Degré d’impact des aménagements hydrauliques sur le ruissellement et le transport solide dans une région semi aride : cas des micro-bassins dans le haut Isser, Algérie

L’érosion est un ensemble de processus variables dans le temps et dans l'espace. La variation se fait en fonction des conditions écologiques et des mauvaises conditions de gestion de la terre par l'homme. C’est pourquoi la lutte antiérosive intéresse divers acteurs dont les intérêts ne sont pas forcément compatibles. Ses effets sont conséquents sur les ressources en eau par la réduction de la capacité de stockage des barrages et la mauvaise qualité de l’eau, d’une part, et sur le sol par la perte de sa fertilité, d’autre part. En Algérie septentrionale, ce phénomène est crucial. De nombreux chercheurs se sont penchés pour traiter ce problème ; que ce soit dans l’aspect de quantification que dans celui de la lutte anti-érosive. Nous avons tenté d’approcher le phénomène dans ces deux aspects, en prenant comme zone d’étude les micro-bassins 'expérimentaux de Beni Slimane, dans le bassin versant de lOued Isser. L’intensité de l’érosion hydrique sur ce bassin versant s’explique par la prédominance des terrains marneux, des ruissellements concentrés et un couvert végétal quasi inexistant. L’impact des aménagements  hydrauliques sur le ruissellement a été démontré sur les micros bassins expérimentaux. C’est dans cette optique que s’inscrit l’objectif de ce travail, vu l’importance que revêt la région par rapport à son alimentation en eau potable de la capitale, d’une part, et à une agriculture florissante, d’autre part.Mots-clés : capacité de stockage, érosion, ruissellement, impact, micros bassins expérimentau

Interconnection performance analysis of single phase neural network based NPC and CHB multilevel inverters for grid-connected PV systems

This paper presents the interconnection performance analysis of single-phase cascaded H-bridge and neutral point clamped multilevel inverters for grid-connected photovoltaic (PV) applications. Interconnection performance analysis of both inverters was investigated using fixed and variable bands hysteresis current control strategies to ensure a lower current's total harmonic distortion (THD). An intelligent control method based on neural networks was introduced to extract maximum power from the PV modules and to achieve optimal operation of the whole system when connected to the utility grid. Control algorithm was implemented in a microcontroller with interrupt routines priority. Both simulation and experimental results are presented to verify the performance of the proposed control methods. In addition, islanding detection capability of the two topologies was investigated. © 2019 International Journal of Renewable Energy Research

Clinical spectrum of MTOR-related hypomelanosis of Ito with neurodevelopmental abnormalities

PURPOSE: Hypomelanosis of Ito (HI) is a skin marker of somatic mosaicism. Mosaic MTOR pathogenic variants have been reported in HI with brain overgrowth. We sought to delineate further the pigmentary skin phenotype and clinical spectrum of neurodevelopmental manifestations of MTOR-related HI. METHODS: From two cohorts totaling 71 patients with pigmentary mosaicism, we identified 14 patients with Blaschko-linear and one with flag-like pigmentation abnormalities, psychomotor impairment or seizures, and a postzygotic MTOR variant in skin. Patient records, including brain magnetic resonance image (MRI) were reviewed. Immunostaining (n = 3) for melanocyte markers and ultrastructural studies (n = 2) were performed on skin biopsies. RESULTS: MTOR variants were present in skin, but absent from blood in half of cases. In a patient (p.[Glu2419Lys] variant), phosphorylation of p70S6K was constitutively increased. In hypopigmented skin of two patients, we found a decrease in stage 4 melanosomes in melanocytes and keratinocytes. Most patients (80%) had macrocephaly or (hemi)megalencephaly on MRI. CONCLUSION: MTOR-related HI is a recognizable neurocutaneous phenotype of patterned dyspigmentation, epilepsy, intellectual deficiency, and brain overgrowth, and a distinct subtype of hypomelanosis related to somatic mosaicism. Hypopigmentation may be due to a defect in melanogenesis, through mTORC1 activation, similar to hypochromic patches in tuberous sclerosis complex

Clinical spectrum of MTOR-related hypomelanosis of Ito with neurodevelopmental abnormalities.

PURPOSE: Hypomelanosis of Ito (HI) is a skin marker of somatic mosaicism. Mosaic MTOR pathogenic variants have been reported in HI with brain overgrowth. We sought to delineate further the pigmentary skin phenotype and clinical spectrum of neurodevelopmental manifestations of MTOR-related HI. METHODS: From two cohorts totaling 71 patients with pigmentary mosaicism, we identified 14 patients with Blaschko-linear and one with flag-like pigmentation abnormalities, psychomotor impairment or seizures, and a postzygotic MTOR variant in skin. Patient records, including brain magnetic resonance image (MRI) were reviewed. Immunostaining (n = 3) for melanocyte markers and ultrastructural studies (n = 2) were performed on skin biopsies. RESULTS: MTOR variants were present in skin, but absent from blood in half of cases. In a patient (p.[Glu2419Lys] variant), phosphorylation of p70S6K was constitutively increased. In hypopigmented skin of two patients, we found a decrease in stage 4 melanosomes in melanocytes and keratinocytes. Most patients (80%) had macrocephaly or (hemi)megalencephaly on MRI. CONCLUSION: MTOR-related HI is a recognizable neurocutaneous phenotype of patterned dyspigmentation, epilepsy, intellectual deficiency, and brain overgrowth, and a distinct subtype of hypomelanosis related to somatic mosaicism. Hypopigmentation may be due to a defect in melanogenesis, through mTORC1 activation, similar to hypochromic patches in tuberous sclerosis complex

