Search results for: Dalila De Pasquale

Authors: Alina Beraudi, Simona Catalani, Dalila De Pasquale, Eva Bianconi, Umberto Santoro, Susanna Stea, Pietro Apostoli

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Recently the European Community, in line with the international scientific community such as with the Consensus Statement, has determined to stop the use of metal-on-metal big head stemmed hip prosthesis. Among the factors accounted as responsible for the high failure rates of these hip implants are the release and accumulation of metal ions. Many studies have correlated the presence of these ions, besides other factors, with the induction of oxidative stress response. In our study on 12 subjects, we observed the patient specific capability to eliminate metal ions after revision surgery. While for cobalt all the patients were able to completely excrete cobalt ions within 5-7 months after metal-on-metal bearing removal, for chromium ions it didn’t happen. If on the one hand the toxicokinetic differences between the two types of ions are confirmed by toxicological and occupational studies, on the other hand, this peculiar way of exposition represents a novel and important point of view. Thus, two different approaches were performed to better understand the subject specific capability to transport metal ions (albumin study) and to manage the response to them (heme-oxygenase-1 study): - a mutational screening of ALBUMIN gene was conducted in 30 MoM prosthetic patients resulting in the absence of nucleotidic changes compared with the ALB reference sequence. To this study was also added the analysis of expression of modified albumin protein; - a gene and protein expression study on 44 patients of heme-oxygenase-1, that is one of the most important antioxidant enzyme induced by metallic ions, was performed. This study resulted in no statistically significant differences in the expression of the gene and protein heme-oxygenase-1 between prosthetic and non-prosthetic patients, as well as between patients with high and low ions levels. Our results show that the protein studied (albumin and heme-oxygenase-1) seem to be not involved in determining chromium and cobalt ions level. On the other hand, achromium and cobalt elimination rates are different, but similar in all patients analyzed, suggesting that this process could be not patient-related. We support the importance of researching more about ions transport within the organism once released by hip prosthesis, about the chemical species involved, the districts where they are contained and the mechanisms of elimination, not excluding the existence of a subjective susceptibility to these metals ions.

Keywords: chromium, cobalt, hip prosthesis, individual susceptibility

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Authors: Wiem Ben Khalifa, Dalila Souilem, Mahmoud Neji

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The evolutions of Social Web and Semantic Web lead us to ask ourselves about the way of supporting the personalization of learning by means of intelligent filtering of educational resources published in the digital networks. We recommend personalized courses of learning articulated around a first educational course defined upstream. Resuming the context and the stakes in the personalization, we also suggest anchoring the personalization of learning in a community of interest within a group of learners enrolled in the same training. This reflection is supported by the display of an active and semantic system of learning dedicated to the constitution of personalized to measure courses and in the due time.

Keywords: Semantic Web, semantic system, ontology, evaluation, e-learning

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Authors: Dalila Chouder, Djaafer Benachour

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This work concerns the study of the adsorption of metal ions Ag +, Mg +, and Ni2+ in aqueous medium by polydibenzoether-ROWN based on three factors: Temperature, time and concentration. The polydibenzoether crown was synthesized by two means: Chemical and electrochemical. The behavior of the two polymers has been different, and turns out very interesting for chemical polydibenzoether crown has identified conditions. Chemical and électronique polydibenzoether crown have different extraction screw vi property of adsoption of ions fifférents, this study also shows that plyméres doped may have an advantageous electrical conductivity.

Keywords: polymerization, electrochemical, conductivity, complexing metal ions

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Authors: Samra Isadounene, Amar Boukerrou, Dalila Hammiche

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In this work, the composites were prepared with poly(lactic acid) (PLA) and olive husk flour (OHF) with different percentages (10, 20 and 30%) using extrusion method followed by injection molding. The morphological, mechanical properties and thermal behavior of composites were investigated. Tensile strength and elongation at break of composites showed a decreasing trend with increasing fiber content. On the other hand, Young modulus and storage modulus were increased. The addition of OHF resulted in a decrease in thermal stability of composites. The presence of OHF led to an increase in percentage of crystallinity (Xc) of PLA matrix.

