Investigation of Agricultural Waste as Economical and Effective Bio-Inhibitors for Inhibiting Scaling in Natural Hard Water

In this study, agricultural waste was utilized as new bio-inhibitors to prevent scale formation in hard waters. Aqueous extracts of strawberry and tomato leaves were utilized for reducing the scale deposits formed on metallic surfaces by Bounouara ground hard water, which supplies Constantine city in Algeria. Anti-scaling properties were evaluated by chronoamperometry and impedancemetry techniques. The effect of temperature and concentration on the efficiency of the bio-inhibitors was assessed. The results showed that the anti-scaling effect of strawberry leaf extracts started at the very low concentration of 1 ppm, with 31% efficiency, reaching complete scaling inhibition at 15 ppm (20ºC), whereas the inhibitory effect of tomato leaf extracts was noticed at 2.5 ppm, with 36% efficiency, and total inhibition at 20 ppm (20ºC). The efficiency of strawberry and tomato leaf extracts at 40∘C was also confirmed, although total inhibition was attained at a higher concentration. Keywords: hard water, agricultural waste, strawberry leaves, tomato leaves, bioinhibitors, scaling inhibitio

Hydrogen recovery from big-scale porous metal hydride (MH) reactor: impact of pressure and MH-thermophysical properties

An advanced ANSYS FLUENT-based model was developed for hydrogen recovery from a multi-tubular fixed-bed metal hydride (MH) reactor of large-scale design. The model was firstly validated by comparing its results to specific experimental data. Mass and heat transfer processes inside the fixed bed were investigated for various pressures and thermochemical characteristics of the MH (thermal conductivity, porosity and reaction parameters). The findings were reported as average, local and spatial changes in the metal’s bed temperature and hydrogen content. During the initial stage of the endothermic desorption (t<100 s), the bed temperature dropped dramatically in all cases . During this time, there was a massive emission of hydrogen. The bed temperature was then raised due to the reactor’s external convective heating, while the hydrogen release continued until the MH was completely dehydrided. The dehydrogenation rate of the MH was enhanced when the discharge pressure was raised. Furthermore, some other characteristics of the MH, i.e., porosity, thermal conductivity, desorption rate constant and activation energy, significantly impacted the resulting mass and heat fluxes inside the bed material

Methyl 3-(Quinolin-2-yl)indolizine-1-carboxylate

A novel compound, methyl 3-(quinolin-2-yl)indolizine-1-carboxylate (2) has been synthesized by cycloaddition reaction of 1-(quinolin-2-ylmethyl)pyridinium ylide (1) with methyl propiolate in presence of sodium hydride in THF. The structure of this compound was established by IR, 1H-NMR, 13C-NMR and MS dat

Crystal structure of 13-(2-methoxyphenyl)-3,4-dihydro-2H-indazolo[1,2-b]phthalazine-1,6,11(13H)-trione

In the title compound, C22H18N2O4, the three fused rings of the pyrazolophthalazine moiety are coplanar (r.m.s. deviation = 0.027 Å). The cyclohexene ring fused to the pyrazolidine ring, so forming the indazolophthalazine unit, has a half-chair conformation. The benzene ring is almost normal to the mean plane of the pyrazolophthalazine moiety, with a dihedral angle of 87.21 (6)° between their planes. In the crystal, molecules are linked by pairs of C—H...O hydrogen bonds forming inversion dimers. The dimers are linked via C—H...π interactions, forming slabs parallel to (100). Between the slabs there are weak π–π interactions [shortest inter-centroid distance = 3.6664 (9) Å], leading to the formation of a three-dimensional structure

Melting/solidification of phase change material in a multi-tube heat exchanger in the presence of metal foam: effect of the geometrical configuration of tubes