Field test of the bulk-assay calorimeter

The Bulk-Assay Calorimeter described in ANL-NDA-9/ISPO-14 was field tested at the Belgonucleaire mixed-oxide fuel fabrication plant at Dessel, Belgium, May 13-19, 1982. This instrument was developed under ISPO Tasks A-9 and A-47 at Argonne National Laboratory and was supplied to the IAEA through the U.S support program. Five containers of plutonium-oxide feed stock used in the manufacture of mixed-oxide LMFBR-type fuel were assayed during the test. Electrical measurements to verify the calibration of the calorimeter were also made

Field test and evaluation of the passive neutron coincidence collar for prototype fast reactor fuel subassemblies

The passive neutron Coincidence Collar, which was developed for the verification of plutonium content in fast reactor fuel subassemblies, has been field tested using Prototype Fast Reactor fuel. For passive applications, the system measures the /sup 240/Pu-effective mass from the spontaneous fission rate, and in addition, a self-interrogation technique is used to determine the fissile content in the subassembly. Both the passive and active modes were evaluated at the Windscale Works in the United Kingdom. The results of the tests gave a standard deviation 0.75% for the passive count and 3 to 7% for the active measurement for a 1000-s counting time. The unit will be used in the future for the verification of plutonium in fresh fuel assemblies

Field test and evaluation of the IAEA coincidence collar for the measurement of unirradiated BWR fuel assemblies

The neutron coincidence counter has been field tested and evaluated for the measurement of boiling-water-reactor (BWR) fuel assemblies at the ASEA-ATOM Fuel Fabrication Facility. The system measures the /sup 235/U content per unit length of full fuel assemblies using neutron interrogation and coincidence counting. The /sup 238/U content is measured in the passive mode without the AmLi neutron interrogatioin source. The field tests included both standard production movable fuel rods to investigate enrichment and absorber variations. Results gave a response standard deviation of 0.9% for the active case and 2.1% for the passive case in 1000-s measurement times. 10 figures, 2 tables

Modeling of discharge and sediment transport through the SWAT model in the basin of Harraza Northwest of Algeria)

The objective of this study is to model discharge and solid erosion quantification through a small agricultural watershed by applying the SWAT model (Soil and Water Assessment Tools) on the Wadi Harraza's basin of which is part of Wadi Cheliff's basin, with an average altitude of 500 m, drains an area of 568 sq km. Soil and Water Assessment Tool (SWAT, version 2009) model integrated with Geographic Information System (ArcGIS, version 10.0) were used to simulate the discharge and sediment concentration of Wadi Harraza's basin for the period from 2004 to 2009. Model calibration and validation were performed for monthly time periods using Sequential Uncertainty Fitting 2 (SUFI-2, version 2) within SWAT-CUP. Our calibration and validation outputs for monthly simulation showed a good model performance for discharges. Thus the evolution of the average total annual sediment in the Wadi Harraza's basin which will be deposited in the Wadi Cheliff, is estimated at 54.24 t ha-1

Efficient extraction of hydrophilic and lipophilic antioxidants from microalgae with supramolecular solvents

There is strong evidence that lipophilic and hydrophilic antioxidants interact in vivo through different mechanisms and that it is their mixed effects what leads to health benefits. Simultaneous extraction of both types of antioxidants from biomass using organic solvents is inefficient because extraction yields for these phytochemicals are highly dependent on the polarity of the solvent. In this work, we firstly propose the use of supramolecular solvents (SUPRAS) as an innovative approach for the simultaneous extraction of a wide polarity range of antioxidants. Different SUPRAS compositions were investigated for extraction of the total content of carotenoids and polyphenols, as representatives of lipophilic and hydrophilic antioxidants, respectively. Under optimal conditions, antioxidants were extracted from freeze-dried biomass of Scenedesmus sp. in an excellent rate related to their total content (up to 1 mg carotenoids/g dw and 10 mg of gallic acid equivalents, GAE/g dw). Screening based on liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) revealed that lutein was the major carotenoid and caffeic acid the main phenolic compound. The SUPRAS extracts showed high antioxidant activity (25.04 ± 0.73 µM ascorbic acid equivalents antioxidant capacity, AAAC/g dw and 17.02 ± 0.45 µM AAAE/g dw for ABTS and DPPH assays, respectively). SUPRAS offered advantages in terms of non-toxicity, rapidity (5 min extraction) and cost-effectiveness (room temperature, atmospheric pressure) for the recovery of antioxidant compounds from algal biomass and constitute a good alternative to the use of conventional solvents