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

Seasonal and regional occurrence of heat-resistant spore-forming bacteria in the course of ultra-high temperature milk production in Tunisia

International audienceSpore-forming bacteria, principally Bacillus species, are important contaminants of milk. Because of their high heat resistance, Bacillus species spores are capable of surviving the heat treatment process of milk and lead to spoilage of the final product. To determine the factors influencing the contamination of milk, spore-forming bacteria occurrence throughout the UHT milk production line during winter, spring, and summer was studied. The obtained results confirm that the total viable rate decreases rapidly throughout the production line of UHT milk showing the efficiency of thermal treatments used. However, the persistent high rate of spore-forming bacteria indicates their high heat resistance , especially in spring and summer. In addition, a significant variation of the quality of raw milk according to the location of the collecting centers was revealed. The molecular identification showed a high degree of diversity of heat-resistant Bacillus species, which are isolated from different milk samples. The distribution of Bacillus species in raw milk, stored milk, bactofuged milk, pasteurized milk, and UHT milk were 28, 10, 16, 13, and 33%, respectively. Six Bacillus spp. including Bacillus licheniformis (52.38%), Bacillus pumilus (9.52%), Bacillus sp. (4.76%), Bacillus sporothermodurans (4.76%), Terribacillus aidingensis (4.76%), and Paenibacillus sp. (4.76%) were identified in different milk samples

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

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

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

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

Automatiser la construction de règles de corrélation : prérequis et processus

National audienceLes systèmes d'entreprise sont aujourd'hui composés de plusieurs dizaines, centaines ou milliers d'entités communiquant potentiellement avec des machines externes inconnues. Dans ces systèmes de nombreux détecteurs, sondes et IDS sont déployés et inondent les systèmes de supervision de messages et d'alertes. La problématique d'un administrateur en charge de la supervision est alors de détecter des motifs d'attaques contre le système au sein de ce flot de notifications. Pour cela, il dispose d'outils de corrélation permettant d'identifier des scénarios complexes à partir de ces notifications de bas niveau. Cependant, la spécification de ces scénarios demande d'avoir au préalable construit les règles de corrélation adéquates. Ce papier se focalise sur une méthode de génération de règles de corrélation et des prérequis nécessaires à cette opération. Il évalue ensuite le travail requis pour obtenir de telles règles dans le cas d'un processus de génération automatisé

Final results of magnetic monopole searches with the MACRO experiment

We present the final results obtained by the MACRO experiment in the search for GUT magnetic monopoles in the penetrating cosmic radiation, for the range $4\times 10^{-5}< \beta < 1$. Several searches with all the MACRO sub-detectors (i.e. scintillation counters, limited streamer tubes and nuclear track detectors) were performed, both in stand alone and combined ways. No candidates were detected and a 90% Confidence Level (C.L.) upper limit to the local magnetic monopole flux was set at the level of $1.4\times 10^{-16}$ cm$^{-2}$ s$^{-1}$ sr$^{-1}$. This result is the first experimental limit obtained in direct searches which is well below the Parker bound in the whole $\beta$ range in which GUT magnetic monopoles are expected.Comment: 12 pages, Latex, 9 figures and 2 Table