Table of Contents - Volume 3 Number 2

An efficient procedure for pre-concentration, separation and determination of the trace amounts of lead (II) ions in water samples has been established. The analyte is adsorbed on the surface of C18 silica membrane disk modified with APDC, quantitatively, while other interfering ions pass through the disk to drain. The sorbed Pb2+ ions are then stripped by appropriate eluting agents followed by monitoring of the eluates by flame atomic absorption spectrometry (FAAS). The effects of sample pH, amount of the modifier, stripping agent types, sample flow-rates, and potential interfering ions were also investigated. The described method involves a pre-concentration factor of about 200. The detection limit of the procedure is 0.93 ng.mL-1. The method was employed for isolation and determination of lead in different water samples.

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The inhibition effect of Ammi majus L. fruit extracts, alcoholic extract (A), aqueous extract (B) and defatting extract (C), on the corrosion of mild steel in 2.0M H2SO4 containing 10% EtOH at 30?C was investigated using chemical, electrochemical and scanning microscopy measurements. It was found that as the concentration of extracts increases, the rate of mild steel corrosion is decreased, which indicates that an inhibition of the corrosion process take place. The decrease of the inhibition efficiency of the extracts was given as: B > C > A, the electrochemical results showed that the extracts A, B and C, act as mixed inhibitors and the corrosion inhibition of mild steel occurred mainly by charge transfer mechanism. The scanning electron microscopy results showed that the changes (pits) on the mild steel surface is due to the effect of acid corrosion became less, the steel surface appears to be unchanged , by the extracts addition. The experimental results fit Langmuir isotherm. Values of equilibrium constant of adsorption Kads. and the standard free energies of adsorption DG?ads. for the extracts, were calculated. The effect of two coumarin compounds was studied by chemical methods in 2.0M H2SO4 containing 10% EtOH separately and in mixture of them. The results showed that: ? As the concentration of studied compounds (Xabthotoxin(I), Imperatorin (II) increased, the rate of mild steel corrosion was decreased. ? The inhibition efficency obtained from the mixture was very high and nearly the same as when the extract was used which supported that the inhibition of A. majus extract is due to the presence of coumarin compounds.

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Attempts were made to investigate compositional constraints in the synthesis of 4A molecular sieves using metakaolin from the gel composition Al2O3: 7.1SiO2: 5.8 Na2O: 150 H2O in the temperature 100oC for 6-8h. Use of other clay materials in 4A synthesis is nullified. XRD and FT-IR spectra in framework region of 4A synthesized using metakaolin in autogeneous pressure are having similar pattern to the reported one. Scanning electron microscopic picture of the both are varies kaolin and 4A varies. MASNMR shows the presence of tetrahedral aluminium and Si:4Al, Si:3Al:Si and Si:4Si species.

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A novel and selective method for the fast determination of trace amounts of chromium species in water samples has been developed. The procedure is based on the selective formation of chromium diethyldithiocarbamate complexes at different pH in the presence of Mn(II) as an enhancement agent of chromium signals followed by elution with organic eluents and determination by atomic absorption spectrometry. The maximum capacity of the employed disks was found to be 396 ± 3 μg and 376 ± 2 μg for Cr(III) and Cr(VI), respectively. The detection limit of the proposed method is 49 and 43 ng.L-1 for Cr(III) and Cr(VI), respectively. The proposed method was successfully applied for determination of Cr(III) and Cr(VI) in different water samples.

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Use of Jigs and fixtures can guarantee the proper fixation and positioning of cutting tools with respect to work piece during the entire manufacturing process, helping in manufacturing of identical parts at required accuracy and production speed. In this paper, parametric modelling of a jig and fixture for drilling a cylindrical part, with mounting surface perpendicular to the cutting tool, has been carried out in CAE. The stability condition of the work piece during the drilling process has been evaluated by studying the forces due to the cutting tool and the clamp on the work piece, using the built-in FEM tools. The plastic deformation of the work piece must be prevented, and the elastic deformation should be such that it does not cause separation of the work piece from the positioner. Results show the high potential of the software in such design and modelling practices. A static analysis of the work piece secured in a jig and fixture has been performed to obtain the applied loads accurately and quickly. This helps prevent the extra cost incurred due to improper design.