Keywords: biopolymers, composites, mechanical properties, poly(lactic acid)

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Authors: Pasquale Porcu, Mireille Vonlanthen, Gerardo Zaragoza-Galán, Ernesto Rivera

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In this work, we report the synthesis of a novel series of dendritic molecules bearing donor-acceptor groups (pyrene-bodipy) with potential applications in energy transfer. Initially, first and second generation Fréchet type dendrons (Py2-G1OH and Py4-G2OH) were prepared from 1-pyrenylbutanol and 3,5-dihydroxybenzylic alcohol. These compounds were further linked to a bodipy unit via an esterification reaction in order to obtain the desired products (Bodipy-G1Py2) and Bodipy-G2Py4). These compounds were fully characterized by FTIR and 1H and 13C NMR spectroscopy and their molecular weights were determined by MALDITOF. The optical and photophysical properties of these molecules were evaluated by absorbance and fluorescence spectroscopy, in order to compare their behaviour with other analogue molecules.

Keywords: bodipy, dendritic molecules, optical properties, pyrene

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Authors: Yassine Meraihi, Dalila Acheli, Rabah Meraihi

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MANET for Mobile Ad hoc NETwork is a collection of wireless mobile nodes that communicates with each other without using any existing infrastructure, access point or centralized administration, due to the higher mobility and limited radio transmission range, routing is an important issue in ad hoc network, so in order to ensure reliable and efficient route between to communicating nodes quickly, an appropriate routing protocol is needed. In this paper, we present the performance analysis of two mobile ad hoc network routing protocols namely DSR and OLSR using NS2.34, the performance is determined on the basis of packet delivery ratio, throughput, average jitter and end to end delay with varying pause time.

Keywords: DSR, OLSR, quality of service, routing protocols, MANET

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Authors: Amro Issam Hamed Attia Ramadan, Marco Zappatore, Pasquale Balena, Antonella Longo

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Considering the energetic crisis that is hitting Europe, it becomes more and more necessary to change the energy policies to depend less on fossil fuels and replace them with energy from renewable sources. This has triggered the urge to use clean energy not only to satisfy energy needs and fulfill the required consumption but also to decrease the danger of climatic changes due to harmful emissions. Many countries have already started creating energetic communities based on renewable energy sources. The first step to understanding energy needs in any place is to perfectly know the consumption. In this work, we aim to estimate electricity consumption for a municipality that makes up part of a rural area located in southern Italy using forecast models that allow for the estimation of electricity consumption for the next ten years, and we then apply the same model to the province where the municipality is located and estimate the future consumption for the same period to examine whether it is possible to start from the municipality level to reach the province level when creating energy communities.

Keywords: ARIMA, electricity consumption, forecasting models, time series

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Authors: Brahim Bahloul, Khatir Babesse, Azzedine Dkhira, Yacine Bahloul, Dalila Hammoutene

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In this paper, we investigate with ab initio calculations some structural and optoelectronic properties of Li₂S compound. The structural and electronic properties of the Li₂S antifluorite structure have been studied by first-principles calculations within the density functional theory (DFT), whereas the optical properties have been obtained using empirical relationships such as the modified Moss relation. Our calculated lattice parameters are in good agreement with the experimental data and other theoretical calculations. The electronic band structures and density of states were obtained. The anti-fluorite Li₂S present an indirect band gap of 3.388 eV at equilibrium. The top of the valence bands reflects the p electronic character for both structures. The calculated energy gaps and optical constants are in good agreement with experimental measurements.

Keywords: Ab initio calculations, antifluorite, electronic properties, optical properties

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Authors: Yassine Meraihi, Dalila Acheli, Rabah Meraihi

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Vehicular Ad hoc Network (VANET) is a special case of Mobile Ad hoc Network (MANET) used to establish communications and exchange information among nearby vehicles and between vehicles and nearby fixed infrastructure. VANET is seen as a promising technology used to provide safety, efficiency, assistance and comfort to the road users. Routing is an important issue in Vehicular Ad Hoc Network to find and maintain communication between vehicles due to the highly dynamic topology, frequently disconnected network and mobility constraints. This paper evaluates the performance of two most popular proactive routing protocols OLSR and DSDV in real city traffic scenario on the basis of three metrics namely Packet delivery ratio, throughput and average end to end delay by varying vehicles density and transmission range.

Keywords: DSDV, OLSR, quality of service, routing protocols, VANET

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Authors: Dalila Bouamra, Chekib Arslane Baki, Abdelhamid Bouchebour, Fatiha Koussa, Amel Benamara, Seoussen Kada

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The activity of methanolic extract from Anacyclus pyrethrum was evaluated using λ-carrageenan 1% induced paw edema in Wistar Albinos rats. The oral administration of 200 mg/kg, 400 mg/kg and 600 mg/kg, body weight of methanolic extract, one hour before induction of inflammation, exerted a significant inhibition effect of 47%, 57% and 62% respectively after 4h λ-carrageenan treatment and highly significant inhibition effect of 57%, 66% and 75% respectively after 8h λ-carrageenan treatment, compared to non treated group (100%) and that treated with aspirin, a standard anti-inflammatory drug. On the other hand, the effect of the plant extract on stomach was macroscopically and microscopically studied. The plant extract has an impact on the loss ratio of granulocytes that have invaded the stomach after a period of inflammation at a dose of 600 mg/kg body weight.

