2-[2-(1H-Imidazol-3-ium-5-yl)eth­yl]-3-(pyridin-2-yl)-2H-imidazo[1,5-a]pyridin-4-ium bis­(perchlorate)

In the title mol­ecular salt, C17H17N5 +·2ClO4 −, the dihedral angles between the fused-ring system and the pendant five- and six-membered heterocyclic rings are 6.4 (2) and 41.29 (19)°, respectively. The O atoms of both perchlorate anions are disordered over two sets of sites with occupancy ratios of 0.614 (8):0.386 (8) and 0.591 (7):0.409 (7). An intra­molecular C—H⋯N contact occurs in the cation. In the crystal, the components are linked by N—H⋯O and C—H⋯O hydrogen bonds and π–π stacking inter­actions [centroid–centroid separation = 3.642 (3) Å]

Investigation of inks, pigments and paper in four Moroccan illuminated manuscripts dated to the eighteenth century

UID/FIS/04559/2020 VICARTE UIDB/00729/2020The heritage left by the Arab world in the history of science is directly related to the innovations in both the manufacturing of paper and the production of ink. Four Moroccan manuscripts dating to the eighteenth century, conserved at the royal library of Rabat, have been analyzed by X-ray diffraction (XRD), energy-dispersive X-ray fluorescence spectrometry (EDXRF), scanning electron microscopy coupled to energy dispersive X-ray spectroscopy (SEM–EDS), Raman and attenuated total reflection Fourier transformed infrared spectroscopy (FTIR-ATR). The combination of the Raman, EDS, and EDXRF spectroscopies results allows us to Characterized the inorganic inks, pigments and fillers used in paper making process. Iron-based ink was used for writing the text for all manuscripts. The main pigments used in the titles and in the illuminated part are found to be vermillion and red ochre in red samples, azurite with barium white and ultramarine in blue color, lead chromate in yellow color, copper and arsenic based ink in green color, carbon black for black color and gold. The main fillers identified in paper are calcite and kaolin. FTIR-ATR and Raman analysis revealed the presence of the characteristic bands of cellulose, the main component of paper. XRD confirms the presence of the fillers detected by FTIR-ATR. Finally, SEM allows to have a better knowledge of the typical morphology of the paper highlighting some effects of the degradation process. Graphic abstract: [Figure not available: see fulltext.]publishersversionpublishe

Phenomenological prediction of desalination brines nanofiltration through the indirect determination of zeta potential

The prediction of nanofiltration (NF) performance at environmentally relevant conditions, e.g.: highly saline brine solutions, is becoming of increasing interest for the recovery of waste materials in the water desalination industry. In this work, the prediction of the separation of sulfate and chloride contained in the retentate of reverse osmosis brackish water desalination by means of the commercial NF270 membrane is studied. Prior to theoretical modelling, streaming potential measurements were performed for aqueous single and binary mixtures of NaCl and Na2SO4 within the range of ionic strengths 1-100 mol/m3. Zeta potential values were obtained applying an extrapolation method from recent literature to allow the calculation of surface charge density under higher ionic strengths found in reverse osmosis desalination brines (100-1200 mol/m3). Then, the obtained surface charge density was used to simulate sulfate, chloride and sodium rejections by means of the Donnan steric pore model (DSPM), in the pressure range 2-20 bar. The good agreement between experimental and simulated rejection values allows validating the approach that enables the prediction of NF performance for the separation of monovalent and divalent anions, of interest for the purification of desalination brines before their further exploitation as a source of sodium chloride concentrated solutions.The authors gratefully acknowledge the funding for the projects CTM2016-75509-R and CTQ2015-66078-R

Synthese asymetrique d'alpha-aminoacides phosphoniques et phosphono enkephalines

Available from INIST (FR), Document Supply Service, under shelf-number : T 84363 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueSIGLEFRFranc

Étude de l’efficacité de traitement d’eaux usées industrielles

This study aims to evaluate the effectiveness of treatment of the purification plant of the industrial effluents of company CBGN (Company of Fizzy drinks of the North of Fez).The study of purification performance of the station was carried out at various operating parameters of the STEP namely: pH, flow and temperature. And at bioreactor to evaluate the reports BOD5 and COD, suspended matter (SM) and the nutritive matters, nitrogen, phosphorus,…. for the growth of the micro-organisms.The results obtained show an effectiveness of treatment as of SM with an output which can reach 90 %.Cette étude a pour objectif d’évaluer l’efficacité de traitement de la station d’épuration des effluents industriels de la société CBGN (Compagnie des Boissons Gazeuses du Nord de Fès). L’étude des performances épuratoires de la station a été effectuée au niveau des différents paramètres de fonctionnement de la station d’épuration – STEP à savoir : le pH, débits, et température. Et au niveau de réacteur biologique pour évaluer les rapports en DBO5 (demande bioclinique en oxygène) et DCO (demande chimique en oxygène), les matières en suspension – MESet les matières nutritives, azote, phosphore, pour le développement des microorganismes. Les résultats obtenus montrent une efficacité de traitement des MES avec un rendement pouvant atteindre 90 %

