Applied Chemistry

Gum Arabic exudate was collected from Acacia Senegal trees around Zaria metropolis. The gum was hydrated in double strength chloroform water, purified in 95% ethanol and then washed with diethyl ether. Modification of the gum was performed with ethanol and Acetic anhydride. Densities of the samples were compared with that of the unmodified gum and it was found that both samples were less dense than the unmodified gum. From turbidity measurement, ethanol modified (EGL) gum appears more turbid than both acetic anhydride modification (AAN) and unmodified gum (PGM). In salinity, conductivity and TDS tests, AAN sample higher values than other samples. The melting point of EGL and PGM are only slightly different, 242oC and 245oC respectively while that of AAN was 229oC. The mechanical properties of the samples were measured using Honsfield Tensometer. The AAN sample has the highest modulus at 10, 20, 30 and 40% gum composition. For PGM the modulus drops from 10-30% gum composition then finally increases. The ACT modification shows decrease in modulus as the percent of gum increases. Modulus of PGM drops at 20, 40, 60 and 80% gum composition. It was found that the tensile strength of the chemical modification formulations reinforced the PVC matrix at 10%/90%, 20%/80% and 30%/70% gum/PVC compositions for AAN and at 10%/90% and 20%/80% gum/PVC compositions. Though EGL showed increase at 30%/70% composition, its tensile strength is similar to that of the unmodified gum (PGM), decreasing with increasing gum concentration.

A selective method for the fast determination of trace amounts of Pb (II)ions in water samples has been developed. method has been developed for preconcentration of Pb on organic-solution-processable functionalized-nano graphene (SPFGraphene) adsorben in the pH range 5.0–10.0, prior to its spectrophotometric determination, based on the oxidation of bromopyrogallol red at ? = 517 nm. This method makes it possible to quantitize Pb in the range of 4.2×10?9 to 2.3×10?5 M, with a detection limit (S/N = 3) of 1.42×10?9 M. This procedure has been successfully applied to determine the ultra trace levels of Pb in the environmental samples, free from the interference of some diverse ions. The precision, expressed as relative standard deviation of three measurements is better than 3.0%.

Sediment and fish (nile Tilapia, Oreochromis niloticus) were collected from six sites of Lake Hawassa namely; Tikur Wuha, Amora Gedel, Dorie Bafana, Central part of the lake, the opposite side of Amora Gedel and Referral Hospital sites. Concentration of heavy metals was analyzed quantitatively using Flame Atomic Absorption Spectrophotometer and Chemometric methods. The maximum and minimum mean levels (mg/kg dry mass) in different lake sediment sites were Cu (51.38-17.64), Mn (348.51-140.63), Cd (12.8764-403), Pb (30.05-6.72), Ni (26.73-8.43 ), Zn (367.84-147.49), Cr (14.15-5.34), Co (27.19-9.59 ), Mg (3859.86-1872.43), Na (4913.72-2903.043), Ca (5526.74 - 3608.71), K (4229.69-2255.57) and that of fish muscle were Cu (13.833-5.666), Mn (11.972-9.722), Zn (21.110-12.055), Ca (574-482), Mg (512-437), Na (771-681), K (903-785). The result shows that the metal concentration in sediment samples is in order of Ca > Na > K > Mg > Zn > Mn > Cu > Pb > Co > Ni > Cr > Cd. The detectable metals in Tilapia fish muscle were in order of K > Na > Ca > Mg > Zn > Mn > Cu. In all the samples, concentrations of metals in sediment samples were higher than those of fish samples.

This study was aimed at determining the uptake of heavy metals (Cd, Pb, Ni, Fe and Zn) by plant (Talinum triangulare) if cultivated at some waste dumpsites in Uyo metropolis. Soil samples were taken within 0-15cm and plant samples were collected in triplicate and analysed using Atomic Absorption Spectrophotometer (AAS). Mean results obtained from the soil and plant samples indicated Fe to have the highest concentration (216.29±29.15mg/kg and 243.339±12.622mg/kg respectively) which is significantly higher than its control (124.00mg/kg and 78.375mg/kg respectively). Concentration of Pb in both dumpsite soil and plant samples were below detectable limit. These results when compared with the acceptable standard revealed that all the metal levels in both soil and plant samples were within the acceptable limits accept Cd in soil sample. Transfer factor for Fe was 1.13, while others were below 1. All the metals showed positive relationship except Cd (-0.60).

