas pressure, and secondary electron emission coefficient predicts many of the well-known features of DC discharges.

关键词： normal glow discharge Boltzmann's equation Poisson's equation electrondiffusivity Einstein's relation

Identification of the normal and abnormal glow discharge modes in a neon-xenon gas mixture at low pressure

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Plasma Science and Technology 2018年第11期20卷 70-75页

作者： B HECHELEF A bouchikhi University of Saida Faculty of Technology Department of Electrical Engineering Saida 20000 Algeria

In this paper, we focused on the identification of the normal and abnormal glow discharge modes in a neon-xenon gas mixture at low pressure. We considered four gas mixtures： 90%Ne-10%Xe, 80%Ne-20%Xe, 70%Ne-30%Xe and 50%Ne-50%Xe at 1.5 Torr. The range of the gap voltage is 150-500 V. A one-dimensional fluid model with multiple species was used in this work, and the metastable state of the atoms as well as the radiation effects were integrated into the model too. The input data changed for each percentage in the gas mixture, and was calculated by BOLSIG＋ software. The parameters of particle transport and their rate coefficients strictly depend on the mean electron energy. The results show that the neon ion density is negligible compared to the xenon ion density, mostly in the case of 50%Ne-50%Xe.

关键词： gas mixtures Boltzmann's equation Poisson's equation Blanc's law two-order fluid model

2D DC Subnormal Glow Discharge in Argon

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Plasma Science and Technology 2010年第1期12卷 59-66页

作者： A.bouchikhi A.HAMID University of Saida Faculty of Sciences and Technology Department of Electrical Engineering University of Sciences and Technology of Oran

A two-dimensional time-dependent fluid model was developed and used to describe a DC subnormal glow discharge in argon with Cartesian geometry. This configuration allows us to take into account the transverse expansion of the discharge. A hydrodynamic fluid model used in this paper is based on the moments of the Boltzmann transport equation. The resultant set of governing equations consists of continuity equations （fluxes and densities） for electrons and ions, an energy equation for electrons, and Poisson＇s equation. Simulation results are presented for the densities of charged particles, the electric voltage, the electric field, and the electron temperature of the discharge. The results were compared with those obtained in the literature.

关键词： subnormal glow discharge Boltzmann equation electron temperature Poisson's equation

广西来宾二叠系栖霞组黏土矿物和地球化学特征初步研究及地质意义

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地质科技情报 2011年第1期30卷 15-19页

作者： bouchikhi Hadjira 王夏马仲武伍明颜佳新中国地质大学生物地质与环境地质教育部重点实验室武汉430074 Department of Earth Sciences University Abou Bekr Belkaid Tlemcenalgeria13000 中南民族大学化学与材料学院武汉430074

研究了广西来宾铁桥剖面栖霞组的黏土矿物组合和地球化学特征的纵向变化特征。黏土矿物分析结果表明,栖霞组上部和下部地层中,黏土矿物含量较高,以伊利石、绿泥石为主,含少量的高岭石和蒙脱石;中部地层中黏土矿物含量较少。在电子显微镜... 详细信息

研究了广西来宾铁桥剖面栖霞组的黏土矿物组合和地球化学特征的纵向变化特征。黏土矿物分析结果表明,栖霞组上部和下部地层中,黏土矿物含量较高,以伊利石、绿泥石为主,含少量的高岭石和蒙脱石;中部地层中黏土矿物含量较少。在电子显微镜下,有些黏土矿物,如伊利石,发育在草莓状黄铁矿晶体之间,形成于早期成岩作用阶段。整体上黏土矿物成因与陆源碎屑物质输入有关。配套的地球化学分析表明,Al、Fe和Ti质量分数等反映陆源物质的指标,在栖霞组下部和上部质量分数较高,中部明显较低。上述黏土矿物分析和地球化学测试结果意味着该地区二叠纪栖霞期呈现一个明显的陆源碎屑物质输入旋回变化,早期和晚期陆源物质供应较明显,而中期较贫乏,可为该区进一步古地理研究提供重要参考。

关键词：栖霞组黏土矿物铁桥剖面陆源碎屑

Endoscopic Hemostatic Treatment of Gastric Varices during Pregnancy by Injection of Histoacryl

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Open Journal of Gastroenterology 2014年第4期4卷 149-151页

作者： Nora Bousfiha Najoua Bousfiha Chahrazad bouchikhi Abdelaziz Banani Adil Ibrahimi Nourdin Aqodad Service d’hépato-gastro-entérologie CHU Hassan II Fès Maroc Service de gynécologie-obstétrique 1 CHU Hassan II Fès Maroc

The occurrence of pregnancy is relatively rare in patients with portal hypertension, and has been reported as clinical cases. However, few studies have evaluated the effectiveness of injecting histoacryl during pregnancy. The choice of treatment for varicose bleeding during pregnancy has been described in the literature based on the elastic ligature. We report the second case, to our knowledge, of treatment of bleeding gastric varices by injection of histoacryl with good maternal and fetal development.

