Radioactivity Distribution In Surface And Core Sediment Of The Central Part Of The Algerian Coast: An Estimation Of The Recent Sedimentation Rate

Sediment core samples and marine surface sediments of identical composition, mostly muddy, were collected using a Van Veen type grab and a box corer on board the M.S. Benyahia research vessel (ISMAL), along the Algerian littoral, between Algiers (36Ζ49.9 N/ 03Ζ 02.3 E) and Cherchell (36Ζ 39.4 N/ 02Ζ 12.4 E), during a sampling cruise in September 1997. The samples were analysed to determine the activity concentration of natural radionuclides (uranium and thorium series and 40 K as well) and artificial radionuclides ( 137 Cs and Pu isotopes), using a direct gamma spectrometry for gamma emitters and radiochemical separations and alpha spectrometry for alpha emitters. The horizontal and vertical distribution of the examined radionuclides were studied in the surface and core samples and an effort to estimate the sedimentation rate was attempted.The measured values range was: 17 - 26 Bq/Kg dry for uranium series radioisotopes, 18 – 32 Bq/Kg dry for thorium series radioisotopes, 311 - 690 Bq/Kg dry for 40 K, 0.4 - 11 Bq/Kg dry, for 137 Cs and 0.4 – 1.0 Bq/Kg dry for 239 + 240 Pu

DIAGNOSTIC DES DEFAUTS DANS LES MOTEURS ASYNCHRONES TRIPHASES A CAGE Partie I : Modèle Dédié à la Simulation des Ruptures de Barres

Dans cet article nous présenterons un modèle mathématique dédié à la simulation des ruptures de barres dans un moteurasynchrone triphasé à cage. Ce modèle est basé sur un circuit maillé représentant la cage rotorique. Des testes de simulationnous ont permis de montrer l'efficacité de ce modèle pour décrire le comportement de la machine dans l'état sain et avec défaut

DIAGNOSTIC DES DEFAUTS DANS LES MOTEURS ASYNCHRONES TRIPHASES A CAGE Partie II : Méthodes dédies a la détection des cassures de barres dans les moteurs asynchrones triphasés a cage

Dans cet article, nous allons présenter trois méthodes dédiées à la détection des cassures de barres dans un moteur asynchronetriphasé à cage. Ces méthodes sont basées sur l'analyse spectrale (par FFT) des signaux du couple, de la vitesse et du courantstatorique afin de déterminer leurs composition fréquentielle, et donc de retrouver les raies associées au défaut. Ce travail est lacontinuité naturelle de celui de la partie I, dans laquelle on a présenté un modèle multi-enroulement décrivant le comportementdu moteur en présence de cassure de barres. Une étude analytique du défaut est décrite. Les résultats de la simulation obtenusnous ont permis de montrer l'intérêt de ces techniques ainsi que la comparaison entres elles. 

Dispersion field analysis using discrete wavelet transform for inter-turn stator fault detection in induction motors

International audienceThis paper presents an inter-turn shortcircuit detection through the measurement of externalmagnetic field of induction motor. The technique ofanalysis is based on discrete wavelet transform energy intransient state where the machine operates at start-upand standstill states. The wavelet offers a very fineanalysis of the unidimensional and two-dimensionalsignals. Through multilevel discrete waveletdecomposition, it is possible to extract the informationfor the prognosis of the fault in variable state of themachine. The stored energy calculation in eachdecomposition can evaluate the severity of the faultcompared with the analysis of only the externalmagnetic field

Distribution of Natural Radioactivity, 137Cs, 90Sr, and Plutonium Isotopes in a Water Column and Sediment Core along the Algerian Coast

