A potentiostatic study of the behaviour of Inconel (600) in molar sulphuric acid has been carried out over the temperature range 293-313 K. Values have been established for the potentials and current densities of the corrosion, active-passive transition, passivity and transpassive states. For corrosion, the current density (ic) and potential (Ec) have been determined from well-defined Tafel lines. The potential and current density prior to the commencement of passivity have been obtained corresponding respectively to the critical potential (Ecr( and to the current density (icr) for the active-passive transition state. The passive range was defined by the respective potentials and current densities for passive film formation and dissolution. The dissolution point was correlated with transpassive potential (Et) and current density (it). All the estimated potentials and current densities for the various states were influenced by temperature and the presence of additives in the sulphuric acid. Additives such as nitric acid, thiourea and sodium chloride lowered the corrosion current density (ic) of the alloy while hydrochloric acid enhanced the value of ic. Addition of thiourea or sodium chloride or hydrochloric acid caused a shift in the corrosion potential (Ec) to less negative values while nitric acid shifted Ec to more negative potentials. The kinetic effect of the additives have been studies. Values of activation energy (E) were considered to be apparent and some negative values of E have been obtained with certain additives for the critical and passivity processes. Such negative E values were attributed to small values of true energies of activation together with relatively large exothermic enthalpies of such processes.
Nanoparticles of humic acid and iron oxide were impregnated on the inert sand to produce sorbent for treating groundwater contained of cadmium and copper ions by technology of permeable reactive barrier (PRB). Sewage sludge was the source of the humic acid to prepare the coated sand by humic acid—iron oxide (CSHAIO) sorbent; so, this work is consistent with sustainable development. For 10 mg/L metal concentration, batch tests at speed of 200 rpm signified that the removal efficiencies are greater than 90% at sorbent dosage 0.25 g/ 50 mL, pH 6 and contact time 1 h. The kinetic data was well described by the Pseudo first-order model indicating that physicosorption is the predominant mechanism. The maximum adsorption capacities (qmax) were c
... Show MoreThe Ligand 6,6--(1,2-benzenediazo) bis (3-aminobenzoicacid) derived from o-phenylenediamine and 3-aminobenzoicacid was synthesized. The prepared ligand was identified by Microelemental Analysis, 1HNMR, FT-IR and UV-Vis spectroscopic techniques. Treatment of the ligand with the following metal ions (CoII, NiII, CuII and ZnII ) in aqueous ethanol with a 1:1 M:L ratio and at optimum pH. Characterization of these compounds has been done on the basis of elemental analysis, electronic data, FT-IR and UV-Vis, as well as magnetic susceptibility and conductivity measurements. The nature of the complexes formed were studied following the mole ratio and continuous variation methods, Beer's law obeyed over a concentration range (1×10-4 - 3×10-4 M). H
... Show MoreNew complexes of the type [ML2(H2O)2] ,[FeL2(H2O)Cl] and [VOL2] were M=Co(II),Ni(II) and Cu(II) ,L=4-(2-methyl-4-oxoquinazoline-3(4H)-yl) benzoic acid were synthesized and characterized by element analysis, magnetic susceptibility ,molar conductance ,FT-IR and UV-visible. The studies indicate that the L acts as doubly monodentate bridge for metal ions and form mononuclear complexes. The complexes are found to be octahedral except V(IV) complex is square pyrimde shape . The structural geometries of compounds were also suggested in gas phase by theoretical treatments, using Hyper chem-6 program for the molecular mechanics and semi-empirical calculations, addition heat of formation(?Hf ?) and binding energy (?Eb)for the free ligan
... Show MoreThe search involve the synthesis of some new 1,3-oxazepine and 1,3-diazepine derivatives were synthesized from Schiff base. The Schiff base (VIII) prepared from reaction of aldehyde (IV) derived from L-ascorbic acid with aromatic amine ([2-(4- nitrophenyl)-5-(4-aminophenyl)-1,3,4-oxadiazole] (VII). Oxazepine compounds (IX-XI) were synthesized from the cyclic condensation of Schiff base (VIII) with (maleic, phthalic and 3-nitrophthalic) anhydride, compounds (IX-XI) that were reacted with p-methoxyaniline to give diazepine derivatives (XII-XIV). The structures of the new synthesized compounds have been confirmed by physical properties and spectroscopy measurements such as FTIR, and some of them by 1 H-NMR, 13 CNMR, Mass, and evaluated
... Show MoreThe aim of this work is the synthesis of new Schiff base derived from PVA and Erythro-ascorbic acid derivative (pentulosono-ɣ-lactone-2,3-enedianisoate) and its metal complexes of biological significance. All synthesized compounds were characterized by Thin layer chromatography (TLC) and FTIR spectra and aldehyde was also characterized by (U.V-Vis), 1HNMR, 13CNMR and mass spectra. The synthesized Schiff base & its metal complexes were screened for their in vitro antimicrobial activity against five pathogenic bacteria (Escherichia coli, Shigella dysentery,Klebsiellapneumonae,Staphylococcusaureus, Staphylococcus Albus) and two fungal (Aspergillus Niger,Yeast).The biological activity ofall complexes is higher than free Schiff base ligand andf
... Show MoreThe study was planned to evaluate the effect of adding Guanidinoacetic acid in some characteristics of the sperm of the rams. This study was conducted in the animal field of the Animal Production Department / Faculty of Agricultural Engineering Sciences / University of Baghdad, for the period from 5/8/2018 to 28/2/2019. In this experiment, 3 rams were used at the age of 2-2.5 years and weighed 50-54 kg. The semen was collected early in the morning and once a week and the semen was pooled to remove the individual differences. The treatments were divided: GAA-free control group, treatment T1 (0.05 mg / 100 ml GAA), T2 treatment (0.1 mg / 100 ml GAA) and T3 treatment (0.2 mg / 100 ml GAA). The results of the study showed a significant decrease
... Show MoreMany condensed polymers [A1-A7] were prepared via reaction of (Ethylenediaminetetraacetic acid = EDTA), with different prepared imide-diamines by modification [ modification of amino acids and antibiotics (B1- B7)] Imide-diamines were prepared by chlorination of L-amino acids such as [ L-Histidine, L-Alanine, L-Valine, L-Glycine and L-Aspargine ] or selected antibiotics such as [Cephallixine monohydrate and Amoxilline ] with thionyl chloride at 0°C, then reacted with ammonia to obtain imidediamines [B1-B7] . The physical properties of all prepared condensed polymers [A1-A7], new prepared diamines [B1-B7] were studied and characterized by FT -IR spectroscope to certify the structural formulas. The thermal analysis (TGA, DTA) were studied, a
... Show MoreThe purpose of this research work is to synthesize conjugates of NSAIDs (ibuprofen, and naproxen) with sulfadiazine as possible mutual prodrugs to overcome the local gastric irritation of NSAIDs with free carboxyl group by formation of ester linkage that supposed to remain intact in stomach and may hydrolyze in intestine chemically or enzymatically; in addition to that attempting to target the synthesized derivative to the colon by formation of azo bond that undergo reduction only by colonic bacterial azoreductaze enzyme to liberate the parent compound to act locally (treatment of inflammation and infections in colon)