Natural phosphate supported Titania as a novel solid acid catalyst for oleic acid esterification

International audienceIn the present study, a novel solid acid catalyst based on titanium dioxide (2.5-10 wt%) supported on natural phosphate (TiO2/NP) was prepared by sol-gel process, and 10wt% loaded catalyst was characterized by several physicochemical techniques. The performances of synthesized catalyst were investigated in esterification of oleic acid with methanol. The catalytic performance was screened under different reaction conditions, namely, loading amount of TiO2, calcination temperature, molar ratio of methanol to oleic acid, reaction temperature and amount of catalyst. The catalyst showed a good stability under high reaction temperature and can be reused without severe loss of activity. As a versatile application, the TiO2(10)/NP catalyst exhibits a good ability for the esterification of free fatty acids in a highly acidic feedstock

Evaluation agronomique d’un engrais enrobé

The use of Coated Fertilizers (EE) is a promising direction that offers the possibility of improving the management of nutrient application by reducing environmental threats while maintaining high yields and good quality production. This research study aims to carry out an agronomic evaluation of a coated fertilizer based on biodegradable polymer through an elaborate experiment on tomato grown in greenhouses. The results showed that the application of EE helped to maintain tomato yield with an improvement trend (11.62kg/m² of fruit) compared to conventional fertilizer or Uncoated Fertilizer. (ENE) (11.25kg/m² of fruit). In addition, the significant increase in the efficiency of nitrogen use in the case of EE demonstrated an effective management of nitrogen and a better synchronization between the availability of nitrogen and its absorption by tomato. From this, it could be deduced that the coated fertilizer (ELC: 15-15-15) is able to satisfy the nitrogen needs of crops with a cycle similar to tomato or less short under controlled conditions.L'utilisation des Engrais Enrobés (EE) constitue une direction prometteuse qui offre la possibilité d'améliorer la gestion de l'application des nutriments par la réduction des menaces environnementales tout en maintenant des rendements élevés et une production de bonne qualité. Cette étude de recherche vise à effectuer une évaluation agronomique d’un engrais enrobé à base de polymère biodégradable à travers une expérimentation élaborée sur la tomate cultivée sous serre. Les résultats ont montré, que l'application de l’EE a permis de maintenir le rendement de la tomate avec une tendance d’amélioration (11.62kg/m² de fruits) par rapport à l’engrais conventionnel ou l’Engrais Non Enrobé (ENE) (11.25kg/m² de fruits). En outre, l’augmentation significative de l’efficience d’utilisation de l’azote en cas de l’EE a démontré une gestion efficace de l'azote et une meilleure synchronisation entre la disponibilité de l’azote et de son absorption par la culture de la tomate. De ce fait, on pourrait déduire que l’engrais enrobé (ELC : 15-15-15) est en mesure de satisfaire les besoins en azote des cultures à cycle similaire à la tomate ou moins court dans les conditions contrôlées

Agronomic evaluation of a coated fertilizer

L'utilisation des Engrais Enrobés (EE) constitue une direction prometteuse qui offre la possibilité d'améliorer la gestion de l'application des nutriments par la réduction des menaces environnementales tout en maintenant des rendements élevés et une production de bonne qualité. Cette étude de recherche vise à effectuer une évaluation agronomique d’un engrais enrobé à base de polymère biodégradable à travers une expérimentation élaborée sur la tomate cultivée sous serre. Les résultats ont montré, que l'application de l’EE a permis de maintenir le rendement de la tomate avec une tendance d’amélioration (11.62kg/m² de fruits) par rapport à l’engrais conventionnel ou l’Engrais Non Enrobé (ENE) (11.25kg/m² de fruits). En outre, l’augmentation significative de l’efficience d’utilisation de l’azote en cas de l’EE a démontré une gestion efficace de l'azote et une meilleure synchronisation entre la disponibilité de l’azote et de son absorption par la culture de la tomate. De ce fait, on pourrait déduire que l’engrais enrobé (ELC : 15-15-15) est en mesure de satisfaire les besoins en azote des cultures à cycle similaire à la tomate ou moins court dans les conditions contrôlées.The use of Coated Fertilizers (EE) is a promising direction that offers the possibility of improving the management of nutrient application by reducing environmental threats while maintaining high yields and good quality production. This research study aims to carry out an agronomic evaluation of a coated fertilizer based on biodegradable polymer through an elaborate experiment on tomato grown in greenhouses. The results showed that the application of EE helped to maintain tomato yield with an improvement trend (11.62kg/m² of fruit) compared to conventional fertilizer or Uncoated Fertilizer. (ENE) (11.25kg/m² of fruit). In addition, the significant increase in the efficiency of nitrogen use in the case of EE demonstrated an effective management of nitrogen and a better synchronization between the availability of nitrogen and its absorption by tomato. From this, it could be deduced that the coated fertilizer (ELC: 15-15-15) is able to satisfy the nitrogen needs of crops with a cycle similar to tomato or less short under controlled conditions