Concentrations of natural (40K, 210Pb, uranium, and thorium series) and artificial radioelements (137Cs, 90Sr, 239+240Pu) were determined in seawater and sediment samples collected from stations along the Algerian coast. Seawater was collected from the surface to a maximum depth of 2000 m; the sediment cores were sampled from a depth of around 1500 m. This work was carried out in August 2001, in the framework of the Regional African project /7/004 (RAF), by the accomplishment of an oceanographic campaign organized by the International Atomic Energy Agency (IAEA) in collaboration with Commissariat à l'Energie Atomique (COMENA) and L'Institut des Sciences de la Mer et de L'Amenagement du Littoral (ISMAL), on board of the research vessel of M.S. Benyahia of ISMAL. In addition to the record of the conductivity (mS) and temperature (°C) data at each station, seawater samples were treated and preconcentrated on board, those of sediment cores were divided into different layers in order to undergo analyses in the laboratory of radiological impact studies of Algiers. Concentration results were obtained for 137Cs and 90Sr in mBq/L and 239+240Pu in μBq/L in seawater, and also for natural and artificial radionuclides in Bq/kg dry weight in the layers of the sediment cores. The different profiles of 137Cs, 239+240Pu, 90Sr, and 210Pb concentrations against depth were presented to show artificial radioactivity distribution in the water column and sediment core. Concentrations of 137Cs in the sediment core were also used to identify the 137Cs peak in the area of interest

Broken Rotor Bars Fault Detection in Induction Motors Using FFT: Simulation and Experimentally Study

This paper presents the fault detection of broken rotor bars based on the analysis technique, such as the Fast Fourier transform (FFT), which utilize the steady-state spectral components of the stator quantities is considered. This technique has been given expected results, the accuracy of this technique depends on the loading conditions and constant speed of the motor. This method shows good theoretical and experimental results. Cite as: Kechida, R., Menacer, A., Cherif, H. (2019). Broken Rotor Bars Fault Detection in Induction Motors using FFT: Simula-tion and Experimentally Study. Algerian Journal of Engineering and Technology, 1(1), 019-024.  https://doi.org/10.5281/zenodo.3595143 References Ayhan, B. Trussell, H.J. Chow, Mo-Yuen. Song, Myung-Hyun (2008). On the use of a lower sampling rate for broke rotor bar detection with DTFT and AR-based spectrum methods. IEEE Trans. Industrial Electronics, 55(3), 1421-1434. Bachir, S. Tnani, S Trigeassou. J-C. and Champenois, G. (2006). Diagnosis by parameter estimation of stator and rotor faults occurring in induction machines. IEEE Transitions Industrial Electronics, 53(3), 963–973. Bellini, A. Filippetti, F. Tassoni, C. and Capolino. G.A. (2008). Advances in diagnostic techniques for induction machines. IEEE Transactions on Industrial Electronics, 55(12), 4109-4125. Silva, A.M.D. Povinelli, R. J. and Demerdash, N. A. O. (2008). Induction machine broken bar and stator short-circuit fault diagnostics based on three-phase stator current envelopes. IEEE Transactions on Industrial Electronics, 55(3), 1310–1318. Bossio, G. R. De Angelo, C. Bossio, H. J. M. Pezzani, C. M. and García, G.O.(2009). Separating broken rotor bars and load oscillations on im fault diagnosis through the instantaneous active and reactive currents. IEEE Transactions on Industrial Electronics, 56(11), 4571–4580. Bouzida, A. Touhami, O. Ibtiouen, R. Belouchrani, A. Fadel, M. and Rezzoug, A. (2011). Fault Diagnosis in industrial induction Machines through Discrete Wavelet Transform. IEEE Transactions Industrial Electronics, 58(9), 4385–4395. Sadeghian, A. Ye, Z. and Wu, B. (2009). Online detection of broken rotor bars in induction motors by wavelet packet decomposition and artificial neural networks. IEEE Transactions Instrumentation and Measurement, 58(7), 2253-2263. Cusidó, J. Romeral, L. Ortega, J. A. Rosero, J. A. Garcia Espinosa, A. (2008). Fault detection in induction machines using power spectral density in wavelet decomposition. IEEE Trans. Industrial Electronics, 55(3), 633-643. Zhou, W. Habetler, T. G. and Harley, R.G. (2007). Stator current based bearing fault detection techniques: A general review, IEEE International Symposium on Diagnostics for Electric Machines, Power Electronics and Drives, pp. 7-10. Blodt, M. Granjon, P. Raison, B. Rostaing, G. (2008). Models for bearing damage detection in induction motors using stator current monitoring. IEEE Transactions on Industrial Electronics, 55(4), 1813-1822. Douglas, H. Pillay, P and Ziarani, A. K. (2005). Broken rotor bar detection in induction machines with transient operating speeds. IEEE Transactions on Energy Conversion, 20(1), 135-141. Antonio-Daviu, J.A. Riera-Guasp, M. Floch, J. R. Palomares, M.P.M. (2006). Validation of a new method for the diagnosis of rotor bar failures via wavelet transform in industrial induction machines. IEEE Transactions on Industry Applications, 42(4), 990–996. Ordaz-Moreno, A. Romero-Troncoso, R.J. Vite-Frias, J.A. Rivera-Gillen, J.R. Garcia-Perez, A. (2008). Automatic online diagnosis algorithm for broken-bar detection on induction motors based on discrete wavelet transform for FPGA implementation. IEEE Transactions on Industrial Electronics, 55(5), 2193-2202. Cusido, J. Rosero, J. Aldabas, E. Ortega, L. Romeral, J.A. (2006). New fault detection techniques for induction motors. Electrical Power Utilization Quality and, Magazine, 11(1), 39-45. Caruso, G. Iannuzzi, D. Maceri, F. Pagano, E. Piegari, L. (2008). Torsional eigenfrequency identification of squirrel cage rotors of induction motors. International Symposium on Power Electronics, Electrical Drives, Automation and Motion, 1271–1275. Benbouzid, M.E.H. (2000). A review of induction motors signature analysis as a medium for faults detection. IEEE Trans Indus Elect, 47(5), 984–993. Li, W. (2006). Detection of induction motor faults: A comparison of stator current, vibration and acoustic methods. Journal of Vibration and Control. 12(2). 165

