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Gabes, Tunisia

Sebri M.,University of Monastir | Ben-Salha O.,Gabes University | Ben-Salha O.,International Finance Group
Renewable and Sustainable Energy Reviews | Year: 2014

The current study investigates the causal relationship between economic growth and renewable energy consumption in the BRICS countries over the period 1971-2010 within a multivariate framework. The ARDL bounds testing approach to cointegration and vector error correction model (VECM) are used to examine the long-run and causal relationships between economic growth, renewable energy consumption, trade openness and carbon dioxide emissions. Empirical evidence shows that, based on the ARDL estimates, there exist long-run equilibrium relationships among the competing variables. Regarding the VECM results, bi-directional Granger causality exists between economic growth and renewable energy consumption, suggesting the feedback hypothesis, which can explain the role of renewable energy in stimulating economic growth in BRICS countries. © 2014 Elsevier Ltd. Source

This paper presents a practical method to solve the problem of global output feedback tracking trajectories for a class of Euler-Lagrange systems when the variables of velocity are the unmeasured part of the state. We exhibited a new output feedback control scheme, which globally exponentially stabilize trajectories. It relies on the determination of a change of coordinates which gives to the systems a triangular form. Results are illustrated on the academic example of the two-link direct drive robot manipulator. © Springer Science+Business Media B.V. 2009. Source

The scarcity of surface water resources in arid and semi-arid regions from North African countries contributes to the considerable increase of groundwater exploitation, which leads to the development of hydrogeological studies. However, due to the lack of hydrodynamic data in these regions, these studies focus more and more on the geochemical and environmental isotope techniques to insure a better understanding of the hydrodynamic functioning of subsurface systems. In this study, which interests an important unconfined aquifer in central Tunisia, tritium data and chloride mass balance (CMB) method were applied in order to (1) understand the mode of recharge of this aquifer and (2) obtain a reliable estimation of its recharge amount as well as (3) estimate its annual renewal rate. It has been demonstrated that the shallow groundwaters are classified into two groups according to their tritium contents. The first group includes wells located mainly downstream and highlights the significant role of the post-nuclear lineal recharge through Wadis courses. The second group encloses wells located practically overall the rest of the basin and refers to relatively modern waters originated from areal recharge of present-day rainfall. Based on the CMB method, the recharge to this unconfined aquifer is estimated to 31.7 mm year-1, which corresponds to 10.5% of the total rainfall. The annual renewal rate of groundwater, evaluated based on the tritium contents, is up to 16%. © 2009 Springer-Verlag. Source

The aquifer system in the Tunisian Chotts region is composed mainly of two aquifers: the upper confined/unconfined Complexe Terminal and the deeper confined Continental Intercalaire aquifer. The deep Continental Intercalaire thermal water represents approximately 20% of agricultural water supply in southern Tunisia. Its temperature varies between 46 and 73.°C, and it is mainly used for heating greenhouses and irrigation of oases. The non-thermal water (20-35.°C) is pumped from the Complexe Terminal aquifer with an average depth of 300. m. The Continental Intercalaire geothermal field is generally considered a thermal energy resource and should be evaluated for adequate purposes in the study area. Different chemical geothermometers were used in this work to assess the highest temperature that can be found in the Continental Intercalaire aquifer. Temperature values varying between 95 and 133.°C were obtained by using a Na-Li geothermometer. The multiple mineral equilibrium approach yielded a temperature of 87 to 112°C. © 2011 Elsevier Ltd. Source

Nasri W.,Gabes University
Journal of Enterprise Information Management | Year: 2011

The purpose of this study is to investigate the degree of knowledge of competitive intelligence in Tunisian companies. Design/methodology/approach- This exploratory study was conducted using semi-in-depth interviews and focus group with six executives in six companies in Tunisia. Three sectors were chosen for this study: communication technologies, manufacturing and commercial retailing. These companies are prevalent in Tunisia and are very different. Findings: The results show that Tunisian managers are conscious of the importance of competitive intelligence in the management of their companies. Second, managers believe that internal sources of information are more valuable than external sources information and personal source information is deemed most valuable. Third, the results of the process and structure questions indicate that companies may not yet be investing appropriately in building the internal infrastructure required for fully effective intelligence efficacy. Finally, this practice is not organised in a separate department and, if it is mostly done in the marketing department. Practical implications: To know and develop this practice, a company must, on the one hand, build internal competitive intelligence process. On the other hand, develop a sensitisation programme that is continuous and that should focus on telling employees what competitive intelligence is, what they can, and should, contribute and demonstrate the value in sharing information. Originality/value: This study is the first to investigate competitive intelligence in Tunisia. The results lead to a number of recommendations to develop competitive intelligence in Tunisian companies. Various methods are proposed including awareness and training program, recognising by managers the value of competitive intelligence as an important tool to develop competitive intelligence. © Emerald Group Publishing Limited. Source

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