Keywords: inflammation, Anacyclus pyrethrum, gastritis, Wistar Albinos rats

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Authors: Rahma Tibigui, Ikram Hadj Said, Rachid Belkada, Dalila Hammoutene

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The vulnerability of industrial facilities is highly concerned with multiple risks from corrosion. The commonly adopted solution is based on the use of organic inhibitors, which are gradually being replaced by environmentally friendly organic inhibitors. In our work, we carried out a quantum chemical study based on the Density Functional Theory (DFT) method at the B3LYP/6-311G (d,p) level of theory. The inhibitory performance of a derivative of the tetrazole molecule has been investigated and reported as a carbon steel-friendly corrosion inhibitor in hydrochloric acid (HCl) medium. The relationship is likely to exist between the molecular structure of this compound as well as its various global reactivity descriptors, and its corrosion inhibition efficiency, which was examined and then discussed. The results show low values of ΔE, which represent strong adsorption of the inhibitor on the steel surface. Moreover, the flat adsorption orientation confirmed the great ability to donate (accept) electrons to (from) steel, fabricating an anchored barrier to prevent steel from corrosion.

Keywords: eco-friendly, corrosion inhibitors, tetrazole, DFT

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Authors: Dalila Oulhaci, Mohammed Zahaf

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The watering technique is essential to maintain a moist perimeter around the roots of the crop. This is the case with topical watering, where the soil around the root system can be kept permanently moist between the two extremes of water content. Moreover, one of the oldest methods used since Roman times throughout North Africa and the Near East was based on the repeated pouring of water into porous earthen vessels buried in the ground. In this context, these two techniques have been combined by replacing the earthen vase with plastic bottles filled with sand which release water through their perforated walls into the surrounding soil. The objective of this work is to first determine the purifying power of the activated sludge treatment plant of Toggourt and then that of the bottled Sawdust filter. For the station, the BOD purification rate was (96.5%), the COD purification rate was (87%) and suspended solids (90%). For the bottle, the BOD removal rate was (35%), and COD removal rate was (12.58%). This work falls within the framework of water saving, sustainable development and environmental protection, and also within the framework of agriculture.

Keywords: wasterwater, sawdust, purification, irrigation, touggourt (Algeria)

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Authors: Dalila Hocine, Mohammed Said Belkaid, Abderahmane Moussi

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In this study, pure rutile TiO2 thin films were directly synthesized on silicon substrates by Atmospheric Pressure Chemical Vapor Deposition technique (APCVD) using TiCl4 as precursor. We studied the physicochemical properties and the optical properties of the produced coatings by means of standard characterization techniques of Fourier Transform Infrared Spectroscopy (FTIR) combined with UV-Vis Reflectance Spectrophotometry. The absorption peaks at 423 cm-1 and 610 cm-1 were observed for the rutile TiO2 thin films, by FTIR measurements. The absorption peak at 739 cm-1 due to the vibration of the Ti-O bonds, was also detected. UV-Vis Reflectance Spectrophotometry is employed for measuring the optical band gap from the measurements of the TiO2 films reflectance. The optical band gap was then extracted from the reflectance data for the TiO2 sample. It was estimated to be 3.05 eV which agrees with the band gap of commercial rutile TiO2 sample.

Keywords: titanium dioxide, physicochemical properties, APCVD, FTIR, band gap

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Authors: Dalila Hammiche, Lisa Klaai, Sonia Imzi, Amar Boukerrou

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The fight against plastic pollution implies the development of polymers as alternatives to synthetic polymers. Starch is a natural polymer that can easily be plasticized by means of additives. The objective of this work is to develop and characterize biodegradable biofilms based on starch, plasticized by glycerol (20 and 30%). The elaboration of the biofilms was carried out by the casting method under simple conditions. The samples were characterized by infrared spectroscopy analysis with Fourier transform (FTIR), thermogravimetric analysis, and biodegradability test. Infrared spectral analysis showed that the 30% and 20% glycerol films have the same chemical structure and no functional group changes occurred. Thermogravimetric analysis showed that a 30% glycerol film has higher thermal stability than a 20% glycerol film. Biodegradability test showed that the lower the percentage of glycerol, the more easily the biofilm degrades.

