Statcom integration in a power grid to enhance voltage stability

To solve load growth of an existing electrical system, we at first inject the power in system by building new electrical plants as wind, solar or thermal. And secondly in year 2030, when the system is so meshed, some customers are far away at production stations. We propose the installation of FACTS devices to enhance voltage in stability margins of power system under study. The power flow analysis using Newton Raphson method was running on Matlab and PSS/E Simulator. The results of simulation without STATCOM show the most affected buses. To improve the voltage for all these buses, reduce the power mismatches and tranmit more ative power, we insert STATCOM. STATCOM is a shunt connected FACTS application which facilitate the fast voltage control, the reactive power control and reduce the harmonics in a power system

Optimization for Electric Power Load Forecast

Load flow studies are one of the most important aspects of power system planning and operation. The main information obtained from this study comprises the magnitudes and phase angles of load bus voltages, reactive powers at generators buses, real and reactive power flow on transmission lines, other variables being known. To solve the problem of load flow, we use the iterative method, of Newton-Raphson. Analysis of the found results using numerical method programmed on the Matlab software and PSS/E Simulator lead us to seek means of controlling the reactive powers and the bus voltages of the Nouakchott power grid in 2030 year. In our case, we projected the demand forecast at 2015 to 2030 years. To solve the growing demand we injected the power plants in the system firstly and secondly when the production and energy demand are difficult to match due to lack of energy infrastructures in 2030.It is proposed to install a FACTS (Flexible Alternative Current Transmission Systems) system at these buses to compensate or provide reactive power in order to maintain a better voltage profile and transmit more power to customers

A rare neuronal tumor of the cerebellum with myoid features

We report an extremely rare tumor presenting with myoid features in the left cerebellar hemisphere in a 62-year-old man. This tumor consisted of medium to large round cells with focal lipomatous and myoid differentiation. Immunohistochemically, the tumor cells expressed synaptophysin, GFAP (glial fibrillary acidic protein) and focally desmin. From these findings, we concluded that this tumor was a liponeurocytoma with myoid features. To the best of our knowledge, this report constitutes the second described case of liponeurocytoma with myoid differentiation in the cerebellum

Les métastases ovariennes d’origine biliaire: 2 cas avec revue de la littérature

Les ovaires constituent un site fréquent de métastases. L'origine gastrique prédomine. Les métastases ovariennes d'origine biliaire sont rarement rapportées dans la littérature. Les auteurs rapportent deux cas de   métastases ovariennes d'origine vésiculaire chez des patientes âgées respectivement de 63 et 40 ans. Le diagnostic de ces métastases ovariennes était concomitant avec le cancer d'origine dans le premier cas, et a survenu à distance de l'atteinte initiale dans le deuxième cas. Le diagnostic est suggéré sur les données radiologiques et confirmé histologiquement. Les métastases ovariennes d'origine biliaire sont rarement rapportées dans la littérature. L'atteinte ovarienne pose un problème de diagnostic différentiel avec une atteinte ovarienne primitive surtout si l'atteinte ovarienne précède les manifestations biliaires. L'imagerie joue un rôle important et oriente sur le caractère secondaire de l'atteinte ovarienne

Time variations in the deep underground muon flux measured by MACRO

More than 30 million of high-energy muons collected with the MACRO detector at the underground Gran Sasso Laboratory have been used to search for flux variations of different natures. Two kinds of studies were carried out: search for periodic variations and for the occurrence of clusters of events. Different analysis methods, including Lomb-Scargle spectral analysis and Scan Test statistics have been applied to the data.Comment: 6 pages, 4 EPS figures. Talk given at the 29th ICRC, Pune, India, 3-10 August 200

Méningo-vascularite bactérienne révélant un adénome hypophysaire

Un macroadénome à prolactine se présente généralement par un syndrome hormonal associé à un syndrome tumoral. Une méningite bactérienne compliquant un macroprolactinome en dehors de toute thérapie médicale ou chirurgicale est rarement rapporté dans la littérature. Mme R.C âgée de 48 ans s'est présentée aux urgences pour trouble de conscience fébrile. La ponction lombaire a révélé une méningite  bactérienne. L'imagerie cérébrale a mis en évidence un aspect de vascularite cérébrale et un processus de la loge sellaire avec lyse du plancher faisant évoquer une brèche ostéoméningée. Le bilan biologique a montré une hyperprolactinémie à 200 mg/dl. La patiente est mise sous antibiothérapie à dose méningée et une corticothérapie associée à un traitement par la Cabergoline. Le traitement chirurgical de la brèche ostéoméningée s'est fait par voie endonasale. L'évolution est marquée par une nette amélioration clinique et biologique et l'absence de récidive de la méningite après un recul de 14 mois. Un macroprolactinome peut  provoquer une brèche ostéoméningée en dehors de tout traitement médical ou chirurgical et avoir comme première manifestation une méningite infectieuse

Time variations in the deep underground muon flux

More than 35 million high-energy muons collected with the MACRO detector at the underground Gran Sasso Laboratory have been used to search for flux variations of different nature. Two kinds of studies were carried out: a search for the occurrence of clusters of events and a search for periodic variations. Different analysis methods, including the Scan Statistics test and the Lomb-Scargle spectral analysis have been applied to the data.Comment: 7 pages, 5 figures, accepted by EP

Homogeneous Grafting of New Amido Groups onto Hydroxyethyl Cellulose Acetate Microfibrils: Solubility Study

Attempts to modify the surface of hydroxyethyl cellulose acetate (HECA-DSAC ~1.5) microfibrils were made using amine terminated molecules. First, the amine compounds were reacted with sebacoyl chloride in nonstoichiometry ratio in order to obtain a monoadduct chloride such as ClCO-(CH2)8-CONHR. Then the resulted derivatives were coupled with hydrophobic hydroxyethyl cellulose acetate (HECA) by a condensation reaction in homogenous medium using triethyl amine (N(C2H5)3) in THF. The products were characterized by FTIR, 1H NMR, 13C NMR, and DRX, and thermal proprieties were also determined. The X-ray diffraction showed that the crystallinity of the amido esters obtained depends on both the degree of substitution and the nature of the graft moiety. The solubility study was based on the determination of the Flory–Huggins interaction parameters (χ) using the partial Hansen solubility parameters (HSP) and that were calculated from the Van Krevlen–Hoftyze (VKH) method and the T. Lindvig approximation. Keywords: cellulose; microfibrils; amidation; Hansen solubility; Flory–Huggins parameters