Study of natural degradation effect on lignocellulose fibers of archaeological cedar wood: monitoring by Fourier Transform Infrared (FTIR) spectroscopy

The present work aims at elucidating the changes in the chemical composition of Moroccan cedar wood during exposure time to the natural degradation process. Correlation of these changes with certain physical properties and performance of this polymeric material were proposed. Four archaeological Cedrus atlantica wood samples dating from the 16th, 17th, 19th and 21st centuries were analyzed using Fourier Transform Infrared spectroscopy. The infrared spectroscopic analyses demonstrated in detail the significant changes that occurred in different molecular groups of lignocelluloses fibers, as evidenced by the decrease of band intensities related to the carbohydrates and lignin. The influence of the natural degradation process on these fibers was enhanced by the gradual decline in fingerprint (1800-800cm-1) related to the cellulose amount accompanied by the detection of new carbonyl band at 1650cm-1 attributed to the C=O quinone suggesting the lignin’s oxidation

Scanning Electron Microscopy examination of the surface of softwood attacked by fungus

The morphological structure of the surface of four Cedrus atlantica softwood samples was monitored by scanning electron microscope. The obtained results have shown formation of cracks on the surface of samples with deterioration of the majority of cellulosic fibers. The alteration of wood structure and decomposition of carbohydrates exploited by scanning electron microscopy images could act as a confidential sign of an advanced stage of wood decay by biological attacks, leading upon time to the extinction of this natural wealth. It appeared that the studied samples were attacked by brown-rot fungus selectively decaying the cell wall of softwood materials. The scanning electron microscope morphological observation revealed that microfibril distribution was heterogeneous and dynamic contact angles increase significantly during exposure to the non-controlled environmental conditions

Mesoporous Carbon from Optimized Date Stone Hydrochar by Catalytic Hydrothermal Carbonization Using Response Surface Methodology: Application to Dyes Adsorption

Providing efficient and environmental friendly ways to recover lignocellulosic waste remains a challenge around the world. In this study, citric acid-catalyzed hydrothermal carbonization (CHTC) was coupled with pyrolysis to convert date seed (Ds) into adsorbent material. In this regard, a central composite design (CCD) using response surface methodology (RSM) was developed to examine the influence of temperature, reaction time, and catalyst dose on the mass yield (Ym(%)) and carbon retention rate (CRR(%)) in the produced hydrochars. The optimized hydrochar (OHC-Ds) was obtained under optimal conditions (200°C, 120 min, 20 mg) and characterized by a Ym(%) and CRR(%) of 59.71% and 75.84%, respectively. Chemical activation by KOH of OHC-Ds followed by pyrolysis at 600°C resulted in an active material (AOHC-Ds) rich in carbon and characterized by a high specific surface area of 1251.5 m2/g, with the dominance of mesopores, as well as an amorphous structure comparable to graphite shown by X-ray diffraction (XRD) analysis. Adsorption experiments of two dyes on AOHC-Ds showed a high maximum adsorption capacity (Qm) of 657.89 mg g−1 for methylene blue (MB) and 384.61 mg g−1 for methyl orange (MO) compared to other conventional adsorbents. This result is due to the low acidity (pHpzc) of the surface of AOHC-Ds, which equals 6.75, and its surface, which is also rich in oxygenated functional groups such as (-OH), (C=O), and (C-O) shown by FTIR analysis. These results suggest that the coupling of CHTC and KOH activation followed by pyrolysis is an encouraging way to prepare an efficient and inexpensive adsorbent to remove dyes in wastewater

Seawater nanofiltration for the elaboration of usable salty waters

International audienceOur article deals with the possibilities to treat seawater using commercial nanofiltration polyamide membranes, denoted NF70 and NF 200, in order to elaborate usable salty aqueous solutions (from high concentrated solutions with total salinity around 70 g/L to isotonic solutions with total salinity in the range of 4 g/L). A theoretical part concerned a hydrodynamical model of mass transfer. This very simple model based on the permeate salt concentrations (using conductivity measurements) vs. the reverse of the permeate flux has been validated for the first time for seawater. This very interesting approach is able to quantify separately both parts of the mass transfer occurring in NF — convection and hydration-diffusion. This fundamental approach was developed in order to contribute to a better understanding of the selectivities observed between monovalent and divalent ions in NF operation. The experiments were conducted in Biarritz (south-west France) under coal pre-filter seawater, just after the Prestige's oil pollution, in order to elaborate personal body washing solutions using NF permeates. Concerning the concentrates we have contributed to the elaboration of hypertonic salty solutions for thalassotherapy centers or home bath applications. Indeed the possibilities of NF in reducing the overall salinity of seawater leads the way to potential applications in the field of human health (e.g., preparation of nasal sprays, medical dietetics, hot mineral springs). Furthermore our investigations conducted in the holy place of the Biarritz Seawater Museum have contributed to discovery of the possibilities of NF concentrates for coral growth studies