CONTRIBUTION A L’ETUDE DE LA FORMATION DU SILICIURE DE TITANE Ti/Si(B), TiN/Ti/Si(B) MISE EN EVIDENCE D’UN MODELE THERMODYNAMIQUE

Dans les nouvelles technologies des circuits intégrés, il est nécessaire que la résistivité des interconnexions soit très faibles, laconcentration des dopants aux contacts siliciure/silicium détermine directement cette résistance. Parmi ces dopants il y al’arsenic et le bore qui se caractérisent par des comportements variés d’un siliciure à un autre.Dans ce travail nous allons suivre le comportement du bore implanté dans un substrat de silicium avant le dépôt de la couchemétallique. Le titane est un métal très réactif avec l’oxygène pour cela nous avons utilisé l’encapsulation. Nous faisons le pointquant à l’effet de l’encapsulation par rapport à des échantillon non encapsulés.Cette étude a été menée en recuit thermique rapide. L’analyse des échantillons se fait par le rétro diffusion des particules(RBS). Les résultats seront traité par un modèle basé sur la chaleur effective de formation ce modèle qui s’appliquer bien pourles siliciures pures (sans présence des dopants ou autres impuretés). Nous avons élaboré un modèle général qui tient comptedes impureté

Decolorization of Basic Red 5 in aqueous solution by Advanced Oxidation Process using Fenton’s reagent

Fenton reagent was employed to decolorize the aqueous solution containing a dye (Basic Red 5). The effects of initial FeSO4 concentration, initial dye concentration and initial H2O2 concentration on the decolorization of Basic red 5 were investigated. The decolorization  efficiency increase with the rise of FeSO4 concentration  and  H2O2 concentration. However the decolonization efficiency was decreased with increase of dye concentration. The optimal operation parameters for the Fenton oxidation of Basic Red 5 were  [H2O2]0 = 25.50 mg/L and [Fe2+]0 = 20.00 mg/L for [dye]0 = 45.00 mg/L under acidic conditions at room temperature. Under these conditions, 88.71% decolorization efficiency of dye in aqueous solution was achieved after 30 min of reaction.

The Palm oil from seed of Phoenix dactylifera (Oil of both Deglet Nour and Kentichi) as a natural antioxidants and Environment-Friendly inhibitors on the Corrosion of mild Steel in HCl 1M

The flora of Republic of Algeria comprises a lot of Palm species, including Phoenix dactylifera. In this work, we used the Palm oil from seed of Phoenix dactylifera (Oil of both Deglet Nour and Kentichi). The objective of this study is divided into two parts. Firstly, determine the antioxidant activity of Palm oil from seed of Phoenix dactylifera (Oil of both Deglet Nour and Kentichi) according to the DPPH radical scavenging assay to suggest it as a new potential source of natural antioxidants, secondly, study the effect of inhibiting Palm oil from seed of Phoenix dactylifera (Oil of both Deglet Nour and Kentichi) on corrosion of mild steel in hydrochloric acid by electrochemical methods. Furthermore, The DPPH scavenging activity of Oil of both Deglet Nour and Kentichi increased in the order, Deglet Nour Oil < Kentichi Oil < ascorbic acid. The results of the polarization curves show that the corrosion current density decreases 577.9 μA/cm2 to 58μA/cm2 and to 59.3 μA/cm2 after addition of the inhibitor (oil of Deglet Nour and Kentichi respectively). The charge transfer resistance increases 21.69 ohm.cm2 to 186.5 ohm.cm2 and to 222.8 ohm.cm2 in the electrochemical impedance spectrum after addition of oil of Deglet Nour and Kentichi respectively. The inhibition of the compound effect is attributed to the formation of a film on the surface of the steel.

