Center National Of Lenergie Des Science Et Des Techniques Nucleaires

Rabat, Morocco

Center National Of Lenergie Des Science Et Des Techniques Nucleaires

Rabat, Morocco
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Dercon G.,International Atomic Energy Agency | Mabit L.,International Atomic Energy Agency | Hancock G.,CSIRO | Nguyen M.L.,International Atomic Energy Agency | And 21 more authors.
Journal of Environmental Radioactivity | Year: 2012

This paper summarizes key findings and identifies the main lessons learnt from a 5-year (2002-2008) coordinated research project (CRP) on "Assessing the effectiveness of soil conservation measures for sustainable watershed management and crop production using fallout radionuclides" (D1.50.08), organized and funded by the International Atomic Energy Agency through the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture. The project brought together nineteen participants, from Australia, Austria, Brazil, Canada, Chile, China, Japan, Morocco, Pakistan, Poland, Romania, Russian Federation, Turkey, United Kingdom, United States of America and Vietnam, involved in the use of nuclear techniques and, more particularly, fallout radionuclides (FRN) to assess the relative impacts of different soil conservation measures on soil erosion and land productivity. The overall objective of the CRP was to develop improved land use and management strategies for sustainable watershed management through effective soil erosion control practices, by the use of 137Cs (half-life of 30.2 years), 210Pb ex (half-life of 22.3 years) and 7Be (half-life of 53.4 days) for measuring soil erosion over several spatial and temporal scales. The environmental conditions under which the different research teams applied the tools based on the use of fallout radionuclides varied considerably - a variety of climates, soils, topographies and land uses. Nevertheless, the achievements of the CRP, as reflected in this overview paper, demonstrate that fallout radionuclide-based techniques are powerful tools to assess soil erosion/deposition at several spatial and temporal scales in a wide range of environments, and offer potential to monitor soil quality. The success of the CRP has stimulated an interest in many IAEA Member States in the use of these methodologies to identify factors and practices that can enhance sustainable agriculture and minimize land degradation. © 2012 Elsevier Ltd.

Auguy F.,CIRAD - Agricultural Research for Development | Fahr M.,Center National Of Lenergie Des Science Et Des Techniques Nucleaires | Moulin P.,Mohammed V University | El Mzibri M.,Center National Of Lenergie Des Science Et Des Techniques Nucleaires | And 4 more authors.
Frontiers in Plant Science | Year: 2016

Hirschfeldia incana, a pseudometallophyte belonging to the Brassicaceae family and widespread in the Mediterranean region, was selected for its ability to grow on soils contaminated by lead (Pb). The global comparison of gene expression using microarrays between a plant susceptible to Pb (Arabidopsis thaliana) and a Pb tolerant plant (H. incana) enabled the identification of a set of specific genes expressed in response to lead exposure. Three groups of genes were particularly over-represented by the Pb exposure in the biological processes categorized as photosynthesis, cell wall, and metal handling. Each of these gene groups was shown to be directly involved in tolerance or in protection mechanisms to the phytotoxicity associated with Pb. Among these genes, we demonstrated that MT2b, a metallothionein gene, was involved in lead accumulation, confirming the important role of metallothioneins in the accumulation and the distribution of Pb in leaves. On the other hand, several genes involved in biosynthesis of ABA were shown to be up-regulated in the roots and shoots of H. incana treated with Pb, suggesting that ABA-mediated signaling is a possible mechanism in response to Pb treatment in H. incana. This latest finding is an important research direction for future studies. © 2016 Auguy, Fahr, Moulin, El Mzibri, Smouni, Filali-Maltouf, Béna and Doumas.

Laamara R.A.,Ufr Laboratory Of Physique Des Hautes Energies And Groupement National Of Phe Gnphe | Belhaj A.,Ufr Laboratory Of Physique Des Hautes Energies And Groupement National Of Phe Gnphe | Belhaj A.,Center National Of Lenergie Des Science Et Des Techniques Nucleaires | Boya L.J.,University of Zaragoza | And 2 more authors.
International Journal of Geometric Methods in Modern Physics | Year: 2010

We discuss quiver gauge models with bi-fundamental and fundamental matter obtained from F-theory compactified on ALE spaces over a four-dimensional base space. We focus on the base geometry which consists of intersecting F 0 = CP1 × CP1 Hirzebruch complex surfaces arranged as Dynkin graphs classified by three kinds of KacMoody (KM) algebras: ordinary, i.e. finite-dimensional, affine and indefinite, in particular hyperbolic. We interpret the equations defining these three classes of generalized Lie algebras as the anomaly cancelation condition of the corresponding N = 1 F-theory quivers in four dimensions. We analyze in some detail hyperbolic geometries obtained from the affine  base geometry by adding a node, and we find that it can be used to incorporate fundamental fields to a product of SU-type gauge groups and fields. © 2010 World Scientific Publishing Company.