The ultrasonic velocity, density and viscosity have been measured for the binary liquid mixture of Cord liver oil + aniline as a function of different composition (0.2%,0.4%,0.6%,0.8% and 1%) and different temperatures such as 303,308,313,318and 323K. The experimental data has been used to calculate some excess parameters namely, adiabatic compressibility (?), intermolecular free length (Lf), free volume (Vf), internal pressure (?i), relaxation time (?), absorption coefficient (?/f¬¬2) and relative association (RA). The results are discussed and interpreted about structural and specific interactions that predominated by hydrogen bonding.

The title compound has been prepared in high yield from 9-benzyl-purine derivative by reaction with diethoxymethyl acetate (DEMA). The structure of the tricyclic compound, 7-(2-chlorobenzyl-3H-[1,2,4]triazolo[3,1-i]purine 2, was confirmed by X-ray analysis. Semiempirical calculations for predicting geometrical parameters are in excellent agreement with the X-ray crystal structure.

Imidazoles and formimidoyl-1H-imidazoles derivatives were prepared by reaction between formamidines and weak or strong base depending on reaction conditions in good yields. All these derivatives have been fully characterized by spectroscopic data.

The present investigation was undertaken to study of Cauvery river water at ten different locations in Namakkal district, Tamilnadu, India. The water samples were collected from different places and analyzed for various water quality parameters like Appearance, Adour, Turbidity, pH, EC, TDS, Total alkalinity, Total hardness, Calcium, Magnesium, Sodium, Potassium, Iron, Manganese, Ammonia, Nitrite, Chloride, Fluoride, Sulphate, Phosphate, Tidy’s, Dissolved oxygen, Biological oxygen demand, Chemical oxygen demand. The water quality parameters are analyzed after biomass treatment using vetiveria Zizanoides. Water quality parameters were compared WHO, USPH, BIS

This research was built to investigate the main role of phosphorylated sol-gel (PSG) to reduce the ignition problems of polyester fabric. Thermogravimetric analysis (TGA), Differential Scanning Calorimeter (DSC) and Fourier transform infrared spectroscopy (FTIR) of the un-treated and treated samples were investigated. PSG material was played as protective shielding coat and improved the thermal behavior. FTIR analysis of the treated sample showed that there is a sort of interaction between the molecules of PSG and the fabric. Limiting oxygen index (LOI) for the lowest oxygen concentration needed to start the ignition showed also an improvement in the ignition retarding behavior due to this treatment. To increase the affinity of fibers towards PSG, the fabric surface was exposed to UV/Ozone for different periods. Exposuring samples for 90 min showed the best results comparing to other samples (irradiated for UV/Ozone for 0, 30 and 125 min). Ignition behavior (UL/94) was also applied on samples by using the flame chamber for determining the rate of burning. The results of UL/94 (according to ISO 3795) confirmed the ignition behavior results produced from the LOI

The dispersion of bioactive glass, (BG), sample was studied using cetyltrimethylammonium bromide (CTAB). An array of experimental techniques like adsorption, zeta potential and turbidity were used to achieve this goal. Turbidity was used as a parameter to reflect the degree of dispersion where a higher value of turbidity represents higher dispersion efficiency. Dispersion of the BG particles was largely affected by CTAB concentration and the solution pH. Dispersion of the BG particles was increased with increasing of CTAB concentration till the CMC of CTAB is reached. Beyond the CMC , the BG particles become hydrophilic causing a decrease in glass dispersion. On the other hand, dispersion of the BG particles was affected with the solution pH. It was increased with increasing pH till pH 9. At higher pH, dispersion was decreased where the formation of micelles is favored.