Applied Chemistry

The inhibition efficiency of coffee husk extract and extract of Ziziphusspina Christi on the corrosion of aluminum in 0.5 M NaOH solutions was investigated using weight loss method at 25 and 45°C. Surface was examined using energy dispersive X-ray analysis (EDX), and scanning electron microscopy (SEM). Experimental investigations showed that coffee husk extract and Ziziphusspina Christi extract reduce the corrosion of aluminum in 0.5M NaOH solutions. The inhibition mechanism was deduced from the temperature dependence of the inhibition efficiency as well as from activation parameters that govern the process. The adsorption of two extracts on the aluminum surface was found to obey Langmuir, Temkin and thermodynamic/kinetic model of adsorption isotherms. The obtained results are consistent with physisorption adsorption.

In this study all the four basins of Dal lake were studied for various physico-chemical parameters in all the seasons and the eight different vegetable gardens falling within the Dal Lake area were selected to study their impact on the water quality of the Dal. The various parameters were analysed and accordingly measures were suggested to restore the quality of Dal.

Setting a conventional cement plug is nearly unsuccessful when there is any wellbore flow especially for the zechstein formations. As such, the used of sodium silicate remain the common option. The silicate polymerization and gelation has been used in well formation to plug holes and reduce the catastrophic flow which cause a lot of production looses. This is usually encountered during drilling rocks zone producing large amount of water or brine. This could result in large volume of the drilling fluid lost into the formation and consequently reduce the effectiveness of the drilling operations. A well designed silicate/cement material forms an impermeable plug and reduces the adverse of the flow also the in-situ gelation of the process is better understood when the chemistry of the process and the chemical evolution of the brine formation is given due consideration.

Copper (II) phthalocyanine and 2, 9, 16, 23 tetrakis nitro copper (II) phthalocyanine  has been synthesized respectively from phthalonitrile and 4-nitro phthalonitrile under solvent-free condition using two different catalysts. 4-Nitro phthalonitrile synthesized from phthalimide in three steps. The reaction time of ruthenium chloride and HZSM-5 catalysts was very shorter than ammonium molybdate and H? catalysts. The yield while we used ruthenium chloride and HZSM-5 catalysts were very higher than another. The newly prepared compound has been characterized by IR, UV-Vis, ¹HNMR and XRD spectra.

Studies on synthesis, characterization, antimicrobial and antioxidant properties of some metal(II) complexes of the mixed ligands, Vitamins B2 (Riboflavin, HL) and Benzoic acid (HL2), where M = Mn, Fe, Co, Ni, Cu and Zn were carried out. The conductivity measurements and percentage metal analysis confirmed that the metal complexes were covalent in DMS with the formulations [M(HL)(HL1)Cl2] and [M(HL)(HL1)SO4]. The room temperature magnetic moments and electronic spectra measurements were corroborative of 6-coordinate, octahedral geometry for all the metal complexes. In addition, the Fe(II), Co(II) and Ni(II) complexes exhibited spin-crossover, the Mn(II) and Cu(II) complexes were dimeric and the Zn(II) complex was mononuclear. The infrared spectra data showed that the coordination in the metal complexes occurred through the hydroxy oxygen atoms in Riboflavin, and the carboxylate oxygen atoms in Benzoic acid. The antimicrobial screening of the metal complexes against Escherichia coli, Proteus spp, Streptococcus pyogenes, Candida albicans, Salmonella sp, Streptococcus sp, Bacillus spp, Staphylococcus sp and Pseudomonas spp revealed that the Co(II) complex had the best activity with inhibitory zones range of 7.0-20.0 mm. The antioxidant screening of the metal complexes showed that [Cu(HL)(HL2)Cl2] had the best activity with percentage inhibition of about 50.0 which was about twice that of the standards, Ascorbic acid and ?-tocopherol, proving its potentials as an anticancer agent.