Keywords: starch, natural sources, FTIR, thermogravimetric analysis, biodegradability test

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Authors: Angelo Aloisio Dag, Pasquale Pasca, Massimo Fragiacomo, Ferdinando Totani, Gianfranco Totani

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The estimate of the velocity of shear waves (Vs) is essential in seismic engineering to characterize the dynamic response of soils. There are various direct methods to estimate the Vs. The authors report the results of site characterization in Macerata, where they measured the Vs using the seismic dilatometer in a 100m deep borehole. The standard Vs estimation originates from the cross-correlation between the signals acquired by two geophones at increasing depths. This paper focuses on the estimate of the dependence of Vs on the wavenumber. The dispersion curves reveal an unexpected hyperbolic dispersion curve typical of Lamb waves. Interestingly, the contribution of Lamb waves may be notable up to 100m depth. The amplitude of surface waves decrease rapidly with depth: still, their influence may be essential up to depths considered unusual for standard geotechnical investigations, where their effect is generally neglected. Accordingly, these waves may bias the outcomes of the standard Vs estimations, which ignore frequency-dependent phenomena. The paper proposes an enhancement of the accepted procedure to estimate Vs and addresses the importance of Lamb waves in soil characterization.

Keywords: dispersion curve, seismic dilatometer, shear wave, soil mechanics

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Authors: Tofigh Hamidavi, Sepehr Abrishami, Pasquale Ponterosso, David Begg

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Structural design and analysis is an important and time-consuming process, particularly at the conceptual design stage. Decisions made at this stage can have an enormous effect on the entire project, as it becomes ever costlier and more difficult to alter the choices made early on in the construction process. Hence, optimisation of the early stages of structural design can provide important efficiencies in terms of cost and time. This paper suggests a structural design optimisation (SDO) framework in which Genetic Algorithms (GAs) may be used to semi-automate the production and optimisation of early structural design alternatives. This framework has the potential to leverage conceptual structural design innovation in Architecture, Engineering and Construction (AEC) projects. Moreover, this framework improves the collaboration between the architectural stage and the structural stage. It will be shown that this SDO framework can make this achievable by generating the structural model based on the extracted data from the architectural model. At the moment, the proposed SDO framework is in the process of validation, involving the distribution of an online questionnaire among structural engineers in the UK.

Keywords: building information, modelling, BIM, genetic algorithm, GA, architecture-engineering-construction, AEC, optimisation, structure, design, population, generation, selection, mutation, crossover, offspring

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Authors: Dalila Souilem, Salma Boumiza, Abdelkarim Abdelkader

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The Clarifier Dialogue Interface (CDI) is a part of an online teaching system based on human-machine communication in learning situation. This interface used in the system during the learning action specifically in the evaluation step, to clarify ambiguities in the learner's response. The CDI can generate patterns allowing access to an information system, using the selectors associated with lexical units. To instantiate these patterns, the user request (especially learner’s response), must be analyzed and interpreted to deduce the canonical form, the semantic form and the subject of the sentence. For the efficiency of this interface at the interpretation level, a set of substitution operators is carried out in order to extend the possibilities of manipulation with a natural language. A second approach that will be presented in this paper focuses on the object languages with new prospects such as combination of natural language with techniques of handling information system in the area of online education. So all operators, the CDI and other interfaces associated to the domain expertise and teaching strategies will be unified using FRAME representation form.

Keywords: dialogue, e-learning, FRAME, information system, natural language

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Authors: Touka Nassim, Tabli Dalila

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In this study, CuO thin films synthesized via simple sol-gel method, have been deposited on glass substrates by the spin coating technique and annealed at various temperatures. Samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), Fourier-transform infrared (FT-IR) and Raman spectroscopy, and UV-visible spectroscopy. The structural characterization by XRD reveals that the as prepared films were tenorite phase and have a high level of purity and crystallinity. The crystallite size of the CuO films was affected by the annealing temperature and was estimated in the range 20-31.5 nm. SEM images show a homogeneous distribution of spherical nanoparticles over the surface of the annealed films at 350 and 450 °C. Vibrational Spectroscopy revealed vibration modes specific to CuO with monolithic structure on the Raman spectra at 289 cm−1 and on FT-IR spectra around 430-580 cm−1. Electronic investigation performed by UV–Visible spectroscopy showed that the films have high absorbance in the visible region and their optical band gap increases from 2.40 to 2.66 eV (blue shift) with increasing annealing temperature from 350 to 550 °C.

