A simple, rapid and sensitive spectrophotometric method has been proposed for the determination of La (III) using 3-hydroxy -4-(2-hydroxy-phenyl azo) naphthalene -1- sulfonic acid as a chromogenic reagent. This method is based on the formation of a red-pink colored complex, upon the reaction of La(III) with the reagent in an alkaline medium (pH= 9.50), having a maximum absorbance at 459 nm. Beer's law is valid in the concentration range 0.512 µg.ml-1 with a Sandell's sensitivity value of 0.0188 µg.cm-2 and molar absorptivity of 7376.12 L.mol-1.cm-1. The stoichiometric composition of the chelate is 1:3. The effect of the presence of different cations as interferants in the determination of La(III) under the given optimum conditions were investigated.
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Catalytic reduction is considered an effective approach for the reduction of toxic organic pollutants from the environment, but finding an active catalyst is still a big challenge. Herein, Ag decorated CeO2 catalyst was synthesized through polyol reduction method and applied for catalytic reduction (conversion) of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). The Ag decorated CeO2 catalyst displayed an outstanding reduction activity with 99% conversion of 4-NP in 5 min with a 0.61 min−1 reaction rate (k). A number of structural characterization techniques were executed to investigate the influence of Ag on CeO2 and its effect on the catalytic conversion of 4-NP. The outstanding catalytic performances of the Ag-CeO2 catalyst can be assigne
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Avec Jacques Prévert la poésie entre dans la vie quotidienne, avec des mots de tous les jours que comprennent même les enfants. Son recours à la langue parlée sert comme un outil pour exprimer sa contestation contre l’ordre établi. Adolescent pendant la première guerre mondiale, il était témoin du massacre de toute la génération précédente. Il manifeste une aversion profonde pour la guerre et les militaires. Il déteste également les prêtres, les politiciens et l’armée qui sont, pour lui, les responsables de l’amertume de la génération. À ce mouvement de la contestation d’une société, le poète répond par l’offre de valeurs positives qui changeront l’ordre du monde. Il propose d’ailleurs la vitalité c
... Show MoreLe but de la présente étude est de mettre en lumière la fragilité des personnages dans le roman de "Mme Bovary". En fait, la fragilité n'est pas uniquement propre aux héros de Flaubert. Nous pouvons attribuer cette caractéristique à la plupart des protagonistes du XIXe siècle. Nous pouvons dire qu'aucun auteur n'excelle autant que Flaubert à incarner cette fragilité.
Flaubert présente un personnage frustré de toute force et de toute volonté comme le personnage d'Emme Bovary.
Ce personnage n'a pas de confiance en soi, E
... Show MoreRESUMEN:
Pretendemos hacer con este trabajo un breve recorrido sobre lo que han dicho algunos gramáticos de las construcciones condicionales, a la par señalaremos los criterios que los mismos establecen y siguen para diferenciar entre distintos tipos de estructuras condicionales o entre las construcciones que ellos entienden o consideran como tales y las que no, atendiendo fundamentalmente a dos criterios; formal y semántico-pragmático. El presente trabajo tiene como objetivo la clasificación y la descripción de las construcciones condicionales, demostrando que no todas las condicionales son hipotéticas ni todas las hipotéticas son condicionales.
Abstract
We intend to make this work
... Show MoreThe main subject of this poem is a chance meeting between Baudelaire and unknown beautiful lady. Her presence represents the far-fetched, magnificent beauty. This beauty forms an aspect of idealism that takes its real existence and disappears immediately.
This emotional poem deals with the continuous despair that dates back to the Romantic age where it was a key topic; the passing woman embodies destiny. All this comes from constant experience and mad love through the poet’s view to a woman paving the way toward the unknown. Baudelaire, however, noticed this unknown through a passer-by that reflected the real and magical image of this unk
... Show MoreBackground. Dental implantation has become a standard procedure with high success rates, relying on achieving osseointegration between the implant surface and surrounding bone tissue. Polyether ether ketone (PEEK) is a promising alternative to traditional dental implant materials like titanium, but its osseointegration capabilities are limited due to its hydrophobic nature and reduced surface roughness. Objective. The aim of the study is to increase the surface roughness and hydrophilicity of PEEK by treating the surface with piranha solution and then coating the surface with epigallocatechin-3-gallate (EGCG) by electrospraying technique. Materials and Methods. The study includes four groups intended to investigate the effect of pir
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Abstract
The Non - Homogeneous Poisson process is considered as one of the statistical subjects which had an importance in other sciences and a large application in different areas as waiting raws and rectifiable systems method , computer and communication systems and the theory of reliability and many other, also it used in modeling the phenomenon that occurred by unfixed way over time (all events that changed by time).
This research deals with some of the basic concepts that are related to the Non - Homogeneous Poisson process , This research carried out two models of the Non - Homogeneous Poisson process which are the power law model , and Musa –okumto , to estimate th
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