Analyse de la réponse sismique des barrages en béton compte tenu de l’interaction dynamique sol-structure-fluide

Concrete dams are considered as complex construction systems that play a major role in both economic and strategic character. Taking into account reservoir and foundation presence by modelling the dam-reservoir-foundation interaction phenomenon leads to a more realistic evaluation of the total system behavior. The dynamic behavior of dam-reservoir-foundation system under seismic loading using Ansys finite element code is the subject of this work. Oued Fodda concrete dam situated at Chlef, in North-West of Algeria was chosen as a case study. Parametric study was also performed for different ratios between foundation Young‘s modulus and dam Young‘s modulus Ef/Ed (which varies from 0.5 to 4). Added mass approach was used to model the fluid reservoir. The obtained results indicate that when dam Young‘s modulus and foundation Young‘s modulus are equal, the foundation soil leads to less displacements in the dam body and decreases the principal stresses as well as shear stresses

Approach to demography of ALS-resistant glebionis coronaria as influenced by management factors: tillage, allelopathic crops and herbicides

Glebionis coronaria (L.) Cass. ex Spach is one of the most serious weeds in cereal crops in Northern Tunisia. Our previous studies have confirmed the presence of resistance to ALS-inhibiting herbicides in G. coronaria, showing the evolution of cross-resistance through TS and NTS mechanisms. The purpose of this study was to evaluate the effects of (i) two tillage practices (conventional tillage and reduced tillage), (ii) three known allelopathic crops: Hordeum vulgare L. (Barley), Brassica napus L. (Rapeseed) and Triticum durum (Wheat) and (iii) herbicides belonging to different modes of action on the density, the cohort numbers and the growth of an ALS-inhibiting cross-resistant population of G. coronaria. Field experiments were conducted in two consecutive years (2017–2018 and 2018–2019) in the Fritissa-Mateur-Bizerte region. Our results revealed that barley considerably contributed to the decrease in G. coronaria’s density, cohort number, total biomass accumulation and plant height. The effect of rapeseed is likely dependent on the tillage practice and the timing of herbicide application, while G. coronaria could be successfully controlled in wheat using auxin herbicides. It is suggested that the management of resistant population of G. coronaria could be achieved by combining barely or rapeseed with right tillage practice and auxin herbicides’ application.This research was funded by the National Institute of Field Crops (INGC) and a Ph.D. grant from the Ministry of Research and Higher Education of Tunisia. The article processing charge (APC) was funded the National Institute of Field Crops (INGC). Joel Torra acknowledges support from the Spanish Ministry of Science, Innovation, and Universities (grant Ramon y Cajal RYC2018-0238

Physical and Optical Properties of Poly(3-AlkylThiophene) with a View to the Fabrication of a Highly Nonlinear Waveguide

Publisher: Bentham (ISSN: 1874-088X)International audienceIn order to take advantage of the very high nonlinear susceptibility of conjugated polymer materials, Poly(3-AlkylThiophene)s, P3AT, were synthesized in the laboratory. The physical, thermomechanical and linear optical propertiesof synthesized P3AT have been investigated and the first experimental attempts at creating nonlinear optical waveguides and determining their characteristics are presented. After synthesizing P3AT, the relationships between polymer chain characteristics and mechanical properties are investigated to see if the polymer is suitable for optical waveguide process technology. We also examine the optical attenuation of the synthesized material, a crucial factor in anticipating the relative opacity of the future component. For the first time we present the absorption spectrum of 3-Octylthiophenemolecules in the Near Infra-Red (NIR) region that suggests optical losses for the material are about 0.6 dB.cm-1 at 1550 nm. Next we examined several waveguide structures such as ridge, buried and Strip Loaded WaveGuides (SLWG) based on P3AT material. For the buried waveguides, we have observed the signal transmission and in our opinion the low optical transmission of P3AT ridge and SLWG could be attributed to extrinsic losses (mainly scattering) due to both the remaining insoluble products in the polymer and to the poor adhesion between optical layers

Effet du Prosulfocarbe sur le ray-grass (Lolium rigidum Gaud.) résistant aux herbicides inhibiteurs de l’ALS et de l’ACCase