Keywords: Sol-gel, Spin coating method, Copper oxide, Thin films

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Authors: Dalila Hammiche, Lisa Klaai, Amar Boukerrou

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Following this trend, natural fiber reinforcements have been gaining importance in the composites sector. The effectiveness of natural fiber–reinforced PLA composite as an alternative material to substitute the non-renewable petroleum-based materials has been examined by researchers. In this study, we investigated the physicochemical, particle size and distribution, and thermal behavior of prickly pear seed flour (PPSF). Then, composites were manufactured with 20% in PPSF. Thermal, morphological, and mechanical properties have been studied, and water absorption tests as well. The characterization of this fiber has shown that cellulose is the majority constituent (30%), followed by hemicellulose (27%). To improve the fiber-matrix adhesion, the PPS was chemically treated with alkali treatment. The addition of PPSF decreases the thermal properties, and the study of the mechanical properties showed that the increase in the fiber content from 0 to 20% increased Young’s modulus. According to the results, the mechanical and thermal behaviors of composites are improved after fiber treatment. However, there is an increase in water absorption of composites compared to the PLA matrix. The moisture sensitivity of natural fiber composites limits their use in structural applications. Degradation of the fiber-matrix interface is likely to occur when the material is subjected to variable moisture conditions.

Keywords: biopolymer, composites, alcali treatment, mechanical properties

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Authors: Amar Boukerrou, Ouerdia Belhadj, Dalila Hammiche, Jean Francois Gerard, Jannick Rumeau

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The main goal of this study is the investigation of alfa fiber content, treated with alkali treatment, on the thermal and mechanical properties of epoxy-amine matrix-based composites. The fibers were treated with 5% of sodium hydroxide solution and varied between 10% to 30% weight fractions. The tensile, flexural, and hardness tests are carried out to investigate the mechanical properties of composites. The results show those composites’ mechanical properties are higher than the neat epoxy-amine. It was noticed that the alkali treatment is more effective in the case of the tensile and flexural modulus than the tensile and flexural strength. The decline of both the tensile and flexural behavior of all composites with the increasing of the filler content was due probably to the random dispersion of the fibers in the epoxy resin The Fourier transform infrared (FTIR) was employed to analyze the chemical structure of epoxy resin before and after curing with amine hardener. FTIR and DSC analysis confirmed that epoxy resin was completely cured with amine hardener at room temperature. SEM analysis has highlighted the microstructure of epoxy matrix and its composites.

Keywords: alfa fiber, epoxy resin, alkali treatment, mechanical properties

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Authors: Dario Basile, Manuela De Maddis, Raffaella Sesana, Pasquale Russo Spena, Roberto Maiorano

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Nowadays, the reduction of CO₂ emissions and the decrease in energy consumption are the main aims of several industries, especially in the automotive sector. To comply with the increasingly restrictive regulations, the automotive industry is constantly looking for innovative techniques to produce lighter, more efficient, and less polluting vehicles. One of the latest technologies, and still developing, is based on the fabrication of the body-in-white and car parts through the stamping of Aluminum Tailor Welded Blanks. Tailor Welded Blanks (TWBs) are generally the combination of two/three metal sheets with different thicknesses and/or mechanical strengths, which are commonly butt-welded together by laser sources. The use of aluminum TWBs has several advantages such as low density and corrosion resistance adequate. However, their use is still limited by the lower formability with respect to the parent materials and the more intrinsic difficulty of laser welding of aluminum sheets (i.e., internal porosity) that, although its use in automated industries is constantly growing, remains a process to be further developed and improved. This study has investigated the effect of the main laser welding process parameters (laser power, welding speed, and focal distance) on the mechanical properties of aluminum TWBs made of 6xxx series. The research results show that a narrow weldability window can be found to ensure welded joints with high strength and limited or no porosity.

Keywords: aluminum sheets, automotive industry, laser welding, mechanical properties, tailor welded blanks

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Authors: Maria Amodeo, Pasquale Arpaia, Marco Buzio, Vincenzo Di Capua, Francesco Donnarumma

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Different deep neural network architectures have been compared and tested to predict magnetic hysteresis in the context of pulsed electromagnets for experimental physics applications. Modelling quasi-static or dynamic major and especially minor hysteresis loops is one of the most challenging topics for computational magnetism. Recent attempts at mathematical prediction in this context using Preisach models could not attain better than percent-level accuracy. Hence, this work explores neural network approaches and shows that the architecture that best fits the measured magnetic field behaviour, including the effects of hysteresis and eddy currents, is the nonlinear autoregressive exogenous neural network (NARX) model. This architecture aims to achieve a relative RMSE of the order of a few 100 ppm for complex magnetic field cycling, including arbitrary sequences of pseudo-random high field and low field cycles. The NARX-based architecture is compared with the state-of-the-art, showing better performance than the classical operator-based and differential models, and is tested on a reference quadrupole magnetic lens used for CERN particle beams, chosen as a case study. The training and test datasets are a representative example of real-world magnet operation; this makes the good result obtained very promising for future applications in this context.