Proximate, amino acids and fatty acids compositions of the leaves, stem and root were determined in Moringa oleifera. The proximate composition was determined in fresh samples while other parameters were determined on dry weight basis. Both crude protein and total ash followed the trend of (g/100 g): leaves > root > stem but the soluble carbohydrate had a trend of root > stem > leaves. Leaves had the highest level of total amino acids (76.4 g/100 g) and followed by the root (70.9 g/100 g) while stem had 65.4 g/100 g. For the EAA, it was 35.4 g/100 g (leaves) > 28.4 g/100 g (root) > 26.3 g/100 g (stem). The total sulphur amino acid was generally low at 2.81-3.06 g/100 g but the % Cys in TSAA was slightly high at 48.5-51.6 %. In the amino acids scores, the following amino acids had scores greater than 1.0 in comparison with whole hen’s egg: Gly (1.56-1.97), Glu (1.15-1.28), and Cys (1.14-1.16) whereas Met was the limiting amino acid in each of the three samples with values of 0.31 (leaves), 0.23 (stem) and 0.30 (root); in the pre-school children requirements, these amino acids had scores greater than 1.0: Met + Cys (1.12-1.22), Phe + Tyr (1.04-1.11) and His (1.02-1.08) whereas Lys was the limiting amino acid with values of 0.57 (leaves), 0.64 (stem) and 0.63 (root); on the provisional amino acid scoring pattern, only Phe + Tyr had scores greater than 1.0: Phe + Tyr (1.17, leaves), 1.09 (stem) and 1.10 (root), Val was the limiting amino acid here: 0.63 (leaves), 0.62 (stem) and 0.69 (root). P-PER had values of 1.60-1.72 and EAAI had values of 0.86-0.93. The samples were basically acidic with pI values of 5.4 to 5.8. The most concentrated fatty acid was SFA with values of (%): 97.5 (stem) > 58.0 (leaves) > 53.8 (root). Predominant MUFA was in root with a trend of (%): 38.7 (root) > 4.61 (leaves) > 1.00 (stem) and in PUFA, trend was 37.4 (leaves) > 7.54 (root) > 1.20 (stem). Under the fatty acid parameters, leaves were best in 4/6 (66.7 %) in EPSI, PUFA, PUFA/SFA and MUFA + PUFA whereas root was best in 2/6 (33.3 %) in LA/ALA and MUFA/SFA.

Sodium montmorillonite clay was successfully modified by double modification one organic modification and the other inorganic phosphate. The nanodispersion was proven by transmission electron microscope which showed mixed morphology (intercalated, exfoliated and immiscible structures) in polymer matrix. In general, the thermal stability and flammability properties were improved by loading high density polyethylene by double modified clay.

Dihydro-3,4-dihydroxy-5-(hydroxymethyl)furan-2(3H)-one has been prepared in two steps from galactose. The first step potassium-2,3,4,5-tetrahedroxypentanoate was obtained in 64% yield and the title compound has been isolated in next step with 75% yield. The structures of the products were characterized by IR, 1H, 13C, mass and microanalysis study.

Some metal(II) complexes of mixed ligands-dimethydithiocarbamic and p-aminobenzoic acids were synthesized (M = Mn, Fe, Co, Ni, Cu and Zn) and characterized by solubility, percentage metal, conductivity, infrared and electronic spectra measurements. Infrared data showed that the dimethydithiocarbamic and p-aminobenzoic acids coordinated through the sulphur atoms, and the carboxylate oxygen atoms to the metal atoms respectively. Electronic spectra and room temperature magnetic moments corroborated equilibrium between high spin and low spin octahedral geometry (spin-crossover) for the Mn(II), Fe(II), Ni(II) and Co(II) complexes, while the Cu(II) and Zn(II) complexes were octahedral and mononuclear. The antimicrobial activities of the metal complexes against Escherichia spp, Streptococcus spp, Proteus sp, Candida sp, Salmonella sp, Bacillus spp, Staphylococcus sp and Pseudomonas spp showed that the Mn(II), Fe(II) and Zn(II) complexes had very good antimicrobial activities against these microbes with inhibitory zones range of 7.0-20.0, 7.0-20.0 and 9.0-27.0 mm respectively, just like Streptomycin (7.0-29.0 mm) proving their potentials as broad-spectrum antimicrobial agents in-vitro.

Density, Viscosity and Ultrasound velocity of Tetra ethyl lead in aqueous NaOH and aqueous KOH have been measured at varying concentrations at 30oC. The derived acoustic parameters like specific acoustic impedance (Z), intermolecular free length (Lf), relative association (Ra), isentropic compressibility (?s) etc. have been calculated using density, viscosity and ultrasound velocity data. These parameters are used to discuss the nature and extent of intermolecular interactions in the mixture.