IJE_Vol 03 N 01
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Item The relationship between the compressive strength and ultrasonic pulse velocity concrete with fibers exposed to high temperatures(جامعة الوادي - university of el oued, 2018-04-11) Hassiba, Belaribi; Mekki, Mellas; Farid, RahmaniThe paper analyses the effects of high temperatures on the concrete residual strength using ultrasonic velocity (UPV). An experimental investigation was conducted to study the relationship between UPV residual data and compressive strength of concrete with different mixture proportions, cubic specimens with water-cement ratio of 0.35. They were heated in an electric furnace at temperatures ranging from 200°C to 600°C. In this experiment a comparison was made between the four groups which include two types of fibers steel 0,19%, 0,25% and 0,5%, polypropylene: 0,05%, 0,11% 0,16 % by volume. Cube specimens were tested in order to determine ultrasonic velocity. The compressive strength was tested too. According to the results, relations were established between ultrasonic velocity in the specimens and the compressive strength at different temperature and the range of the velocity of the waves were also determined for this kind of concrete. Result of the test showed that UPV test can be successfully used in order to verify the consistency of structures damaged by fireItem Proposed Algorithm MPPT for Photovoltaic System(جامعة الوادي - university of el oued, 2018-06-26) Bechouat, Mohcene; Sedraoui, ,Moussa; Kahla, SamiA proposed algorithm MPPT (Maximum Power Point Tracking) is proposed in this paper. When the insolation change rapidly, the P&O (Perturb and Observe) algorithm is used to adjust the operating point of the PV (Photovoltaic) array close to the MPP (Maximum Power Point) for fast tracking; also, the INC (Incremental Conductance) algorithm and the fuzzy controller skip drawbacks of the P&O algorithm by decreasing oscillations around the MPP and the underestimated. In addition, to improve the control precision, the effectiveness of proposed algorithm is validated by simulation using Matlab/Simulink, the simulation results show that the proposed algorithm tracks the MPP quickly, reduces the oscillation around the MPP effectively and improves the energy conversion efficiency of the PV panel.Item Modeling Electric Field and Potential Distribution of an Model of Insulator in Two Dimensions by the Finite Element Method(جامعة الوادي - university of el oued, 2018-05-25) M’ziou, Nassima; Benguesmia, HaniHani; Rahali, HilalThe electrical effects can be written by two magnitudes the field and the electrostatic potential, for the determination of the distribution of the field and the electric potential along the leakage distance of the polluted insulator, the comsol multiphysics software based on the finite element method will be used. The objective of this paper is the modeling electric field and potential distribution in Two Dimensions by the Finite Element Method on a model of insulator simulating the 1512L outdoor insulator used by the Algerian company of electricity and gas (SONELGAZ). This model is under different conductivity, applied voltage, position of clean layer and width of clean layer. The computer simulations are carried out by using the COMSOL multiphysics software. This paper describes how Comsol Multiphysics have been used for modeling of the insulator using electrostatic 2D simulations in the AC/DC module. Numerical results showed a good agreementItem Impact of fuel energy prices in Tunisia(جامعة الوادي - university of el oued, 2018-05-30) Jebali, assaad; . Kacem, AnisThe policy of subsidizing petroleum derivatives in Tunisia distorts the real prices of goods and services. It does not take care on environment. There is no serious fiscal policies to reduce pollution generated by energy products. The calculation of the correlation matrix between different macroeconomic aggregates does not give a negative effect of oil prices on national GDP. However, this result is serious, because the impact on economic (performance) is hidden, affecting first the general level of prices, unemployment and inflation. Instability of oil prices has no apparent impact. This fact and instability make many difficulties to manage prices and inflation after revolution. Impact on GDP passes through Economic Vulnerability Indicator (EVI) and agricultural sector.Item GPVDM simulation of layer thickness effect on power conversion efficiency of CH3NH3PbI3 based planar heterojunction solar cell(جامعة الوادي - university of el oued, 2018-06-25) Hima, A; Khechekhouche, A; Kemerchou, I; Lakhdar, N; Benhaoua, B; Rogti, F; Telli, I; Saadoun, APerovskite-based solar cell technologies have been a very attractive area of research in recent years. Organic-inorganic perovskite materials are in an increased evolution in power conversion efficiency. Inorganic materials have been tested at the laboratory level but their power conversion efficiency is still limited. In this paper, we used the GPVDM software to study the effect of some parameters on power conversion efficiency in a planar heterojunction solar cell based on CH3NH3PbI3 as an absorbing layer. The modifications were made by considering layers of perovskite without defects. The results show that the efficiency of the power conversion can be improved by adjusting layer thickness; in our case power conversion efficiency was increased from 9.96 % to 12.9 %.Item Economic Evaluation Analysis of Nano-silica Ultrafiltration Membrane Production from Sand(جامعة الوادي - university of el oued, 2018-06-20) Kurnia, Asep Bayu Dani Nandiyanto Asep Bayu Dani Nandiyanto; Riska, Ismiati.AinnayaIsmiati.Ainnaya; Ainnaya, AnnisaAnnisa; Fiona, Finandia Finandia; Nissa, Noor NazmiNoor Nazmi Aulia; Dewi, Rita ChintiaThe purpose of this research was to analyze the production method of a membrane of silica nanoparticles from an economic perspective. Silica nanoparticles are synthesized using a coprecipitation method. Briefly, the process consists of immersion, heating, precipitation, washing and drying, and packaging. The parameters used for economic analysis are gross profit margin (GPM), internal rate return (IRR), payback period (PBP), cumulative net present value (CNPV), break-even point (BEP), and profitability index (PI). The production of this ultrafiltration nano-silica membrane can be done by varying the amount of initial sand from 6 to 14 kg. The production of ultrafiltration nano-silica membranes can be produced in both domestic and micro-scale industries. To get a very good profit, economic analysis shows the minimum amount of sand used should be more than six kg. This study is very important because the production of ultrafiltration nano-silica membranes have a high potential in the field of economics and will encourage further investigation for the possibility of industrial production of these ultrafiltration nano silica membranes.Item Control with Sliding Mode of a Five-Phase Series-Connected Two-asynchronous Motor Drive(جامعة الوادي - university of el oued, 2018-06-28) zouaid, zouaid; i nezli, LazhariIn this paper, we study sliding mode control of series-connected five-phase two asynchronous machines supplied with a three levels inverter. After presentation of multiphase machines, we worked out the mathematical model of five phase asynchronous machine supplied with voltage inverter. Application of Park transformation reduces considerably the mathematical model of machine. After, we applied vector control and sliding mode control to the five-phase induction machine. After that, we study a multi-machine system, which comport five-phase two asynchronous machines supplied with a single voltage inverter. In the last, we had the sliding mode control of series-connected five-phase two asynchronous machines. Simulations are presented to show the effectiveness of the control strategy. We observe that an appropriate transposition of phase’s order permits an independent control of two machines.