关键词： Gastric Varices Pregnancy Hystoacryl

Obstetric recto-vaginal fistula: What technique to use?

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Open Journal of Obstetrics and Gynecology 2013年第5期3卷 441-444页

作者： Sanaa Errarhay Samia Mahmoud Najia Hmidani Hanane Saadi Chahrazed bouchikhi Abdelaziz Banani Department of Gynecology and Obstetrics CHU Hassan II Fez Morroco

Objective: The recto-vaginal fistula is an abnormal communication between the previous wall of the rectum and the posterior face of the vagina through the recto-vaginal septum. They are often due to the obstetric traumas and they can be of post-surgical origin. Methods: We report five cases of patients with obstetric recto-vaginal fistula and all of the patients have surgical intervention with a resection of the fistulous route and rectal wall. Results: The patient did not present any recidivating and the evolution is satisfactory without complications or recidivating. Conclusion: The treatment of recto-vaginal fistula is often difficult exposed to recurrence;and the therapeutic indications must be adapted to every type of fistula by taking into account its size, its location and its etiology.

关键词： Recto-Vaginal Obstetric Trauma Pelvic Trauma Treatment

Ovarian desmoplastic small round cell tumors: Prognosis is poor! Case report

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Open Journal of Obstetrics and Gynecology 2013年第2期3卷 235-238页

作者： Hanane Saadi Hind Fatmi Nissrine Mamouni Sanaa Errarhay Chahrazed bouchikhi Afaf Amarti Abdelaziz Banani Department of Gynecology Obstetrics I University Hospital Hassan II Fez Morocco Department of Pathology University Hospital Hassan II Fez Morocco

The tumor desmoplastic small round cell in women is rare. Ovarian its location is exceptional. We report a patient of 20 years, the originalNorth Africawho consulted for an increase in abdominal volume with impaired general condition. Pelvic ultrasonography and computed tomography were in favor of multiple peritoneal masses with ascites. After surgical exploration, the histological and immunohistochemical data for diagnosis small round cell desmoplastic tumor of ovarian the patient was a candidate for poly chemotherapy but she was died a month later. Diagnosis relies on histological and immunohistochemical data. The demonstration of a nonrandom translocation t (11;22) (p13;q12) is specific for the disease. The management is multidisciplinary and combining surgery, a poly aggressive chemotherapy and radiotherapy. The prognosis remains poor.

关键词： Small Round Cell Desmoplastic Tumor Ovarian Diagnosis Treatment Prognosis

Neuroendocrine tumors of the ovary: What support?

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Open Journal of Obstetrics and Gynecology 2013年第10期3卷 739-742页

作者： H. Al Moubaker S. Errarhay S. Mahmoud Amal Bennani C. bouchikhi Affaf Amarti A. Banani Service Gynecology Obstetricsi Chuhassan Iifes Fez Morocco Service Pathological Anatomy Chuhassan Iifes Fez Morocco

Neuroendocrine tumors of the ovary tumors are little known and infrequent. They are made up of cells appearing in the endocrine and nervous systems. These tumors are rare, but most of them are very aggressive, especially when they are diagnosed beyond FIGO Stage I. The distinction among the different subtypes is difficult and requires efficient techniques. Symptoms of neuroendocrine tumors are often nonspecific (redness in the face, diarrhea, asthma, abdominal pain and etc.,) and confused with more common diseases. Misdiagnosis is often asked: menopause or irritable bowel syndrome. Often the correct diagnosis is not made until years after the onset of symptoms. The relative rarity of these diseases and the lack of specificity of the symptoms make them often be diagnosed several years after onset. Fortunately, science has made significant advances in the diagnosis and treatment of neuroendocrine tumors. We report the case of a woman of 54 years, with abdominopelvic mass, in whom abdominal ultrasound revealed a mass avascular tissue Doppler taking the screen. The abdominopelvic CT showed a large cystic mass solido—abdominopelvic whose origin is difficult to determine. The patient underwent an exploratory laparotomy. Anapath the results of the right ovary were in favor of a well-differentiated neuroendocrine lesion.

关键词： Tumor Neuroendocrine-Diagnosis-Treatment