Keywords: deep neural network, magnetic modelling, measurement and empirical software engineering, NARX

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Authors: Ali Zein Aalabiden Tlais, Alessio Da Ros, Pasquale Filannino, Olimpia Vincentini, Marco Gobbetti, Raffaella Di Cagno

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This study is an example of apple by-products (AP) recycling through a designed fermentation by selected autochthonous Lactobacillus plantarum AFI5 and Lactobacillus fabifermentans ALI6 used singly or as binary cultures with the selected Saccharomyces cerevisiae AYI7. Compared to Raw-, Unstarted- and Chemically Acidified-AP, Fermented-AP promoted the highest levels of total and insoluble dietary fibers, antioxidant activity, and free phenolics. The binary culture of L. plantarum AFI5 and S. cerevisiae AYI7 had the best effect on the bioavailability phenolic compounds as resulted by the Liquid chromatography-mass spectrometry validated method. The accumulation of phenolic acid derivatives highlighted microbial metabolism during AP fermentation. Bio-converted phenolic compounds were likely responsible for the increased antioxidant activity. The potential health-promoting effects of Fermented-AP were highlighted using Caco-2 cells. With variations among single and binary cultures, fermented-AP counteracted the inflammatory processes and the effects of oxidative stress in Caco-2 cells and preserved the integrity of tight junctions. An alternative and suitable model for food by-products recycling to manufacture a dietary supplement fortified with biogenic compounds was proposed. Highlighting the microbial metabolism of several phenolic compounds, undoubted additional value to such downstream wastes was created.

Keywords: apple by-products, antioxidant, fermentation, phenolic compounds

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Authors: Zahia Dorbane, Si Ammar Kadi, Dalila Boudouma, Thierry Gidenne

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In rabbits feeding, minimum fibre intake is essential to avoid digestive disorders. However, this concentration of fibre is not easy to obtain when formulating feeds, without reduction of nutritional value. Three stage olive cake, the residual material after oil extraction by centrifugation, including pulp and stones, can be used as a fibre source in rabbit diet. The incorporation of olive cake can allow a better balance between different fibre fractions and reduce health disorder. However, for practical use of any raw material, it is necessary to know its chemical and nutritive value. The aim of this study was to assess the nutritive value of three-stage olive cake (TSOC) for growing rabbits. Thus, 36 rabbits weaned at 35 days (702.8 ± 28.5) were divided into three groups of 12 receiving one of the following diets: control with 0% of TSOC, TSOC10 (10% of TSOC) and TSOC20 (20% TSOC). The rabbits were individually housed in digestibility cages and received ad libitum one of the three diets, fresh and clean water was provided ad libitum. After an adaptation period of 7d, feces were collected for 4d. Collected feces were frozen and stored for further analysis. The chemical composition of TSOC shows that it is a rich fiber raw material since it contains (%DM): 6% of CP; 7.4% of EE; 78.7% of NDF; 55.4% of ADF and 24.3% of ADL. The inclusion of TSOC at 20% of basal diet reduced the digestibility coefficient of organic matter, crude protein and NDF from 67.8 to 55.3%, 80.4 to 75.3% and from 31.5 to 18.4% (p < 0.001) respectively. The digestible energy and digestible protein content of the three-stage olive cake estimated by regression was 2.94 ± 0.52MJ DE/kg DM and 22.4 ± 6 g DP/kg DM respectively. In conclusion, based on the results of the present experiment, the three-stage olive cake can be used as a fibre source for rabbit.

Keywords: digestibility, nutritive value, olive cake, rabbit

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Authors: Mehdi Benlarbi, Dalila Oulhaci

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Several physical, human and economic factors come into play in the choice of an irrigation system for developing arid and semi-arid regions. Since it is impossible to define or weight quantitatively all the relevant factors in each case, the choice of the system is often based on subjective preferences rather than explicit analysis. Over the past decade, irrational irrigation in the Ouargla region has evolved to a certain extent based largely on water wastage and which may pose risks to the environment both off-site and at the site. In the whole region, the environment is damaged by excess water because the water tables that tend to be high form swamps that pollute nature on the surface. The purpose of our work is a comparison between sprinkler irrigation and drip irrigation using bottles. By irrigating with the aid of the bottle and giving a volume of 4 liters with a flow rate of one (1) liter per hour, the watering dose received varies between 6 and 7 mm without infiltration losses. And for the case of sprinkler irrigation, the dose received may not exceed 2.5mm. E in some cases, we have a quantity of water lost by infiltration. This shows that irrigation using the bottle is much more efficient than sprinkling. Because, on the one hand, a large amount of water is absorbed by the plant and on the other hand, there is no loss by infiltration. The results obtained are very significant because, on the one hand, we reuse local products, and on the other hand, as the bottles are buried, we avoid water losses by evaporation, especially in dry periods and salinization.