Na-doping approach for conductivity enhancement of natural phosphate derived fluorapatites

The search for thermally stable solid electrolytes is promising for solid-state batteries. High ionic conductivity solid electrolytes derived from natural phosphate modified by sodium addition were developed. The samples were characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, 23Na solid-state nuclear magnetic resonance and scanning electron microscopy with energy dispersive spectroscopy. The structural and morphology changes were observed by increasing the Na2SO4 content. The synthesized ceramic electrolytes have low activation energy of about 0.60 eV and a relatively high ionic conductivity of 2 × 10−2 mS cm−1 at 400 °C

Synergistic effect of cellulose nanocrystals/graphene oxide nanosheets as functional hybrid nanofiller for enhancing properties of PVA nanocomposites

Novel functional hybrid nanofillers composed of cellulose nanocrystals (CNC) and graphene oxide nanosheets (GON), at different weight ratios (2:1; 1:1 and 1:2), were successfully prepared and characterized, and their synergistic effect in enhancing the properties of poly (vinyl alcohol) (PVA) nanocomposites was investigated. Due to the synergistic reinforcement, it was found that the Young's modulus, tensile strength and toughness of the PVA nanocomposite containing 5 wt% hybrid nanofiller (1:2) were significantly improved by 320%, 124% and 159%, respectively; and the elongation at break basically remained compared to the neat PVA matrix. In addition, the glass and melting temperatures as well as the moisture sorption of nanocomposites were also enhanced. This synergistic effect improved the dispersion homogeneity by avoiding the agglomeration phenomenon of nanofillers within the polymer matrix, resulting in nanocomposites with largely enhanced properties compared to those prepared from single nanofiller (CNC or GON). The preparation of these hybrid nanofillers and their incorporation into a polymer provided a novel method for the development of novel multifunctional nanocomposites based on the combination of existing nanomaterials

Nanostructured Na₂CaP₂O₇: A New and Efficient Catalyst for One-Pot Synthesis of 2-Amino-3-Cyanopyridine Derivatives and Evaluation of Their Antibacterial Activity

A facile and novel synthesis of thirteen 2-amino-3-cyanopyridine derivatives 5(a–m) by a one-pot multicomponent reactions (MCRs) is described for the first time, starting from aromatic aldehydes, malononitrile, methyl ketones, or cyclohexanone and ammonium acetate in the presence of the nanostructured diphosphate Na2CaP2O7 (DIPH) at 80 °C under solvent-free conditions. These compounds were brought into existence in a short period with good to outstanding yields (84–94%). The diphosphate Na2CaP2O7 was synthesized and characterized by different techniques (FT-IR, XRD, SEM, and TEM) and used as an efficient, environmentally friendly, easy-to-handle, harmless, secure, and reusable catalyst. Our study was strengthened by combining five new pyrido[2,3-d]pyrimidine derivatives 6(b, c, g, h, j) by intermolecular cyclization of 2-amino-3-cyanopyridines 5(b, c, g, h, j) with formamide. The synthesized products were characterized by FT-IR, 1H NMR, and 13C NMR and by comparing measured melting points with known values reported in the literature. Gas chromatography/mass spectrometry was used to characterize the newly synthesized products and evaluate their purity. The operating conditions were optimized using a model reaction in which the catalyst amount, temperature, time, and solvent effect were evaluated. Antibacterial activity was tested against approved Gram-positive and Gram-negative strains for previously mentioned compounds