679 research outputs found

    Feasibility study of a natural vinaigrette from olive (Olea europaea) oil and lemon (Citrus limonium) juice-based lemon albedo extract

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    The present paper reports on the feasibility study of a natural vinaigrette from olive (Olea europaea) oil and lemon (Citrus limonium) juice-based lemon albedo extract. The albedo extract was prepared at different albedo to lemon juice ratios. The physical stability of different vinaigrette samples, in terms of creaming behaviour, was adopted as quality criterion. The most stable sample was then analysed for its rheological behaviour. According to preliminary results, the most physically stable vinaigrette could be obtained at albedo: lemon juice ratio of 1:15.1 (w/w). The corresponding dressing showed a stability of six days and a shear-thinning type rheological behaviour. So, the formulation of natural vinaigrette from olive oil, lemon juice and lemon albedo is feasible but such formulation is of short-term physical stability, which is a general well-known characteristic of natural and minimally processed food products. In our opinion, this study merits further research, in order to: i) better optimize the vinaigrette formulation, and ii) characterize the functional properties of the final product

    Construction de réponses coopératives : du corpus à la modélisation informatique

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    Les stratégies utilisées pour la recherche d’information dans le cadre du Web diffèrent d’un moteur de recherche à un autre, mais en général, les résultats obtenus ne répondent pas directement et simplement à la question posée. Nous présentons une stratégie qui vise à définir les fondements linguistiques et de communication d’un système d’interrogation du Web qui soit coopératif avec l’usager et qui tente de lui fournir la réponse la plus appropriée possible dans sa forme et dans son contenu. Nous avons constitué et analysé un corpus de questions-réponses coopératives construites à partir des sections Foire Aux Questions (FAQ) de différents services Web aux usagers. Cela constitue à notre sens une bonne expérimentation de ce que pourrait être une communication directe en langue naturelle sur le Web. Cette analyse de corpus a permis d’extraire les caractéristiques majeures du comportement coopératif et de construire l’architecture de notre système informatique webcoop, que nous présentons à la fin de cet article.Algorithms and strategies used on the Web for information retrieval differ from one search engine to another, but, in general, results do not lead to very accurate and informative answers. In this paper, we describe our strategy for designing a cooperative question answering system that aims at producing the most appropriate answers to natural language questions. To characterize these answers, we collected a corpus of cooperative question in our opinion answer pairs extracted from Frequently Asked Questions. The analysis of this corpus constitutes a good experiment on what a cooperative natural language communication on the Web could be. This analysis allows for the elaboration of a general architecture for our cooperative question answering system webcoop, which we present at the end of this paper

    Dérivation d’un spectre de réponse spécifique au site de la grande mosquée d’Alger (Algérie)

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    The estimation of the soil seismic response at the surface can be made by several experimental methods, approximate and numerical. This study consists in using numerical simulation to determine the surface response in terms of maximum acceleration and response spectrum of soil profiles located at the site of the Grand Mosque of Algiers, taking into account the soil’s non-linearity behavior, with an equivalent linear behavior (hysteresis degradation of the shear modulus G). The responses calculated on the surface that they are amplified or de-amplified compared to the excitation at the base (earthquake of May 21, 2003 in Boumerdès) indicate the presence of the site effects and which allows the derivation of a spectrum calculation to the studied site.L’estimation de la réponse sismique en surface du sol peut être faite par plusieurs méthodes expérimentales, approchées et numériques. Cette étude consiste à utiliser la simulation numérique pour déterminer la réponse en surface en termes d’accélération maximale et spectre de réponse des profils de sol localisé au niveau du site de la mosquée d’Alger en tenant compte de la non-linéarité du comportement du sol, avec un comportement linéaire équivalent (dégradation hystérésis du module de cisaillement G). Les réponses calculées en surface qu’elles soient amplifiées ou dés-amplifiées par rapport à l’excitation à la base (séisme du 21 Mai 2003 à Boumerdès) nous indiquent la présence des effets de site et ce qui permet la dérivation d’un spectre de calcul spécifique au site étudié