The Gum Arabic in the southern region of Morocco

Gum arabic (GA) of the Marocco  is a branched-chain, complex polysaccharide, either neutral or slightly acidic, found as a mixed calcium, magnesium and potassium salt of a polysaccharide acid. The backbone is composed of 1,3-linked β - D- galactopyranosyl units. The side chains are composed of two to five 1,3- linked b- D- galactopyranosyl units, joined to the main chain by 1, 6- linkages. Gum acacia (GA) is used in pharmaceutical, cosmetic and food industries as an emulsifier and stabilizer, and in some countries in the traditional treatment of patients with chronic kidney disease (CKD). Different brands of GA are commercially available, but their comparative efficacy against adenine-induced CKD is unknown. The purpose of this study is to determine the écologic characteristics who assured the Acacia gum in the area of Morocco, its development and reproduction in an arid environment, as in our are

Effects of Juglans regia Root Bark Extract on Platelet Aggregation, Bleeding Time, and Plasmatic Coagulation: In Vitro and Ex Vivo Experiments

Platelets have an important role in thrombosis and haemostasis. Hyperactivity of the platelets has been associated with thromboembolic diseases and represents the main cause of complications of cardiovascular diseases. Crude aqueous extract (CAE) of Juglans regia root bark was evaluated for bleeding time, antiaggregant activity by using agonists, thrombin, ADP, collagen, or arachidonic acid (in vitro and ex vivo), and anticoagulant activity by measuring the clotting parameters: activated partial thromboplastin time, prothrombin time, thrombin time, and fibrinogen dosage (in vitro and ex vivo). The result of this study reported that the strongest antiaggregant effect of CAE in vitro was observed on the ADP-induced aggregation with inhibitions up to 90 %, while, in ex vivo experiments, the inhibition (more than 80 %) was observed with all agonists. Anticoagulant effect of CAE significantly prolonged the TT and decreased the fibrinogen level in vitro and ex vivo without interfering with APTT and PT. The bleeding time in mice and rats was significantly increased by CAE. The antiplatelet and anticoagulant effect observed in this study suggest that Juglans regia could have antithrombotic and/or thrombolytic activities and provide an alternative therapy against thrombotic complications related to cardiovascular diseases

Extraction of organochlorine pesticides by a matrix of calcium phosphate

Accumulations of waste pesticides from manufacturing units of pesticides in rivers through drains are sources of environmental pollution. Search for matrices having a large capacity for retention of these pollutants is necessary. We conducted an experimental study on the purification of a mixture of pesticides on a column filled with a matrix based on calcium phosphate (hydroxyapatite). The study provides a satisfactory extraction of organochlorines with a very good performance, organochlorines Landa-cyhalothrin, Délthaméthrine, Beta-endosulfon, Endosulfon-Sulfate, Landa-cyhalothrin, Tertadifon, Delthamethrine, Fenarimol and iprodione have achieved satisfactory recovery percentages. The results and interpretations were confirmed by physico-chemical analyzes, using appropriate methods of investigation

Natural product based composite for extraction of arsenic (III) from waste water

Abstract Natural based composites of hydroxyapatite/Gum Arabic designed for removal of toxic metal arsenic (III) from waste water were synthesized and evaluated. Several composites with various compositions were prepared by the wet chemical method and analyzed using various spectroscopic and analytical methods such as: Fourier transform infrared spectroscopy, total organic carbon production, XRD analysis and scanning electron microscope. The rates of weight loss and water absorption of the HAp/GA composites as a function of time were evaluated in phosphate-buffered saline solution at 37 °C and a pH of 7.4. The effects of several variables on adsorption of arsenic (III) by HAp/GA composites were evaluated. The variables include arsenic (III) concentration, contact time (t) and complex surface nature of HAp/GA composite. Three surface complexation models were used to study the mechanisms controlled the adsorption. The models were Langmuir, Freundlich and Dubinin Radushkevich. The adsorption kinetic of arsenic (III) on the composite surface was described by three modes: pseudo first order, pseudo second order and the intra particle diffusion. The results revealed that, the rate of adsorption of arsenic (III) by HAp/GA composites was controlled by two main factors: the initial concentration of arsenic (III) and the contact time. The kinetic studies also showed that, the rate of adsorption is a second order. The results indicate that, composite offered in this study could be a valuable tool for removing toxic metals for contaminated water by adsorption. Graphical abstract