Keywords: resources, water, arid, evaporation, infiltration

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Authors: Mireille Vonlanthen, Pasquale Porcu, Ernesto Rivera

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Dendritic macromolecules are presenting unique physical and chemical properties. One of them is the faculty of transferring energy from a donor moiety introduced at the periphery to an acceptor moiety at the core, mimicking the antenna effect of the process of photosynthesis. The mechanism of energy transfer is based on the Förster resonance energy exchange and requires some overlap between the emission spectrum of the donor and the absorption spectrum of the acceptor. Since it requires a coupling of transition dipole but no overlap of the physical wavefunctions, the energy transfer by Förster mechanism can occur over quite long distances from 1 to a maximum of 10 nm. However, the efficiency of the transfer depends strongly on distance. The Förster radius is the distance at which 50% of the donor’s emission is deactivated by FRET. In this work, we synthesized and characterized a novel series of dendrimers bearing pyrene moieties at the periphery and a Ru (II) complex at the core. The optical and photophysical properties of these compounds were studied by absorption and fluorescence spectroscopy. Pyrene is a well-studied chromophore that has the particularity to present monomer as well as excimer fluorescence emission. The coordination compounds of Ru (II) are red emitters with low quantum yield and long excited lifetime. We observed an efficient singulet to singulet energy transfer in such constructs. Moreover, it is known that the energy of the MLCT emitting state of Ru (II) can be tuned to become almost isoenegetic with respect to the triplet state of pyrene, leading to an extended phosphorescence lifetime. Using dendrimers bearing pyrene moieties as ligands for Ru (II), we could combine the antenna effect of dendrimers as well as its protection effect to the quenching by dioxygen with lifetime increase due to triplet-triplet equilibrium.

Keywords: dendritic molecules, energy transfer, pyrene, ru-trisbipyridine complex

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Authors: Dalila Oulhaci, Mehdi Benlarbi, Mohammed Zahaf

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The irrigation method is fundamental for maintaining a wet bulb around the roots of the crop. This is the case with localized irrigation, where soil moisture can be maintained permanently around the root system between the two water content extremes. Also, one of the oldest methods used since Roman times throughout North Africa and the Near East is based on the frequent dumping of water into porous pottery vases buried in the ground. In this context, these two techniques have been combined by replacing the pottery vase with plastic bottles filled with sand that discharge water through their perforated walls into the surrounding soil. The first objective of this work is the theoretical determination using CLIMWAT and CROPWAT software of the irrigation doses of some crops (palm, wheat, and onion) and experimental by measuring the humidity of the soil before and after watering. The second objective is to determine the purifying power of the sand filter in the bottle. Based on the CROPWAT software results, the date palm needs 18.5 mm in the third decade of December, 57.2 mm in January, and 73.7 mm in February, whereas the doses received by experimentally determined by means of soil moisture before and after irrigation are 19.5 mm respectively, 79.66 mm and 95.66 mm. The onion needs 14.3 mm in the third decade of December of, 59.1 mm in January, and 80 mm in February, whereas the experimental dose received is 15.07 mm, respectively, 64.54 and 86.8 mm. The total requirements for the vegetative period are estimated at 1642.6 mm for date palms, 277.4 mm for wheat, and 193.5 mm for onions. The removal rate of the majority of pollutants from the bottle is 80%. This work covers, on the one hand, the context of water conservation, sustainable development, and protection of the environment, and on the other, the agricultural field.

