317 research outputs found
Applications of generalized Ky Fan's matching theorem in minimax and variational inequality
No full textWe present some application of the generalized Ky Fan's Matching Theorem stated by Chebbi, Gourdel and Hammami in minimax and variational inequalities using a generalized coercivity type condition for correspondences defined in L-space.L-structures, L-spaces, L-KKM correspondences, L-coercing family, minimax and variational inequalities.
Relations phenetique des populations iberomaurusiennes de l'Afrique du Nord avec celles de la fin du Pléistocène-début de l'Holocène en Eurasie.
No full textCoppa A., Candilio F., Lucci M., Mehdi M., Oujaa A., Petrone P.P., Roudesli-Chebbi S., Vargiu R. 2009. Relations phenetique des populations iberomaurusiennes de l'Afrique du Nord avec celles de la fin du Pléistocène-début de l'Holocène en Eurasie. Société d'Anthropologie de Paris 3rd Jubilee International Congress, Paris 26 - 30 janvier 2009. Bulletins et Mémoires de la Société d’Anthropologie de Paris, n.s., t. 20, 2008
Agricultural and non-agricultural outputs and energy consumption in Tunisia: empirical evidences from cointegration and causality
No full textThis short paper investigates the cointegration and causality link between energy consumption and agricultural, non-agricultural outputs (manufacturing sector and services sector) and overall gross domestic product in Tunisia for 1971-2003 period. Empirical results suggest that there is only unidirectional causality running from agricultural and non-agricultural sectors to energy consumption as well as from overall GDP growth to energy consumption. This unidirectional causality signifies a less energy dependent economy and suggests that it is sectoral growth that drives the energy consumption in Tunisia and not vice versa. Empirical results suggest also that Tunisian agricultural sector growth does not depend on energy, and high consumption of energy do not implies more productivity in the short run for this sector.energy consumption, output growth, causality, cointegration, Tunisia, Resource /Energy Economics and Policy,
Intersection and minimax inequality with a generalized coercivity in h-spaces
No full textWe define a generalized coercivity type condition for correspondence defined on atopological vector space endowed with a generalized convex structure. An extension of the Fan’smatching theorem is obtained and used to prove results on coincidence, fixed point and minimaxinequality with a weakned compactness condition.Corresponding Author:
Dr. Souhail Chebbi, Associate Professor, Department of Mathematics, College of Sciences, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia. Email: [email protected]
Improvement of the integration of a grid-connected wind-photovoltaic hybrid system
No full textThis paper presents control strategies for the integration of a grid-connected wind-photovoltaic hybrid system via adaptation converters connected to a common DC bus. For both wind and solar system, adequate control algorithms have been implemented for the maximum power extraction. The grid side converter has been connected to the point of common coupling (PPC) through an RL filter. The control of the grid side converter (GSC) was made in order to control the power quality and quantity of the feed power to the grid. At the DC bus, a PI-regulation control was adopted to overcome the ripples caused by the power flow. Performances of the adopted control laws have been evaluated by MATLAB/Simulink simulations. © 2013 IEEE
Polycyclic aromatic hydrocarbon degradation and biosurfactant production by a newly isolated Pseudomonas sp. strain from used motor oil-contaminated soil
No full textThe aim of this study was to isolate and characterize a newly isolated bacterium, designated strain W10, a polycyclic aromatic hydrocarbon (PAHs) degrader and biosurfactant producer, belonged to Pseudomonas genus and closely related to Pseudomonas aeruginosa, with the 16 rRNA gene sequence similarity of 99.1%. Based on GC-MS analyses, it degraded around 80% of phenanthrene, used as the sole carbon and energy source, at an initial concentration of 200 mg l−1, after 30 days of incubation at 37 °C and 180 rpm, reducing the surface tension (ST) from 56.1 to 42 mN m−1 after 4 days of incubation. Furthermore, strain W10 utilized about 10%, 20%, 90%, and 99% of hexadecane (C16), pyrene, fluoranthene, and crude oil, respectively, after 30 days of incubation at 37 °C and 180 rpm. During the growth of strain W10 on phenanthrene and fluoranthene, some metabolites were identified, supporting the biodegradation pathways of the two PAHs. Interestingly, strain W10 showed also a significant potential to produce surface-active agents reducing the surface tension to 32 mN m−1 and reaching a production around 2 g l−1 after 48 h of incubation, in the presence of olive oil (1%,v/v) as substrate, at 37 °C and 180 rpm. Its biosurfactant, namely BSW10, showed an interesting emulsification activity and a high stability over a wide range of salinity (0–150 g l−1), temperature (0–100 °C), pH (2–12) and thus a promising abilities in used motor oil and crude oil removal from contaminated soils. Overall, these results provide evidence that strain W10 and its biosurfactant (BSW10) could be potential candidates for further bioremediation applications