Aouade G.,Cadi Ayyad University | Ezzahar J.,Cadi | Amenzou N.,Center National Of Lenergie Des Science Et Des Techniques Nucleaires | Er-Raki S.,Cadi Ayyad University | And 3 more authors.
Agricultural Water Management | Year: 2016

A good knowledge of the partitioning of evapotranspiration (ET) is particularly important for improving crop water productivity, especially in semi-arid regions where irrigated agriculture uses up to 85% of total available water. In this paper, stable isotopic method and micrometeorological data were combined to assess the ET partition into plant transpiration and soil evaporation of an irrigated winter wheat field lying in the center of Morocco characterized by a semi-arid climate. Atmospheric, vegetation and soil samples were collected during two consecutive growing seasons (2011–2012 and 2012–2013). The sampling campaign was carried out after and before two irrigation events and lasted for five days. Additionally, an Eddy covariance system and a standard meteorological station were installed. Isotope turbulent mixing relationships, isotopic values of transpired water from plants (T) and that of evaporating water vapor from soil surface (E) were used to estimate fractions of transpiration and evaporation contributing to the total ET. The partition of ET was only performed by using δ2H. In fact, results obtained during 2011–2012 period, showed that this method worked well for the deuterium in comparison to oxygen-18 (δ18O). After irrigation, the ratios T/ET were about 0.73, 0.59 and 0.74 respectively in Days Of Year (DOY) 53, 54 and 55, averaging 0.69. Prior to irrigation, when the soil was dry, the T/ET ratio was 0.83 and 0.77, respectively in two days (DOY 101 and 102), averaging 0.80. Afterward, these fractions have been used in conjunction with Eddy Covariance measurements for converting the obtained percentages to mm d−1 values which are required by the farmers and the water managers. The obtained averages of evaporation and transpiration were respectively: 1.76 and 3.85 mm d−1 for the 2011–2012 and 1.34 and5.45 mm d−1for the 2012–2013. Our approach is useful for partitioning ET in an irrigated winter wheat under semi-arid climate at an ecosystem scale on short time steps. © 2016 Elsevier B.V.

Ouardi A.,Center National Of Lenergie Des Science Et Des Techniques Nucleaires | Askour A.,Hassan II University | Benchekroun D.,Hassan II University | Tamri H.,Oncology Center Al Kindy
2013 3rd International Conference on Advancements in Nuclear Instrumentation, Measurement Methods and Their Applications, ANIMMA 2013 | Year: 2013

Because it is absolutely inert in the human body, immune to attack from bodily fluids, compatible with bone growth, and strong and flexible, titanium is the most biocompatible of all metals. The purpose of this study was to investigate the dosimetric effect of various cerebral implant Titanium plate thickness ( irradiated by 4 MV photon beam using Monte Carlo (Fluka). The simulations result shows that increasing thicknesses of the Ti plate rise the dose deposition near to plate. Also the dose deposition is varying when the Ti plate is set in different depth from the surface of the water equivalent phantom (for example the dose deposition decrease about 8% for 1cm). The second part of this study is dedicate to investigate the effect of scattered radiation produced in a cerebral implant for various materials including Ti alloys such as Ti-6Al-7Nb, Ti-6Al-4V(α) and Ti-6Al-4V(β). © 2013 IEEE.

Belhaj A.,Université Ibn Tofail | Belhaj A.,Center National Of Lenergie Des Science Et Des Techniques Nucleaires | Fahssi N.-E.,Université Ibn Tofail | Saidi E.H.,Université Ibn Tofail | Segui A.,University of Zaragoza
International Journal of Geometric Methods in Modern Physics | Year: 2011

We engineer U(1)n ChernSimons type theories describing fractional quantum Hall solitons (QHS) in 1 + 2 dimensions from M-theory compactified on eight-dimensional hyper-Kähler manifolds as target space of N = 4 sigma model. Based on M-theory/type IIA duality, the systems can be modeled by considering D6-branes wrapping intersecting Hirzebruch surfaces F0's arranged as ADE Dynkin Diagrams and interacting with higher-dimensional R-R gauge fields. In the case of finite Dynkin quivers, we recover well known values of the filling factor observed experimentally including Laughlin, Haldane and Jain series. © 2011 World Scientific Publishing Company.