Keywords: irrigation, sand, filter, humidity, bottle

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Authors: Nassim Belkacem, Amina Azzam, Dalila Haouchine, Kahina Bennacer, Samira Soufit

Abstract:

Objective: To evaluate the antioxidant activity of the methanolic extract along with the antimicrobial activity of the essential oil of the aerial parts of Rosmarinus officinalis L. collected in the region of Bejaia (northern center of Algeria). Materials and methods: The polyphenols and flavonoids contents of the methanolic extract were measured. The antioxidant activity was evaluated using two methods: the ABTS method and DPPH assay. The antimicrobial activity was studied by the agar diffusion method against five bacterial strains (Three Gram positive strains and two Gram negative strains) and one fungus. Results: The total polyphenol and flavonoid content was about 43.8 mg gallic acid equivalent per gram (GA Eq/g) and 7.04 mg quercetin equivalent per gram (Q Eq/g), respectively. In the ABTS assay, the rosemary extract has shown an inhibition of 98.02% at the concentration of 500ug/ml with a half maximal inhibitory concentration value (IC50) of 194.92ug/ml. The results of DPPH assay have shown that the rosemary extract has an inhibition of 94.67 % with an IC50 value of 17.87ug/ml, which is lower than that of Butylhydroxyanisol (BHA) about 6.03ug/ml and ascorbic acid about 1.24μg/ml. The yield in essential oil of rosemary obtained by hydrodistillation was 1.42%. Based on the determination of the diameter of inhibition, different antimicrobial activity of the essential oil was revealed against the six tested microbes. Escherichia coli from the University Hospital (UH), Streptococcus aureus (UH) and Pseudomonas aeruginosa ATCC have a minimum inhibitory concentration value (MIC) of 62.5µl/ml. However, Bacillus sp (UH) and Staphylococcus aureus ATCC have an MIC value of 125μl/ml. The inhibition zone against Candida sp was about 24 mm. The aromatograms showed that the essential oil of rosemary exercises an antifungal activity more important than the antibacterial one.

Keywords: Rosmarinus officinalis L., maceration, essential oil, antioxidant, antimicrobial activity

Procedia PDF Downloads 520

Authors: Dalila Lino

Abstract:

The power of play for learning and development in early childhood education is beyond question. The main goal of this study is to analyse how three contemporary early childhood pedagogical approaches, the High Scope, the Modern School Movement (MEM) and the Pedagogy of Participation integrate play in their curriculum development. From this main goal the following objectives emerged: (i) to characterize how play is integrated in the daily routine of the pedagogical approaches under study; (ii) to analyse the teachers’ role during children’s playing situations; (iii) to identify the types of play that children are more often involved. The methodology used is the qualitative approach and is situated under the interpretative paradigm. Data is collected through semi-structured interviews to 30 preschool teachers and through observations of typical daily routines. The participants are 30 Portuguese preschool classrooms attending children from 3 to 6 years and working with the High Scope curriculum (10 classrooms), the MEM (10 classrooms) and the Pedagogy of Participation (10 classrooms). The qualitative method of content analysis was used to analyse the data. To ensure confidentiality, no information is disclosed without participants' consent, and the interviews were transcribed and sent to the participants for a final revision. The results show that there are differences how play is integrated and promoted in the three pedagogical approaches. The teachers’ role when children are at play varies according the pedagogical approach adopted, and also according to the teachers’ understanding about the meaning of play. The study highlights the key role that early childhood curriculum models have to promote opportunities for children to play, and therefore to be involved in meaningful learning.

Keywords: curriculum models, early childhood education, pedagogy, play

Procedia PDF Downloads 206

Authors: Dalila Lino

Abstract:

Practicum is a central dimension of teacher education programs. Learning how to teach is, in effect, a complex process that integrates periods of observation, experimentation, reflection, planning, and evaluation in a real context of practices, providing opportunities for prospective teachers to understand the various dimensions of education and to implement the knowledge built over the theoretical courses they have taken. At the pre-service training of early childhood teachers, specialized guidance and in particular pedagogical supervision assumes a key role in the professional development of students in training. The main goal of this study is to describe and analyze the supervision process that occurs during the practicum of preschool education master programs in Portugal. The objectives of the study are: (i) to describe the cooperative process of professional development experienced by student teachers during the practicum; (ii) to identify the strengths and weaknesses of supervision process; (iii) to identify the supervision styles used by university supervisors and cooperating teachers. The methodology used is the mix-method research and data was collected through semi-structured interviews and online questionnaires. The participants are newly graduated Portuguese early childhood teachers, university supervisors and cooperating teachers. The results reveal gaps in the specialized training of cooperating teachers and university supervisors, a large number of trainees per supervisor, which makes it difficult to support students, and those interpersonal relationships between university supervisors and students and/or cooperating teachers and students interfere in the development of the supervisory processes. The study highlights the need to invest in the specialized training of university supervisors and cooperating teachers to create better opportunities to support the professional development of prospective teachers.

Keywords: mentoring, pedagogical supervision, practicum, preschool teacher education

Procedia PDF Downloads 149