Erosion is one of the important unlikely problems in oil refining industry that produces many damages and values to refining parts. In other part stop of refining operation for repairing is very expensive. Many erosions are happened in refining operations when equipments are placed to atmosphere, Powerful acids, eruption gases, hydrocarbon vampires and high temperature make very complex situation in oil refining industry, Monotonous erosion, cavity erosion rubbing erosion, stress split are more common erosions in oil refining systems that will be search in this survey.
This paper presents the comparison of Unipolar Inverted Sine Carrier Pulse Width Modulation (UISCPWM) techniques for the Cascaded Multi Level Inverter (CMLI). Due to switch combination redundancies, there are certain degrees of freedom to generate the multilevel AC output voltage. This paper presents the use of Control Freedom Degree (CFD) combination. The effectiveness of the pulse width modulation strategies developed using CFD are demonstrated using simulation. The results indicate that the chosen five level inverter triggered by the developed UISC phase shift PWM and UISC variable frequency PWM strategy with sine and stepped wave references and UISC alternate phase opposition disposition PWM strategy with 60 degree reference exhibit reduced harmonics and UISC carrier overlapping PWM provides higher fundamental RMS output voltage for all three chosen references. Simulations are performed using MATLAB-SIMULINK.
The access to drinking water, in particular in the rural areas and semi-rural in Ivory Coast, constitutes a paramount factor in economic development, the improvement of the standard of living of the populations and their stabilization. The present study aims to raise the unequal distribution of the water supply points for the area of Daoukro and to make a contribution in the research of the zones favorable with the establishment of the productive water supply points in order to allow a good cover of the water needs. The adopted methodological approach is summarized in two stages: initially design of the chart of the water requirements (the access to drinking water) which highlights the zones of deficits followed by the cartography of the sites of establishment of the future water supply points. The knowledge of the space distribution of the population and amongst water supply point by locality made it possible to calculate the access to drinking water of the populations. The analysis of the chart set of themes of the storage areas reveals that nearly 80% of the total surface areas are occupied by zones favorable to the existence of groundwater. The various suitable zones with the establishment of work to large flows were charted and more than 150 sites favorable to the future establishments were selected.
Until the eighties, Tunisia opted for a policy of import substitution and of protection of domestic market from foreign competition. Within this framework, the State controlled most of the economy such as: control of interest rates, price controls, maintaining an overvalued exchange rate, the maintenance of quantitative restrictions and tariffs high customs. In recent years, most developing countries, as Tunisia, adopt economic development strategies increasingly liberal and this by opening up their domestic markets to international trade. Indeed, the context in which the Tunisian economy is expected to move is difficult, and the challenge on its competitiveness is important. The analysis detected that Tunisia is succumbing to the foreign competition, which it faces on the world and European market. Indeed, we have revealed that Tunisian competitiveness is doped, especially, by the depreciation policy of the Tunisian Dinar and his compression policy of wages but, to a lesser extent, impelled by the real competitive potential to knowing the productivity gains. Consequently, and by the insignificant influence of structural component of the Tunisian competitiveness, it is primordial to revise its strategy of competitiveness, to be directed to the construction of a competitive potential, built on a durable basis, and un-doped by the exogenic measures, such the use of depreciation's weapon.
Control of different network fractures is an important tool in the Mining Research in the Birimian of West Africa. The objective of this work is to highlight the fractures and major formations of central-east of Ivory Coast, using Landsat 7 ETM+ images. We have extracted lineaments and the hydrographical network from an analogic analysis supplemented by numerical analysis using directional filters. Next, we determined the limits of lithological using textures and colors. A sketch map of lithostructural was thus obtained. Several directions of major fractures were mapped. These directions are: sinistral submeridional N00
In this paper, we use the fractional q-Integrals on a specific time scales to generate some new inequalities of Gruss type. For this paper, some classical results can be deduced as some special case.
Spectrum sensing is the key component of cognitive radio technology. Spectrum sensing is a tough task because of shadowing, fading, and time-varying nature of wireless channels. However, detection is compromised when a user experiences shadowing or fading effects. In such cases, user cannot distinguish between an unused band and a deep fade. Thus, cooperative spectrum sensing is proposed to optimize the sensing performance. We focus performance of cooperative spectrum sensing over Rayleigh and Nakagami fading channel with comparable non-fading AWGN channel in cognitive radio. This paper presents a simulation comparison of these fading channels based on fusion rule OR-rule, AND-rule and MAJORITY-rule. We observe that spectrum sensing is harder in presence of Rayleigh and Nakagami fading and performance of energy detection degrades more in Nakagami channels than Rayleigh channel and non-fading AWGN channel.
The aim of the current study is to see the changes in the amount of benefit management regarding the firms whose liabilities increase to a large extent. The managers of these kinds of firms normally have more motivations to satisfy credit providers through profit management. But it seems that auditors and financial providers' more attention to these firms' leads to having more regular managers and decreasing profit management performance. The tested sample includes 136 firms among the accepted ones in Iran Stock Exchange considering a period of eight years from the beginning of 2000 to the end of 2007. In order to estimate the rate of profit management performance by the use of Jones adjusted model, the optional committed items were calculated. The hypotheses were tested via regression method. The results demonstrated that the increase of most liabilities causes the decrease of profit management performance. In fact, liability makes managers have less access to free cash flows in order to pay the liability and its interest; therefore, they cannot take advantage of the opportunities such as non-optimization investment, extra cost tolerance and earning waste. In other words, the more the liabilities increase, the more regular the managers perform.
This research paper aims to build a financial stress index for Moroccan banking system. Inspired from a thesis project, this index based on a combination of ratios and other indicators may be an important way, beside stress tests, to purchase the evolution of Moroccan banking system. A normal development of this approach will help to forecast periods of crisis and therefore help avoid them.
In this paper we analyze the combine influence of radiation and dissipation on the convective heat and mass transfer flow of a viscous fluid through a porous medium in a rectangular cavity using Darcy model. Making use of the incompressibility the governing non-linear coupled equations for the momentum, energy and diffusion are derived in terms of the non-dimensional stream function, temperature and concentration. The Galerkin finite element analysis with linear triangular elements is used to obtain the Global stiffness matrices for the values of stream function, temperature and concentration. These coupled matrices are solved using iterative procedure and expressions for the stream function, temperature and concentration are obtained as linear combinations of the shape functions. The behavior of temperature, concentration, Nusselt number and Sherwood number are discussed computationally for different values of the governing Parameters Ra, α, N, N1, Sc, S0 and Ec.