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51.
Mohamed Ammar Abbassi Najla Grioui Kamel Halouani Andr Zoulalian Belkacem Zeghmati 《Fuel Processing Technology》2009,90(10):1278-1285
A pilot plant of biomass pyrolysis using pyrolysis products as fuel has been tested and shown to improve energy balance of the process and to be environmentally friendly by avoiding rejection of pyrolysis pollutants fumes into the atmosphere. The high number of parameters involved in a pyrolysis process makes it difficult to specify an optimum procedure for charcoal yield and pyrolysis cycle durability. So the knowledge of the essential parameters which govern the kinetics mechanisms of the biomass thermal decomposition and the combustion of pyrolysis gases is very useful to understand the operating cycle of the plant. In the present study a thermochemical model is developed in order to simulate and control the operating cycle of the system. The effect of the inlet molar air flow rate on the temporal evolution of biomass mass loss rate and temperatures in the different active zones of the pilot plant as well as the determination of the critical inlet molar air flow rate for which accidental runaway of combustion reactions occurs are presented. To avoid this accidental phenomenon a Proportional-Integral-Derived (PID) anticipated regulation is used in order to control temperatures evolution in the different zones of the device and avoid the runaway of combustion reactions. 相似文献
52.
Mohamed Kamel Hadj-Kali Vincent Gerbaud Patrick Lovera Olivier Baudouin Pascal Floquet Xavier Joulia Jean-Marc Borgard Philippe Carles 《International Journal of Hydrogen Energy》2009
A model for the Bunsen section of the Sulfur–Iodine thermo-chemical cycle is proposed, where sulfur dioxide reacts with excess water and iodine to produce two demixing liquid aqueous phases (H2SO4 rich and HI rich) in equilibrium. Considering the mild temperature and pressure conditions, the UNIQUAC activity coefficient model combined with Engels' solvation model is used. The complete model is discussed, with HI solvation by water and by iodine as well as H2SO4 solvation by water, leading to a very high complexity with almost hundred parameters to be estimated from experimental data. Taking into account the water excess, a successful reduced model with only 15 parameters is proposed after defining new apparent species. Acids total dissociation and total H+ solvation by water are the main assumptions. Results show a good agreement with published experimental data between 25 °C and 120 °C. 相似文献
53.
A novel multi-model neuro-fuzzy-based MPPT for three-phase grid-connected photovoltaic system 总被引:1,自引:0,他引:1
This paper presents a novel methodology for Maximum Power Point Tracking (MPPT) of a grid-connected 20 kW photovoltaic (PV) system using neuro-fuzzy network. The proposed method predicts the reference PV voltage guarantying optimal power transfer between the PV generator and the main utility grid. The neuro-fuzzy network is composed of a fuzzy rule-based classifier and three multi-layered feed forwarded Artificial Neural Networks (ANN). Inputs of the network (irradiance and temperature) are classified before they are fed into the appropriated ANN for either training or estimation process while the output is the reference voltage. The main advantage of the proposed methodology, comparing to a conventional single neural network-based approach, is the distinct generalization ability regarding to the nonlinear and dynamic behavior of a PV generator. In fact, the neuro-fuzzy network is a neural network based multi-model machine learning that defines a set of local models emulating the complex and nonlinear behavior of a PV generator under a wide range of operating conditions. Simulation results under several rapid irradiance variations proved that the proposed MPPT method fulfilled the highest efficiency comparing to a conventional single neural network and the Perturb and Observe (P&O) algorithm dispositive. 相似文献
54.
55.
Adams Kong Author Vitae David Zhang Author Vitae Mohamed Kamel Author Vitae 《Pattern recognition》2006,39(3):478-487
In this paper, we propose a feature-level fusion approach for improving the efficiency of palmprint identification. Multiple elliptical Gabor filters with different orientations are employed to extract the phase information on a palmprint image, which is then merged according to a fusion rule to produce a single feature called the Fusion Code. The similarity of two Fusion Codes is measured by their normalized hamming distance. A dynamic threshold is used for the final decisions. A database containing 9599 palmprint images from 488 different palms is used to validate the performance of the proposed method. Comparing our previous non-fusion approach and the proposed method, improvement in verification and identification are ensured. 相似文献
56.
The effects of mobile-phase additives and analyte concentration on electrospray ionization mass spectra of a series of tetracyclines were investigated in both positive and negative ion modes. Only [M + H](+) and [M - H](-) ions were observed. The greatest sensitivity as [M + H](+) ions was obtained with 1% acetic acid and the greatest sensitivity as [M - H](-) ions was obtained using 50 mM ammonium hydroxide. Sensitivities in the positive ion mode were greater than those in the negative ion mode. The sensitivity as [M + H](+) showed no systematic variation with pH; however, the sensitivity as [M - H](-) did increase with increasing pH. A larger linear range was observed for [M - H](-) than for [M + H](+) ions. Both [M + Na](+) and [M + H](+) ions were observed with 0.5 mM sodium acetate and sodium iodide, but no adduct ions were observed with ammonium acetate. Some M(2)H(+) ions were observed at higher concentrations. Cluster ions, Na(NaOAc)(n)(+) or Na(NaI)(n)(+), but no sample ions were observed using 5 mM salts. The data suggest that mechanisms in addition to solution ionization are involved in the formation of the ESI sample ions. The utility of mobile phases containing 1% HOAc or 50 mM NH(4)OH was demonstrated for chromatographic separations. 相似文献
57.
Both specific polycolonal antibody and monoclonal antibody against the microsomal antigen of adult S. mansoni were used to detect antigenaemia and antigenuria by antigen-capture sandwich ELISA in the sera and urine of patients infected with S. mansoni and other parasites. Antigenaemia was detected in 22 sera out of 100 of patients infected with S. mansoni but no antigenuria was detected. None of the sera of S. mansoni free patients were positive for microsomal antigen. More standardization of the technique and more refining of the reagents used is required to improve the sensitivity of the test. 相似文献
58.
Abdel-Aziz H. Kamel 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1973,23(7):489-492
The strength of dense high-slag cement-sand mixes autoclaved at 180 lbf/in2, and of certain aerated mixes autoclaved at pressures ranging from 120 to 210 lbf/in2, has been determined. It was found that maximum strengths were developed in an autoclaving period of 5 h at 180 lbf/in2, and that longer periods, as well as higher autoclaving pressures, yielded lower strengths. The maximum strength values obtained for compacted 1: 3 (w/w) mixes were 425 kg/cm2 in the absence of fine quartz, and 510 kg/cm2 in the presence of suitable addition of fine quartz. The corresponding values for Portland cement mixes were, respectively, 330 and 460 kg/cm2 for a heating period of 5 h, and 360 and 505 kg/cm2 for a period of 6 h. 相似文献
59.
The anodic oxidation of manganese-zinc amalgams of different concentrations was studied in 0·1, 1·0, 2·0 and 4·0N NaOH solutions at 25°C. The polarization curves obtained under constant currents exhibited several steps corresponding to the formation of Zn(OH)2, Mn(OH)2, MnO3 and oxidation of mercury before O2 evolution took place. The effect of presence of zinc on the oxidation step of manganese is explained. 相似文献
60.
The response of a two-degree-of-freedom system with quadratic coupling under a modulated amplitude sinusoidal excitation is studied and solved. The method of multiple scale perturbation technique is applied to obtain the bifurcation response equation near the combination resonance case in the presence of internal resonance of this system. The main attention is focused on the stability of the periodic solution and dynamical properties of local bifurcations of this system. The numerical solution and the effects of some parameters on the vibrating system are investigated and reported in this paper. 相似文献