Cationic dyes adsorption onto high surface area ‘almond shell’ activated carbon: Kinetics,equilibrium isotherms and surface statistical modeling

Almond shell agricultural biomass was used to prepare high surface area activated carbon using potassium hydroxide as activating agent. The activated carbon (AC) was characterized using X-Ray photoelectron spectroscopy, X-Ray diffraction, Thermogravimetric and differential thermal analyses, Scanning electron microscopy, Fourier transform infrared, Brunauer–Emmett–Teller surface area and Raman spectroscopy. The AC was found to have a high surface area of 2054 m² g^?1. The influence of various key parameters was evaluated on the adsorption process including contact time, adsorbent dose and solution pH. Isotherm data were modeled using Langmuir and Freundlich models. Langmuir isotherm model presented the best fit to experimental data suggesting homogeneous distribution of adsorption sites. The adsorbent demonstrated high monolayer adsorption capacity of 833.33 and 625.0 mg/g for Methylene Blue and Crystal Violet, respectively. The efficiency of the adsorption process was linked to the micro-mesoporous structure and to the availability of the surface adsorption sites. Response surface methodology was used to optimize the removal efficiency from aqueous solution.     

A Multifunctional Photochromic Light-Modulating Polymer Film

Russian Journal of General Chemistry - The results of the authors’ studies on development of a multilayer photochromic sun-protective energy-saving polymer film able of reversibly changing...     

4-Aminopyrimidine libraries from the Ugi-Smiles reaction of thiouracil

The Ugi-Smiles reaction of S-benzyl thiouracil have been exploited in several three-step sequences for the preparation of aminopyrimidine libraries with high diversity. After the 4-component coupling, oxidation of the thioether to sulfone is followed by displacement of the latter by various carbon-centered nucleophiles (cyanide, malonate, boronic acids) or amines. The efficiency of the whole sequence was further demonstrated with one-pot procedures.     

Photochromic properties of modified nanodiamonds

A functionalization of the surface of detonation nanodiamonds by photochromic spirocompounds from the classes of spiropyrans and spirooxazines has been carried out for the first time. A comparative study of the interaction of nanodiamonds with positive and negative potential is performed by the spectral–kinetic method, which shows the possibility of surface modification by only functionalized molecules of spirocompounds with the formation of surface proton complexes. This is confirmed by the hypsochromic shift of the absorption bands of the photoinduced merocyanine forms of adsorbed molecules of spirocompounds and by the decrease of the speed of their dark relaxation to the initial state in the presence of nanodiamonds with a negative potential.     

Suites récurrentes linéaires : terme général et idempotents

In this Note, we show essentially two results. The first one consists in showing that the algebra of linear recurrence sequences is the direct sum of two sets. The second result consists in giving a characterisation of the idempotents of this algebra.     

Potassium Fluoride-Modified Clay as a Reusable Heterogeneous Catalyst for One-Pot Synthesis of 3,4-Dihydropyrimidin-2(1H)-ones

Russian Journal of Organic Chemistry - Potassium fluoride-modified clay collected from the region of Agadir (Morocco) was used as a hetaerogeneous catalyst in the one-pot synthesis of...     

Comparative study of nucleation and growth mechanism of cobalt electrodeposited on ITO substrate in nitrate and chloride electrolytes

Journal of Solid State Electrochemistry - A comparative study of the electrochemical deposition of cobalt on tin-doped indium oxide (ITO) substrate was carried out using electrochemical techniques...     

Hölder continuity of solutions to elastic traffic network models

This paper aims to study stability and sensitivity analysis for quasi-variational inequalities which model traffic network equilibrium problems with elastic travel demand. In particular, we provide a Hölder stability result under parametric perturbations.     

Highly Diastereoselective Synthesis of Functionalized β-Lactams

An efficient method based, on the acid chloride-imine reaction, is reported for the preparation of 1,3-disubstituted β-lactams in good yield and with high selectivity.