Molar conductivity of ascorbic acid (AA) with some α–amino acids (glycine (Gly), methionine (Met), cysteine (Cys) and tryptophan (Trp)) in aqueous solution was measured at range temperatures from 298 K to 313 K. Λo. The limiting molar conductivity, KA, the association constant was calculated using the Shedlovsky method, and R, the association distance calculated by Stokes–Einstein equation. The thermodynamic parameters (The heat of association ΔHo, the change in Gibbs free energy ΔGo, the change of entropy ΔSo), and (ΔES), the activation energy were also calculated. All of the results obtained were discussed. The data showed the increasing in Λo, with the increasing of temperature. The positive values for (ΔSo) and (ΔES) showed a decrease in solvation of ion–pair and signifying the higher mobility of the ions. The negative value of ΔHo, refers that the association processes are exothermic. The negative values of ΔGo, are for ion association in aqueous solution and increase with the increase in temperature.
Abstract. Geographical and remote sensing, which gave a picture of the change in the area of agricultural land in the study area for selected years (1980, 1990, 2000, 2010, 2020). In particular and Iraq in general, as this led to a reduction in the areas of agricultural lands and in return an increase in arid lands and their desertifica- tion and the loss of their productive value, which as a result leads to the migration of the population, the change of land sex, the failure to achieve food security and dependence on the import of the food basket.
In this study, a low-cost biosorbent, dead mushroom biomass (DMB) granules, was used for investigating the optimum conditions of Pb(II), Cu(II), and Ni(II) biosorption from aqueous solutions. Various physicochemical parameters, such as initial metal ion concentration, equilibrium time, pH value, agitation speed, particles diameter, and adsorbent dosage, were studied. Five mathematical models describing the biosorption equilibrium and isotherm constants were tested to find the maximum uptake capacities: Langmuir, Freundlich, Redlich-Peterson, Sips, and Khan models. The best fit to the Pb(II) and Ni(II) biosorption results was obtained by Langmuir model with maximum uptake capacities of 44.67 and 29.17 mg/g for these two ions, respectively, w
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ABSTRACT. A new three metal complexes of La(III), Ce(IV) and UO2(II) ions have been synthesized based on a Schiff base derived from the condensation of L-histidine and anisaldehyde. All prepared compounds were characterized by different spectroscopic techniques and Density-functional theory (DFT) calculations. The complexes were proposed to have an octahedral structure based on the investigated results. The optimized shape, numbering system, and dipole moment vector of Ligand and La, Ce, and UO2 (1:1) chelates were investigated. The Schiff base ligand and complexes exhibit moderate action against all of the bacteria tested, with P. aeruginosa, Klebsiella sp., and E. faecalis respectively being the order of inhibition.
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Reducing of ethyl 4-((2-hydroxy-3-methoxybenzylidene)amino)benzoate (1) afford ethyl 4-((2-hydroxy-3-methoxybenzyl) amino)benzoate (2). Reaction of this compound with Vilsmeier reagent affords novel 2-chloro-[1,3] benzoxazine ring (3). The corresponding acid hydrazide of compound 3 was synthesized from reaction of compound (3) with hydrazine hydrate. Newly series of hydrazones(5a–i) were synthesized from reaction of acid hydrazide with various aryl aldehydes. Antibacterial activity of the hydrazones wassecerned utilizing gram-negative and gram-positive bacteria. Compound (5b) and (5c) exhibited significant antibacterial ability against both gram-negative and gram-positive bacteria, while the compounds(5a) showed mild antibacterial activit
... Show MoreA phytoremediation experiment was carried out with kerosene as a model for total petroleum hydrocarbons. A constructed wetland of barley was exposed to kerosene pollutants at varying concentrations (1, 2, and 3% v/v) in a subsurface flow (SSF) system. After a period of 42 days of exposure, it was found that the average ability to eliminate kerosene ranged from 56.5% to 61.2%, with the highest removal obtained at a kerosene concentration of 1% v/v. The analysis of kerosene at varying initial concentrations allowed the kinetics of kerosene to be fitted with the Grau model, which was closer than that with the zero order, first order, or second order kinetic models. The experimental study showed that the barley plant designed in a subsu
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Newly 4-amino-1,2,4-triazole-3-thione ring 2 was formed at position six of 2-methylphenol from the reaction of 6-(5-thio1,3,4-oxadiazol-2-yl)-2-methylphenol 1 with hydrazine hydrochloride in the presence of anhydrase sodium acetate. Seven newly fused heterocyclic compounds were synthesized from compound 2. First fused heterocyclic was 6-(6-(3,5-di-tertbutyl-4-hydroxyphenyl)-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazol-3-yl)-2-methylphenol 3 synthesized from reaction compound 2 with 3,5-di-tert-butyl-4-hydroxybenzoic acid in POCl3. Reaction compound 2 with bromophencylbromide afford 6-(6-(4-bromophenyl)-5H-[1,2,4]triazolo[3,4-b][1,3,4]-thiadiazin-3-yl)-2-methylphenol 4. 6-(6-thio-1,7a-dihydro-[1,2,4] triazolo[3,4-b][1,3,4]-thiadiazol-3-yl)-2
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