Table of Contents - Volume 12 Number 2

Lead Nitrate composite solid electrolyte system in different compositions was synthesized by dispersing nano particles of CeO₂ in the host Pb(NO₃)₂. These systems were characterized by XRD, DSC and FTIR. X-ray diffraction patterns have shown peaks corresponding to pure lead nitrate and cerium oxide in all the compositions with varying intensities and no additional or shifting of peaks were observed. DSC studies indicate uniform melting point in host and dispersed composites. FTIR  studies ruled out the chemical reaction between host and dispersoid.  Dc ionic conductivity studies were carried out in the temperature range 100^oC to 400^oC. Ionic conductivity was found to increase with mole percentage of the dispersoid with increase in temperature. Maximum enhancement was observed for 8mole% dispersed system as against the pure Pb(NO₃)₂ in the extrinsic region of conductivity. Enhanced conductivity in dispersed systems was thought to be due to the presence of Space Charge Layer between the host and dispersoid.

Hide Abstract

A new azo dye Schiff base ligand, namely 1, 1′-bis(5-(4-nitrophenyl)diazenyl)-2-hydroxybenzylideneamino)ethylenediimine (NDHBDED) has been synthesized and it was impregnated with alumina for extractive determination of metal ions. In this report the sorbent matrix was used for extractive determination of Mn (II) and Cu (II) ions by solid phase spectrophotometric (SPS) method. Both the metal ions were extracted at pH 6.5 and 5.5 respectively. The complexes show maximum absorbance at λ _max 590 nm and 570 nm respectively for Mn (II) and Cu (II) ions.  The Beer's law range was 10-100 µg/ ml for both the metal ions. Job’s method and mole-ratio method showed that metal-ligand ratio in the complexes to be 1:1.  The Molar absorptivity for Mn (II) and Cu (II) were 2.351x10^-4   L mol^-1 cm^-1 and 2.225x10^-4   L mol^-1 cm^-1 respectively. The Sandell’s sensitivity was 0.004 µg/ cm² and 0.008 µg/ cm² for Mn (II) and Cu (II) ions respectively. The proposed method was successfully applied to the determination of each metal ion in real samples and tap water.

Hide Abstract

In today’s highly competitive world where most businesses focus on cost and quality, organizations with efficient and effective machining are able to stand out with inherent competitive advantages.The attainment of high quality, in terms of dimensional accuracy, surface finish, high production rate and cost saving, with a reduced environmental effect is mostly concentrated by modern machining industries. Such goals are strongly affected by numerous fundamentals among unique of them is the cooling lubricants. The machinability with coolant in turning operation with flood coolant, MQL and cryogenic cooling and it is perceived that surface finish, cutting forces, chip formation and tool wear are all affected with the type of coolant, cutting speed, depth of cut and feed rate have examined by plenty of authors. The steam as a coolant has been selected to discover the machinability of titanium alloy with the introduction of environmental friendly coolant because very little analysis in steam as coolant is present in the literature.

Hide Abstract

The polyaniline can be synthesized by oxidative polymerization of aniline. The PANI-based nano-composites can be synthesized by the method of polymerization. The oxides of copper are intrinsic p-type semiconductors with relatively small band gaps and show many attractive properties that can be utilized in a diversity of applications This paper includes synthesis of CuO nano-particles, and the polyaniline-CuO nano-composites with five different percentages of CuO nano particles. These samples were characterized by XRD and SEM.

Hide Abstract

Aluminium matrix composites reinforced with ceramic particulates, have significant applications in the field of aerospace, marine, automobiles, sports and recreation. In the present investigation, the corrosion behaviour of Al 6061-TiO₂ particulate composites prepared by liquid metallurgy, has been studied in chloride, nitrate and sulphate media using electroanalytical techniques such as Tafel, Cyclic polarization and Impedance (EIS) measurements. Surface morphology of the sample electrodes was examined using Scanning electron micrography (SEM) and Energy dispersive x-ray (EDX) analysis methods. To confirm the inclusion of TiO₂ particulates in the matrix alloy and identify the alloying elements and intermetallic compounds in the Al 6061 composites, XRD technique was used. The polarization studies indicate an increase in the corrosion resistance in composites compared to the matrix alloy. The results from all the media studied indicates that the relative degree of corrosion follows the order Cl¯ > NO₃^¯̶ > SO₄²¯. The EIS study reveal that the polarisation resistance (R_p) increase with increase in TiO₂ content in composites confirming improved corrosion resistance in composites. The observed increase in corrosion resistance of TiO₂ particulate reinforced composites is believed to be due to the action of TiO₂ as physical barrier to the initiation and development of pitting corrosion, modifying the microstructure of matrix. The intermetallic phases AlFeSi rich and Mg₂Si formed, being conductive act as anodic to Al matrix and become the preferable sites for initial localised attack thus causing pits.

Hide Abstract