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New synthesis route using metal carboxylates precursor method was adopted for the synthesis of NiFe2O3 is reported. X-ray density, Tap density and powder densities of as prepared NiFe2O3 are calculated. The as synthesized NiO, Fe2O3 and NiFe2O3 are characterized by X-ray diffraction (XRD) technique. Infrared spectroscopic (IR) technique was used to know the formation of M-O and M-M bonds in prepared oxide materials.

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Accurate measurements and the associated instrumentation play vital role in the development of different industries. It is generally accepted that without special purpose measuring instruments, it would be impossible to repeat the work done by another individual in any field of research. Application of gauges as a substitute for the direct measurement methods can significantly enhance the manufactured parts verification process, both in terms of speed with which the process is performed, and also the desired accuracy with which the process must be done. On the other hand, the direct transfer of measurement data from the gauge to computer can further improve and reduce the tedious process of Statistical Process Control (SPC). To fulfil the above goals, we have used CAD software to perform a feasibility study for the design and modelling of various modular bore gauge mechanisms, considering the requirements of a precise measurement instrument. We studied several mechanisms, and selected the best mechanism for this purpose. Using FEM tools, a fatigue analysis was then performed to analyze a critical part in the instrument, which experiences the maximum fatigue due to continuous operation. The life cycle calculations for this critical part show that our design and analysis process has been satisfactory, and that the method can be used for the design of precise modular bore gauges.

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The solublization of 2-hydroxy-3-naphthoic acid (2-H-3-NA) solubilizate into the micellar core of certain surfactants has been studied with the help of fluorescence spectroscopy. The various surfactants used for the study are nonionic as well as ionic ones. The nonionic surfactants are TX-100 and Brij-35 the anionics are DBSS and DSSS and two of the cationic surfactants are CPC and CTAB. The fluorescene peak height enhanced gradually on increasing the nonionic surfactant concentration, reaching to a limiting value with no shift in the peak position. A red shift occurred in the emission maxima in cationic surfactant media. The solubilization phenomenon was also confirmed by absorption spectral studies and light scattering measurements. Quantum yield measurements were made in these micellar media at different concentrations using anthracene as fluorescenece standard. Calculations were done for stokes? shift of 2-H-3-NA at different concentrations. The calculated results are in fair agreement with the experimental results. Environmental studies of the effect of nonaqueous solvent ethanol on the fluorescence spectra of the 2-H-3-NA compound were made. On increasing the ethanol concentration the fluorescence emission maxima showed enhancemant reaching a limiting value at its higher concentration. Thus, an understanding of the process of solubilization is expected to helps understanding the interplay of the different favourable and unfavourable forces guiding micellization.

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The fluorescence properties of an anionic dye, mercurochrome (of xanthene series) solubilized in the surfactant micelles in aqueous media is studies with the help of fluorescence spectroscopy. The fluorescence peak height at 530 nm decreases on increasing the concentration of surfactant reaching a limiting value. At room temperature emission of mercurochrome in surfactant micelles shows a significant, red shifts compared with that in pure water. Quantum yield measurements were also made at different concentration of the surfactants, using anthracene as the standards. Stokes shift was also measured at different concentration of the solutions. The decrease in flouroscence intensity is due to interaction between the surfactant micelles and the dye molecules which cause the aggregationof monomeric form of the dye molecules into its dimeric or polymeric form. The result has been attributed to micelle formation action of surfactants and the dye surfactants interactions.

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This paper unveils a measure of risk management through waste minimization from recycling process of a hazardous waste. Lead-based slag from Exide Battery Nigeria Limited, Ibadan containing heavy metals with the following concentration value on analysis: Pb = 266028ppm, Fe=55871ppm, Sb = 7962 ppm, Cu = 500ppm, Mn=292ppm, and Zn=151ppm was recycled to produce glazed tiles. The slag was finely ground and mixed with clay in varying proportions; kaolin, feldspar, CaCO3, ZnO, Na2SiO4, CaSO4.2H2O, CaO, Chamotte and bentonite were also added in varying quantities before mixing. The mix was casted under pressure and dried. The brisque temperature was around 800oC for 8 hours. The produced tiles had a white to brown colour before firing and ash-green colour after glazing. The tiles showed high abrasion resistance, good compact strength and are of a quality comparable to encaustic tiles.