Ryegrass (Lolium rigidum Gaud.) developed resistance to Acetolactate Synthase (ALS) and Acetyl-CoA Carboxylase (ACCase) inhibiting herbicides. The objective is to evaluate the effect of the active substance ‘Prosulfocarb’, sprayed in post-sowing preemergence at different rates and associated with S-metolachlor on ryegrass resistant to registered rate (3200 g ha-1) and according to the stages of application (SAP1: 1 day after sowing of wheat, SAP2: 7 days after sowing and SAP3: 2 to 3 leaves after emergence). The study also evaluated the effect of Prosulfocarb and post-emergence herbicides on durum wheat yield and its components. To meet these objectives, field trials were carried out in northern Tunisia (Mateur/Bizerte), with a Randomized Complete Bloc Design (RCBD). The evaluation was carried out over three successive seasons (2012/13 to 2014/15). The results revealed that the efficacy of prosulfocarb improved with increasing application rate. The S-metolachlor favored the improvement of prosulfocarb efficacy by 6 to 15%. Results also showed that the efficacy of prosulfocarb was better in the first two growth stages of the application (SAP1 and SAP2) and low when applied after emergence (SAP3). Prosulfocarb allowed a gain of 7.3% of durum wheat yield. The ryegrass infestation (92.5 plants/m²) affected the number of grains per spike and caused durum wheat yield losses of up to 39%. Key words: Herbicide, yield loss, Prosulfocarb, Ryegrass, Resistance, Tunisia.Le ray-grass (Lolium rigidum Gaud.) a développé de la résistance aux herbicides inhibiteurs de l’Acétolactate Synthase (ALS) et de l’Acétyl-CoA Carboxylase (ACCase). L’objectif de cette étude est d’évaluer l’effet du Prosulfocarbe, pulvérisée en post-semis prélevée à différentes doses et associée au S-métolachlore, sur le ray-grass résistant à la dose homologuée (3200 g ha-1) et en fonction des stades d’application (SAP1: 1 jour après le semis du blé, SAP2: 7 jours après le semis et SAP3: 2 à 3 feuilles après la levée). On vise également d’étudier l’effet du Prosulfocarbe et des herbicides de post levée sur le rendement du blé dur et ses composantes. Des essais de terrain ont été installés, avec un dispositif expérimental en bloc aléatoire complet (RCBD), dans des parcelles de blé dur au nord de la Tunisie (Mateur/Bizerte). L’évaluation s’est étendue sur trois campagnes successives (2012/13 à 2014/15). Les résultats ont révélé que l’efficacité du prosulfocarbe s’améliore en fonction de l’augmentation des doses d’application. Le S-métolachlore a favorisé l’amélioration de l’efficacité du prosulfocarbe de 6 à 15%. L’efficacité du prosulfocarbe est meilleure aux deux premiers stades d’application (SAP1 et SAP2) et faible en application après la levée (SAP3). Le prosulfocarbe a permis un gain de rendement de 7,3% du blé dur. Le ray-grass (92,5 plantes/m²) a affecté le nombre de grains par épi du blé dur et a causé des pertes de rendement qui peuvent atteindre 39%. Mots clés: Herbicide, Perte de rendement, Prosulfocarbe, Ray-grass, Résistance, Tunisie

Linear and Nonlinear Characterizations of Chalcogenide Photonic Crystal Fibers

International audienceIn this paper, we investigate the linear and nonlinear properties of GeSbS and AsSe chalcogenide photonic crystal fibers. Through several experimental setups, we have measured the second- and third-order chromatic dispersion, the effective area, losses, birefringence, the nonlinear Kerr coefficient as well as Brillouin and Raman scattering properties

Usefulness of drug provocation tests in children with a history of adverse drug reaction

PurposeThere are very few reports of adverse drug reactions (ADR) and almost no study of drug provocation test (DPT) in Korean children. We aimed to assess the role of DPT in children with unpredictable ADRs, and compare the causative drugs and clinical characteristics between detailed history of ADRs and result of DPTs.MethodsWe included 16 children who were experienced ADRs referred to pediatric allergy clinic at Ajou University Hospital (January 2006 to December 2009). With various suspected drugs, 71 DPTs were done in 16 patients using our own protocol, and skin tests to antibiotics were combined in ADRs to antibiotics in medical history.ResultsThere were 17 (23.9%) positive DPTs results out of 71 individual DPTs, and 11 patients (68.8%) from 16 patients were positive to at least one drug. Drugs causing positive reactions were acetaminophen in 5 (31%), Non-steroidal anti-inflammatory drugs in 4 (25%), penicillin in 3 (19%), cephalosporin in 2 (13%), and cotrimoxazole, macrolide and lactose in 1 each.ConclusionDPT seems a safe and useful procedure to confirm causative drug and identify safely administering alternative drugs in children with ADR