Table of Contents - Volume 10 Number 1

Circular section rods of Zn-22Al-2Cu (weight %) alloy were prepared by rapid solidification (103 K/s); a semi-continuous vertical cast device with mould cooled with water was used. Rods microstructure consisted of two-phase dendritic cells surrounded by lamellar eutectic and, it is found that cell size depends on the growth rate. Starting from an overheated melt at 540°C and a rod growth rate of 0.23 cm sec^-1 a fine microstructure is obtained. From  X-Ray Diffraction and Energy Dispersive Spectroscopy studies, alternating lamellas of α'_s and η'_s phases are conforming the cells and inter dendritic zone. Rod samples were prepared and tested in tension, offset yield strength of 395 MPa, modulus of elasticity of E = 197.5 GPa, tensile strength of 497 MPa and a percentage elongation of 20 to 28 % were measured. These values are higher than those obtained from pieces prepared by permanent mould casting using the same alloy.

Hide Abstract

Polystyrene, polypropylene and polyethylene terephthalate mixture into fuel recover experiment was performing into laboratory scale. Batch process experiment was setup under labconco fume hood without vacuum system. Experimental purpose total waste plastics was use 100 gm and sample ration was PP 40g, PS 40 g and PETE 20 g by weight. Product fuel density is 0.79 g/ml and fuel color is light yellow. PP, PS and PETE mixture to fuel conversion rate was 78%. Product fuel was analysis by GC/MS and compounds range obtain C₃ to C₂₄ including aromatic, aliphatic, oxygen content, halogen content, alcoholic and nitrogen content. Product fuel can use as a heating fuel and its can run combustion engines or feed for refinery process.

Hide Abstract

Heating a slab induced by laser irradiance is studied. The heat diffusion equation is solved using the Laplace integral transform method. The critical time tm required to initiate melting is obtained for the elements: Aluminum (Al), Gold (Au), Germanium (Ge) and Silicon (Si). Good cooling conditions at the rear surface of the slab are assumed. The obtained results show that for the considered elements and for such sources of high power density, cooling conditions at the rear surface are not of pronouncing effect. The effect of laser power density on the critical time required to initiate melting is predominant.

Hide Abstract

A polyamine (PA) was prepared by condensation of 1,4-bischloromethyl benzene and 1,4-benzenediamine. The PA was then treated with cyanuric chloride at 0_C followed by reaction with 4-amino naphthalene sulphonic acid in THF in concentration. NaOH (PH 9-10) at room temperature for 8 h. The resultant polymer, designated as polyamine-s-triazine-naphthalenesulphonic acid (PATS), was characterized by elemental analysis, IR spectral studies, and thermogravimetry. The PATS sample was monitored for its ion-exchanging properties by batch equilibrium method.

Hide Abstract

One of the most common therapeutic surface reactive bioresorbable implant material used nowadays is bioactive glass 45S5. However, being amorphous in nature, its usage in load bearing applications is ineffective due to its poor mechanical properties. A novel idea of toughening bioactive glass 45S5 would be to produce it as a glass ceramic with an optimum dispersion of a crystalline phase in the amorphous matrix so that crack deflection at and around crystals occur which would toughen bioactive glass ceramic by increasing the crack length. Partially crystallized bioactive glass therefore is a prime contender in the fabrication of a glass ceramic with improved fracture resistance. However, during crystallization it was observed that flowery patterns were produced inside the samples which upon analysis revealed to be inter-linked voids formed at the grain boundaries. These voids were formed as a result of shrinkage upon crystallization and may play influential part in the crack propagation behaviour in crystallized bioactive glass.

Hide Abstract

Salicylanilides possess a wide range of biological activities and they act as inhibitors of the two component regulatory system in bacteria. A natural bond orbital analysis has been performed in order to study intra-molecular bonding, interactions among bonds and delocalization of unpaired electrons for certain salicylanilide derivatives. Stability of the molecules arising from hyper conjugative interactions, charge delocalization has been analyzed. The electron density (ED) is transferred from the n(O), n(Cl) n(N) to the anti-bonding p*, s* orbital of the C-C ,C-O,C-N bonds. The results show that electron density in the anti-bonding orbitals and second order delocalization energies confirm the occurrence of intra-molecular charge transfer within the molecules.

Hide Abstract

A polyamine (PA) was prepared by condensation of 1,4-bischloromethyl benzene and 4,4'-diaminobiphenyl-3,3'-disulfonic acid. The PA was then treated with cyanuric chloride at 0_C followed by reaction with sulfanilic acid in THF in concentration. NaOH (PH 9-10) at room temperature for 8 h. The resultant polymer, designated as polyamine-s-triazine-sulfanilic acid (PATS), was characterized by elemental analysis, IR spectral studies, and thermogravimetry. The PATS sample was monitored for its ion-exchanging properties by batch equilibrium method.