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For this study the sediment samples were collected from Tapti basin near Chopra district jargon, Maharashtra, India. The samples were sedimented and concentrated by centrifuge method for extraction of clay. X-ray Diffaction (XRD) and Scan Electron Microscopy (SEM) analysis have been carried out for the samples. The analysis indicate the clay samples contain Quartz (Silica) and Kaolinite minerals while smectite was found in traces. Beside the above analysis the same samples have also been analysed for physico-chemical and metallic status.

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Three dimensional unsteady state flow of an incompressible viscous fluid in the presence of transverse magnetic field through an oscillating porous plate in a rotating system, when the whole system being in the state of solid body rotation with constant angular velocity about the z-axis normal to the plate is discussed. The cases of uniform suction and injection (blowing) on the boundary has been considered. The effects of the magnetic parameter, porous medium, the suction and injection (blowing) on the velocity field, skin friction and temperature distribution has been shown graphically. It is found that the velocity field can be controlled by proper selection of porosity factor and or magnetic field parameter in both cases of suction/injection.

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Viscosity and density of three binary mixtures of methoxyethanol with heptane, benzene and 1,4-dioxane have been measured at 308 K. the experimental date of viscosity were compared with theoretical values calculated by using various empirical relations. Further, the excess molar volume VE, viscosity deviation Dh, excess viscosity D1nh and excess Gibbs energy of activation DG*E of viscous flow have been calculated. The results are interpreted in terms of interactions.

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A compound CuNiTiO4 is prepared by Solid diffusion method in the laboratory using standard chemical crystallographic of CuNiTiO4 is done using XRD. The Electrical properties are studied under which the variation of electrical conductivity with respect to temperature is obtained and type of charge carriers is determine electrical resistivity of the sample can be measured with dc or ac method. In the present work dc method is used, using LCR meter for the resistivity measurements.

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The Electronic absorption spectra of Co-phthalocyanine (CoPc) have been recorded with a view to study the solvent-solute interaction, H-bonding effect and its protonation in the solvents of different polarity especially in sulphuric acid of different strength. The study revealed that the CoPc acts as a weak monoacidic base in aqueous acidic solution. The hypsochromic shift of lmax was observed when concentration of sulphuric acid decreased from 36N to 6N suggesting the formation of H-bonding of H2S2O7 with atom N(2), N(3) and N(4) of CoPc and extra cyclic monoprotonation occurred irrespective to the concentration of H2SO4.

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The Objective of the study is to design oral controlled drug delivery systems for highly water-soluble drugs, using Hydroxypropyl methyl cellulose (HPMC)- a non-ionic hydrogel. Metoprolol tartarate was chosen as a model drug because of its high water solubility¹. Matrix tablets containing about 35% of HPMC were prepared by wet granulation technique. The matrix tablets were evaluated for hardness, thickness, uniformity and subjected to in vitro drug release studies. The drug release from the metoprolol tartarate matrix tablets was according to Higuchi?s laws showed a quicker release at the beginning and slower at the end which is a characteristic of an inert matrix with pores. The result indicated that HPMC is a potent carrier in the design of oral controlled drug delivery systems for highly water soluble drugs such as metoprolol tartarate.

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The vibrational (Infrared and Raman) spectra of 2-Chloro-6-fluoro benzaldehyde have been reported. The assignments of fundamentals are proposed and discussed by assuming the molecule under CS point group symmetry.

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The inhibition effect of imidazole on the corrosion of mild steel in acid medium has been studied by mass loss and polarization techniques between 303 K and 333K. The inhibtion efficiency increased with increase in concentration of inhibitor and temperature from 303 K to 318 K for both acids. But higher temperature at 333K the inhibition efficiency decreased. The corrosion rate increases with increase in temperature and decreases with increase in concentration of inhibitor compare to blank. The adsorption of this compound on the mild steel surface has been found to obey Temkin's adsorption isotherm. Potentiostatic polarization results reveal that imidazole is a mixed type inhibitor. The values of activation energy (Ea) and free energy of adsorption (DG ads) were also calculated.

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