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. 

Extractive Text-Based Summarization of Arabic videos: Issues, Approaches and Evaluations

International audienceIn this paper, we present and evaluate a method for extractive text-based summarization of Arabic videos. The algorithm is proposed in the scope of the AMIS project that aims at helping a user to understand videos given in a foreign language (Arabic). For that, the project proposes several strategies to translate and summarize the videos. One of them consists in transcribing the Ara-bic videos, summarizing the transcriptions, and translating the summary. In this paper we describe the video corpus that was collected from YouTube and present and evaluate the transcription-summarization part of this strategy. Moreover, we present the Automatic Speech Recognition (ASR) system used to transcribe the videos, and show how we adapted this system to the Algerian dialect. Then, we describe how we automatically segment into sentences the sequence of words provided by the ASR system, and how we summarize the obtained sequence of sentences. We evaluate objectively and subjectively our approach. Results show that the ASR system performs well in terms of Word Error Rate on MSA, but needs to be adapted for dealing with Algerian dialect data. The subjective evaluation shows the same behaviour than ASR: transcriptions for videos containing dialectal data were better scored than videos containing only MSA data. However, summaries based on transcriptions are not as well rated, even when transcriptions are better rated. Last, the study shows that features, such as the lengths of transcriptions and summaries, and the subjective score of transcriptions, explain only 31% of the subjective score of summaries

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

Characteristics of the deflection of a liquid jet in an annular flow

SIGLEAvailable from British Library Document Supply Centre-DSC:8019.322(no 92814) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

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

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