Naji S.,Mohammed V University | Naji S.,Ibb University | Belhaj A.,Sultan Moulay Slimane University | Labrim H.,Center National Of Lenergie Des Science Et Des Techniques Nucleaires | And 5 more authors.
Physica A: Statistical Mechanics and its Applications | Year: 2014

Motivated by spintronic device applications, we engineer a superlattice model based on periodic tri-layers consisting of spins σ=12, S=1 and q=32 residing on the sites of a square lattice, interacting with an external magnetic field. We study its phase diagrams and magnetic properties. We determine the corresponding ground state phase diagrams. Then, we show that this Ising lattice model exhibits a ferromagnetic phase F1, two ferrimagnetic phases F2, F3 and an antiferromagnetic phase F4. It is found that the magnetic behaviors depend on the moduli space controlled by the exchange interaction couplings. More precisely, the hysteresis loops have been established. © 2013 Elsevier B.V. All rights reserved.

Ben-Bolie G.H.,University of Yaounde I | Ele Abiama P.,University of Yaounde I | Ele Abiama P.,Institute of Geological and Mining Research | Owono Ateba P.,University of Yaounde I | And 2 more authors.
Radiation Protection Dosimetry | Year: 2013

In order to estimate the soil-to-plant transfer factors (TFs) of some natural radionuclides, the activity of 238U and 232Th was measured in the soil and in agricultural crop samples collected from identified high background radiation areas in the southwestern region of Cameroon. The results showed that the 238U and 232Th TFs values were in the ranges 1.031022-12.231021 kg kg-1 and 5.031022-9.731021 kg kg-1, respectively. These computed TFs values were found to be globally higher than those proposed by the International Atomic Energy Agency. © The Author 2013. Published by Oxford University Press. All rights reserved.

Ele Abiama P.,Institute of geological and Mining Research | Ele Abiama P.,University of Yaounde I | Ben-Bolie G.H.,University of Yaounde I | Amechmachi N.,Center National Of Lenergie Des Science Et Des Techniques Nucleaires | And 3 more authors.
Journal of Environmental Radioactivity | Year: 2012

Concentrations of naturally occurring radionuclides 226Ra, 228Ra and 40K were determined in five most consumed vegetables in a high-level background radiation area (HLBRA) in the southwest region of Cameroon. A total of 25 foodstuff samples collected from Akongo, Ngombas, Awanda, Bikoué and Lolodorf rural districts were analyzed by gamma spectrometry. The average activity concentration values of 226Ra, 228Ra and 40K were respectively 2.30, 1.50 and 140.40 Bq kg -1 fresh-weights. The effective dose for individual consumption of the investigated foodstuff types was calculated on an estimated annual intake of such diets in the study area. The estimated total daily effective doses from the ingestion of the investigated foodstuffs for each studied long-life natural radionuclide were respectively 0.41 μSv for 226Ra, 0.84 μSv for 228Ra and 0.71 μSv for 40K. The total annual effective dose was estimated at 0.70 mSv y -1. 228Ra (44%) and 40K (36%) were found to be the main sources for internal irradiation which is very likely due to the specific uptake of these radionuclides by the studied plants. © 2012 Elsevier Ltd.

Benkdad A.,Center National Of Lenergie Des Science Et Des Techniques Nucleaires | Laissaoui A.,Center National Of Lenergie Des Science Et Des Techniques Nucleaires | Tornero M.V.,Campus Universitario Rio San Pedro | Benmansour M.,Center National Of Lenergie Des Science Et Des Techniques Nucleaires | And 3 more authors.
Environmental Monitoring and Assessment | Year: 2011

Macroalgae species Codium sp, Bangia atropurpurea, Membranoptera alata, Plocamium cartilagineum, Dictyota dichotoma, Fucus spiralis and Stypocaulon scoparia were collected from seven stations along the north coast of Morocco. Samples were analysed to determine activities of naturally occurring radionuclides ( 210Pb, U isotopes and 40K) and concentrations of metals (Zn, Fe, Co, Cu, Ni, Mn, Pb, Cd, As and Cr) using radiometric and ICP-OES techniques, respectively. Metal concentrations were within ranges reported in the scientific literature, and concentrations of bio-essential elements were in the order Mn>Fe> Zn>Cu in all samples. Brown algae had the highest concentrations of almost all metals, and concentrations decreased in the order brown>red>green algae. With respect to radionuclides, the red alga P. cartilagineum had the highest activities of 210Pb, in most cases an order of magnitude higher than for the green alga Codium sp. 234U and 238U activities in all algae samples were in the range 0.96- 7.61 and 1.16-6.14 Bq/kg dry weight, respectively. Our analyses of radionuclide activities and metal concentrations in marine macroalgae showed large differences among taxa. These results provide insights into which algal species should be used for biomonitoring programmes. © 2011 Springer Science+Business Media B.V.

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