Evaluation Of The Radiological Situation In Algeria After The Algeciras Incident

The present study has been carried out in the framework of our environmental monitoring programme and immediately after being informed by the IAEA of possible accidental releases of 137 Cs into the air, which might have been released between May 25 th and the first of June 1998 from the Acerinox factory in Algeciras (Spain). Algericas is the region where a steel-processing factory has been set up. During the work procedure, a radioactive source of 137 Cs passed through the furnace resulting in accidental releases into the atmosphere. This radioactive contamination was detected in France, Switzerland, Italy and Germany, and some radioactivity measurements were carried out by the Commissariat A l'Energie Atomique to evaluate the gamma radiation status in areas selected in Algeria. The approach adopted in our case was to start in situ gamma-radiation measurements and to collect air and soil samples as well from a selected area in Algiers. Afterwards, and in order to have more reliable results, a sampling program was carried out in July 1998, in the frame of which some sampling stations were established in the west of Algeria, based upon Algerian meteorological data during the period of incident. A total number of 16 environmental samples from 9 stations, namely, soil, sediment, vegetation and seawater were collected, followed by in situ gamma radiation measurements in each sampling location. Soil, sediment and vegetation samples were analysed by direct gamma spectrometry, whereas, sea water samples were analysed radiochemically using microcrystalline AMP for coprecipitation and gamma counted. Taking into consideration the background levels of radioactivity in the studied areas, obtained by our previous monitoring programs, the results obtained do not show any increase of 137 Cs resulting from the incinerated Caesium source in the Acerinox steel factory in Algeciras, Spain. The conclusion drawn by this work is that the investigated area was not affected by the release of 137 Cs

Sensorless speed estimation and backstepping control of induction motor drive using model reference adaptive system

This paper presents a sensorless nonlinear control for an induction motor drive. The strategy is based on backstepping control in order to ensure a high-performance control and a good dynamic in different uncertainties and external disturbance. Moreover, a model reference adaptive system (MRAS) is used for rotor speed and rotor flux estimations; investigate a sensorless control algorithm by decreasing the cost of the speed sensor. The performances of the sensorless control strategy will be examined via numerical simulation and validated through Hardware implementation using Matlab/Simulink with dSpace 1104 signal card. The results analysis shows the robustness of the sensorless control algorithm for the load disturbances, the speed variation and low-speed

Behaviour of a laminar liquid jet in an annular rotating flow

Paper presented at the 9th International Symposium on Flow Visualization, Heriot-Watt University, Edinburgh, 2000SIGLEAvailable from British Library Document Supply Centre-DSC:8019.322(92822) / BLDSC - British Library Document Supply CentreGBUnited Kingdo