One of the likely methods for enhancing heat transfer in a latent thermal energy storage system is the conception of a thermal unit. In this study, the orientation of oval tubes (horizontal, vertical, and oblique) in phase change material (PCM, C19-C20)-based shell-tube heat exchanger was analyzed with respect to the metal foam (MF) type (graphite, copper, and nickel) in comparison to the case of pure PCM. For this purpose, a two-dimensional mathematical model was developed to investigate the thermal efficiency of the PCM-metal foam based composite energy storage unit. It was concluded that the orientation of the oval tubes (oblique, horizontal, and vertical) has a negligible impact on the performance of the thermal unit during the melting/solidification processes. Based on the liquid/solid fraction, total enthalpy and the average temperature in the annular space, the performance of a heat exchanger during fusion/solidification periods is in the order: copper-MF > graphite-MF > nickel-MF > pure PCM. Whatever the adopted MF or the geometry of tubes, the melting process is expedited compared to the solidification mechanism

2-Hydroxymethyl-1,3-dimethyl-1H-imidazol-3-ium triiodide

The crystal packing of the title salt, C6H11N2O+&#183;I3&#8722;, can be described as consisting of alternating layers of cations and anions parallel to the (100) plane along the a-axis direction. The components are linked by O&#8212;H...I, C&#8212;H...I and C&#8212;H...O interactions, generating a three-dimensional network. The O atom deviates from the imidazol ring by 0.896&#8197;(2)&#8197;&#197;

2-Hydroxymethyl-1,3-dimethyl-1H-benzimidazol-3-ium iodide

In the cation of the title compound, C10H13N2O+&#183;I&#8722;, all non-H atoms, with the exception of the O atom, are essentially coplanar, with a maximum deviation of 0.04&#8197;(1)&#8197;&#197;. In the crystal, the cations and anions are arranged in layers parallel to (100). The cations are connected to the anions via an O&#8212;H...I hydrogen bond and there are significant &#960;&#8211;&#960; stacking interactions between cation layers, with centroid&#8211;centroid distances in the range 3.606&#8197;(5)&#8211;3.630&#8197;(5)&#8197;&#197;. A weak intramolecular C&#8212;H...O hydrogen bond is also observed. The crystal studied was an inversion twin with refined components of 0.52&#8197;(5) and 0.48&#8197;(5)

Crystal structure of 13-phenyl-2,3,4,13-tetrahydro-1H-indazolo[1,2-b]phthalazine-1,6,11-trione

The title compound, C21H16N2O3, consists of an indazolone moiety, bearing a phenyl group, fused to a phthalazine ring system (r.m.s. deviation = 0.018 Å). The phenyl ring is almost normal to the mean plane of the five-membered ring of the indazolone moiety, making a dihedral angle of 89.64 (7)°. The six-membered ring of the indazolone moiety has an envelope conformation, with the central methylene C atom as the flap. In the crystal, molecules are linked via C—H...O hydrogen bonds, forming slabs parallel to the bc plane. The slabs are linked via C—H...π and π–π interactions [the shortest inter-centroid distance involving rings of pyrazolophthalazine moieties is 3.6430 (8) Å], forming a three-dimensional structure

Three metal(II) complexes constructed using the 2-(1H-benzo[d]imidazol-2-yl)quinoline ligand

International audience2-(1H-benzo[d]imidazol-2-yl)quinoline (BQ) as ligand and three coordination compounds of formula {Zn(BQ)Cl-2} (1), {Pb(BQ)Cl-2} n (2) and {[Cu(BQ)(2)(OC(O)CH3)] OC(O)CH3 center dot CH3COOH} (3) have been synthesized and fully characterized. The complexes crystallize in triclinic space group P1. In complexes 1 and 2, the coordination geometry is a distorted tetrahedral environment around the zinc center and a distorted sixfold coordination geometry around the lead center, respectively. In complex 3 the central Cu(II) center is in a trigonal bipyramidal coordination geometry. The Cu(II) ion is surrounded by two bidentate 2-(2'-quinolyl) benzimidazole (BQ) ligands and one coordinated acetate molecule. One further acetate anion associated by a strong hydrogen bond with a molecule of acetic acid balances the charge of the compound