Hide Abstract

A highly efficient device concept for solid-state hybrid dye-sensitized solar cells has been recently realized. It has been attracted extensive attention as a promising approach to achieve cost effective solar energy. The key property which makes solid-state hybrid dye-sensitized photovoltaic systems so attractive is the potential of simple fabrication and assembling technology. In this article, firstly, we review the recent developments including device operational mechanism of solid-state hybrid dye-sensitized solar cells incorporating inorganic nanoparticles as electron transporting material, an organic hole transport materials with photoexcited dye molecules as electron injector into the n-type material and the hole-accepting and transporting properties of polymer. In addition, the enhancement of photoresponse through interaction of near-IR dyes and the polymer hole-transport material have also discussed.

Hide Abstract

The aim is to provide a global approach on alternate fuels such as ethanol, biodiesel, vegetable oils, bio-oils, and other bio renewable liquid fuels for the future of energy of transportation. It is possible that sugarcane, corn, wood, straw and even household wastes may be economically converted to bio-fuels like ethanol and biodiesel.

Hide Abstract

This work is focused on the synthesis, characterization and computational studies of multiwall carbon nanotubes. Growth of pure carbon nanotubes have been carried out by vapor phase growth and thermal CVD methods. After optimizing the growth parameters for both methods, the multi-walled carbon nanotubes (MWCNTs) have been obtained. Best optimized temperatures are 900oC and 825oC for vapor phase growth and thermal CVD methods respectively, showing highest yield of CNTs. Average length of CNTs is around 72ìm for acetylene method, and 60ìm for xylene method for diameters range of 30-50nm. In the second stage, by using the geometrical parameters of the experimental observations, computational studies of CNTs are carried out to know the elastic bending and buckling behaviors of carbon nanotubes. A Finite Element (FE) approach has been made to analyze and study the bending deformations and buckling behavior of MWCNTs. The results calculated in this work, agree with the results of other similar numerical simulation studies available in the literature and then establishing the validity of the present FE approach. The results could be an instrument for studying the mechanical behaviors of MWCNTs and their usefulness in nanocomposite materials field. It can be used as a substitute competent method to study bending and buckling of the CNTs accurately.

Hide Abstract

Silica nanoparticles are of promising applications in many current and emerging areas of technology because of their nature advantages. This review is devoted to the progress made in the last decade in synthesis and green chemistry application of silica nanoparticles. We present a comprehensive overview of synthetic strategies for silica nanoparticles. The ability to control the particle size and distribution was found highly dependent on mixing modes of the reactants and drying techniques. Silica nanoparticles with good dispersion, different morphology and tuning pore sizes are successfully synthesized by means of the sol-gel method. Green chemistry application of synthesis of silica nanoparticle has drawn much attention, due to the increased demand for new materials with improved thermal, mechanical, physical, optical and chemical properties. And this application of silica nanoparticles in materials chemistry procedures to synthesize highly efficient silica nanoparticles and films that can be used for the treatment and disinfection of water and wastewater, and highly sensitive devices for the development of new type of sensors are mostly described. This paper is written by emphasizing on the synthesis of silica nanoparticle, characterization on size-dependent properties for the preparation of homogeneous nanocomposites, generally by sol-gel technique, and show great promise for use in variety of green chemistry applications where special structure and properties are required.

Hide Abstract

Metal complexes of Glipizide drug were prepared and characterized based on elemental analysis, FT-IR, Molar conductance and thermal analysis (TGA technique). From elemental analysis data, the complexes were proposed to have general formulae (C₂₁H₂₅N₅O₄S)2M. The molar conductance data reveals that both the complexes are non-electrolyte, IR spectra shows that the drug is coordinated to the metal ions in a neutral bidentate manner with OO donor sites of the amide O and sulphone O, from the ESR spectra, it is found that that the geometrical structures of these complexes are tetrahedral. The thermal behaviour of these complexes were studied using thermo gravimetric analysis technique. The result obtained shows that the hydrated complexes lose water molecules of hydration followed immediately by decomposition of the anions and the ligand molecules in the successive stages. Thermogravimetric analysis was carried out to study the decomposition and various kinetic parameters. Freeman Carroll and Sharp Wentworth method have been applied for calculation of kinetic parameters, while the data from Freeman Carroll method have been used to determine various thermodynamic parameters such as order of reaction, entropy change, free energy change and apparent entropy change.

Hide Abstract

The native oxide layers formed on amorphous alloy Fe₇₈B₁₃Si₉ before and after high energy heavy ion (Ni¹¹⁺ 150 MeV) irradiation, were characterized by X-ray photoelectron spectroscopy (XPS). The unirradiated specimen of the alloy consists of Fe³⁺ and Fe⁰ whereas the irradiated specimen contains only Fe³⁺ species. The B 1s and Si 2p spectra shows the presence of B³⁺ and Si⁴⁺ species most likely in the form of B₂O₃ and SiO₂ on the surfaces of both unirradiated and irradiated specimens of the alloy Fe₇₈B₁₃Si₉. The native oxide layer on the irradiated specimen contained higher amounts of oxides of B in comparison to unirradiated specimen.

Hide Abstract