    Experimental study and modeling of the mechanical behavior of recycled aggregates-based high-strength concrete

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    Concrete, a material of prime importance, is widely used in various works. Among the raw materials composing concrete, aggregates come first. It is widely acknowledged that the consumption of natural aggregates increases with the growth in the amount of concrete needed. It has recently emerged that concrete waste can be recycled and reused in civil engineering works after a series of treatments. Moreover, in order to protect the environment and based on the principles of sustainable development, it was considered urgent to produce a High Strength Concrete incorporating recycled materials in addition to silica fume and a high-efficiency superplasticizer. This would certainly help to establish a harmonious sustainable development that guaranties the ecological balance and environmental protection, and prevents the depletion of natural resources. This study is part of a larger research program that that seeks to recover, recycle and valorize construction and demolition wastes. The main objective sought in this article is firstly to use aggregates from demolition concrete in the manufacture of a new concrete with high mechanical and rheological performance, and secondly, to model the behavior of this type of concrete using the Finite Element Method. This modeling aims to evaluate the maximum compressive strengths and compare them with those obtained experimentally

    BSA-binding studies of 2- and 4-ferrocenylbenzonitrile: voltammetric, spectroscopic and molecular docking investigations

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    The binding affinity of 2-ferrocenylbenzonitrile (2FBN) and 4-ferrocenylbenzonitrile (4FBN) with bovine serum albumin (BSA) has been investigated by cyclic voltammetry, absorption spectroscopy and molecular modelling techniques.  The results indicated that both of the two derivatives could bind to BSA and cause conformational changes with the order 2FBN > 4FBN. The voltammetric behavior of 2FBN and 4FBN before and after the addition of the BSA suggests that the redox process is kinetically controlled by the diffusion step, and demonstrated that the diffusion coefficients of the 2FBN-BSA and 4-FBN-BSA adducts are lower than that of the free compounds. Furthermore, molecular docking suggested that the binding mode of the two compounds to BSA is of hydrophobic and hydrogen bond interactions, moreover the ligand 2FBN additionally show a π-cation interaction.</p

    The Deformability of a High Performance Concrete (HPC)

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    AbstractThe current tendency in the world is to find new materials at lower cost which can guarantee better performances during their incorporations in the concretes. Our study lies within the scope of the valorization of local materials. Among these materials we find the high performance concrete, which has become the object of the several researchers for a few years.This study consists the development and the mechanical and elastic properties of a concrete with high performances (HPC) starting from materials existing on the Algerian market.Three mineral additions: limestone, the sand of dune and the waste of polishing of tiling are incorporated a cement with various contents (5%, 10%, 15% and 20%). instead of the fume of silica or fly-ashes

    Optimization of High-Performance-Concrete properties containing fine recycled aggregates using mixture design modeling

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    This investigation means to predict and modeling the fresh and hardened concrete behavior containing fine aggregates from concrete and brick wastes, for different recycled aggregates substitution rates. To succeed this, the design of experiments DOE method was used. It is observed that slump of recycled concrete is significantly influenced by the content in recycled concrete aggregates (RCA), natural sand (NS) and recycled brick aggregates (RBA), respectively.The compressive strength (CS) reaches a maximum value of 83.48 MPa with factors values of 25% RBA, and 75% RCA. And HPC’s based on RBA sand presented greater values of flexural strength at 7 days than HPC’s based on RCA sand, it was revealed that this is due to the RBA fines pozzolanic reaction and the production of new CSHs, which leads to better cement matrix densification.Under optimal conditions, themaximum desirability is 0.65, who has given HPC no added natural sand, by mixing recycled sands RBA (9.5%) with RCA (90.5%).The statistical terms result show that the expected models are very well correlated with the experimental data and have shown good accuracy
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