Isolation and characterization of a newly naphthalene-degrading Halomonas pacifica, strain Cnaph3: biodegradation and biosurfactant production studies
No full textA newly marine Halomonas pacifica strain Cnaph3 was isolated, as a naphthalene degrader and biosurfactant producer, from contaminated seawater collected in Ataya’s fishing harbor, located in Kerkennah Islands, Tunisia. Chromatography flame ionization detector analysis revealed that 98.8% of naphthalene (200 mg/L) was degraded after 7 days of incubation, at 30 g/L NaCl and 37 °C. Strain Cnaph3 showed also a noticeable capacity to grow on a wide range of aliphatic, aromatic, and complex hydrocarbons. Interestingly, strain Cnaph3 showed a significant potential to produce biosurfactants in the presence of all tested substrates, particularly on glycerol (1%, v/v). Electrospray ionization analysis of the biosurfactant, designated Bios-Cnaph3, suggested a lipopeptide composition. The critical micelle concentration of Bios-Cnaph3 was about 500 mg/L. At this concentration, the surface tension of the water was reduced to 27.6 mN/m. Furthermore, Bios-Cnaph3 displayed interesting stabilities over a wide range of temperatures (4–105 °C), salinities (0–100 g/L NaCl), and pH (2.2–12.5). In addition, it showed promising capacities to remove used motor oil from contaminated soils. The biodegradation and biosurfactant-production potential of the Halomonas sp. strain Cnaph3 would present this strain as a favorite agent for bioremediation of hydrocarbon-contaminated sites under saline conditions
Analysis of renewable energy power systems: Reliability and flexibility during unbalanced network fault
No full textDue to different concerns, renewable energies stand out as an opportunity for a sustainable future. Wind/Photovoltaic Hybrid Systems are one important type of renewable energy power systems. In order to increase renewable energies integration rate, this chapter proposes a utility interactive grid-connected wind-PV hybrid system with storage batteries. Facing modern electricity industries, the hybrid system considers the dispatch-ability and the quality of its power injection into the grid. The adopted modeling approach has been based on energy exchange considerations taking into account the converters structures. Particular attention has been given to cases where the hybrid system is connected to an unbalanced grid. This chapter develops a new control strategy, which aims to isolate the hybrid system of the adverse impact of the grid fault. The results point out thoroughly the applicability of the proposed control scheme under unbalanced grid conditions
A moderately thermophilic and mercaptan-degrading Bacillus licheniformis strain CAN55 isolated from gas-washing wastewaters of the phosphate industry, Tunisia
No full textA moderately thermophilic bacterium, designated strain CAN55, was isolated from the gas-washing wastewaters of the phosphate industry, located in Sfax, Tunisia, after enrichment on 1-decanethiol, a mercaptan used as the sole carbon and energy source. Strain CAN55 belonged to the Bacillus genus and was closely related to Bacillus licheniformis, with 16S rRNA gene sequence similarity of 99.2%. It was able to degrade 83% of 1-decanethiol (3mM), and 39% of decyl disulfide, the product of spontaneous autoxidation, after 14 days of incubation at 55°C, and without yeast extract added. Strain CAN55 was also capable of degrading 70% of 1-dodecanethiol (3mM) after 14 days of incubation at 55°C. During the growth on decanethiol and dodecanethiol, the decrease of surface tensions of cell-free culture supernatants from 55.1 to 40mN/m and from 56.1 to 41mN/m, respectively, after 26h of incubation at 55°C, was an agreement with the production of biosurfactant(s). In addition, strain CAN55 degraded 1-heptanethiol and cyclohexylmercaptan thus suggesting that this isolate may be useful for the bioremediation of mercaptan contaminated sites. © 2014
A methodology for boosting circular economy in olive oil and wine sectors: opportunities for the Italian competitiveness through eco-innovation strategies
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