VOLUME 28, NO6, DEC 2006

An investigation into the Thermal Behavior of Tharparker Coal

Four coal samples from the Islam Kot, (Tharparkar) were characterized by Thermogravimetric (TG) analysis. Thermal decompositions were carried out in inert (pyrolysis) and air (combustion) atmosphere at temperature range 25’ 1000 C. Characteristic temperatures were determined from the burning profiles. Burning profile could provide a valuable rapid laboratory method of ranking coal in terms of burn out performances. Burning profile data were compared with volatile results. A comparison of the total H/C release from raw and dematerialized coal were made. The effect of sample amount, pyrolysis atmosphere, Nitrogen and Helium, particle size, heating rate and gas flow rate were studied. Peak temperature and bum out temperature were slightly decreased as the particle size decreased.read more

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A KARIM ,T AKHTAR ,F A KHAN ,M IQBAL ,

Relationship Between Compressive Strength and Applied Stress of a Diallyl Phthalate Coal Ash Blend

The compressive strength of a diallyl phthalate coal ash blend fabricated at pressures between 1000.4000 p.s.i, follows Michealais equation and shows a linear relationship between inverse of applied stress [I/V1 and inverse of composite compressive strength [I/S]read more

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S A H ZAIDI ,

Interaction of Acid Yellow 29 with Activated Carbon Prepared from Cellulosic Precursor: 1. Kinetics

Carbon prepared from the wood of Paulownia tomentosa (PT) was treated 1with mixture of acids (HCI and HNO3), KOH and n-hexane and activated at 400 and 800 oC. Activation removed the surface oxygen functional groups (carboxyl’s, lactones or phenols and ethers) and exposed the pores. Increase in the amount of carbon with respect to oxygen resulted which enhanced the dye adsorption. First order and Bangham kinetic equations were found to apply to the data, indicating the adsorption to be diffusion controlled. Rate constant increased with the increase in both the adscription temperature and the activation temperature of carbon. Thermodynamic parameters of adsorption (Ea, DH, DS and DG) were calculated. The endothermic nature adsorption was indicated by the positive values of 4H’. Negative values of DS found for adsorption, reflect decrease in the disorder of the system at the solid-solution interface during adsorption. Gibbs free energy (DG¹), that represent the driving force’ for the affinity of dye for the carbon, increased with the decrease in adsorption temperature but increased with activation temperature of the carbon.read more

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S ALAM ,F K BANGASH ,

Hydrometallurgical Studies for the Extraction and Recovery of Cobalt (II) with Tertiary Amies

The Investigations describe a comparative study with various high molecular weight tertiary Amines to develop a hydrometallurgical method for the extraction and recovery of Co (II) from aqueous acidic media. Limits such as, the effect of acid. extractant and stripping agents concentration, time of contact, and diverse ions were optimized. Maximum percentage extraction and recovery of Cobalt (II) ions were achieved with 5 % solution of trioctylamine in benzene.read more

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H KAMAL ,K KHAN ,K ALI ,

Impedance study of PVAc-Glycerin based Polymeric Gel at different Temperatures

Proton conducting polyelectrolyte gel was prepared by mixing different ratios of Poly vinyl acetate (PVAc) : Zirconyl Oxychioride Octahydrate (ZrOCI28H2O): Glycerin. The gel was yellowish in color, its conductivity was determined by standard AC impedance method at a temperature range of 20 °C to 80 °C. The conductivity showed increase with temperature and followed Arrhenius behavior. The polyelectrolyte was found to be showing no morphological transitions and stable thermally.read more

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M S KHAN ,S U KHAN ,

Electrochemical study of Hydrogen-Bonding in Anthraquinones

The electrochemistry of five anthraquinones is focused to interpret the intermolecular hydrogen bonding in the presence of four different a1cohoI, on the basis of their increasing acidity, as proton donors. The quinones were investigated systematically in dichiorornethane; acetonitrite and propylene carbonate while the half wave redox potentials were measured through cyclic voltammeter. The hydrogen bonding power was analysed from the positive shifts in both the redox waves showing proportional increase with. alcohol concentration. The quantitative data was obtained while calculating the thermodynamic association constants and number of alcohol molecules bonded to both anion and dianion of quinones. Both qualitative and quantitative data revealed the quinine-alcohol interaction as hydrogen bonding while strength of hydrogen bond is dependant upon the nature of species involved in this couple. It has been proposed that the basicity of quinone and acidity of the hydroxyl additive both favour the strength of hydrogen bonding.read more

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A Y KHAN ,R QURESHI ,S AHMED ,

Synthesis and Charcterization of Functionalized Polypropylene with Maleic Anhydride

Grafting of maleic anhydride onto polypropylene in xylene medium initiated by benzoyl peroxide under nitrogen atmosphere has been studied. The effects of reaction time. Reaction temperature, maleic anhydride concentration, benzoyl peroxide and material to monomer ratio have been studied in terms of 34 GE and % Add-on, The optimum conditions obtained for the grafting of maleic anhydride on 5.0 g of polypropylene were [BPO] 8.25 x 10 mol/L, (MAHI 2.04 x 10 mol/L. temperature 120 °C, time = 300 mm and polypropylene to solvent ratio 1:2 0. The graft copolymèr was characterized by FTIR spectrum.read more

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M AIJAZ ,A U SIDDIQUI ,Z H FAROOQUI ,KHALIL AHMED ,

Co-ordination of Trace Metal Ions with Glycine Amino Acid a Neuroreceptor in Biological System

Glycine is a simples non essential amino acid. It is present in high concentrators in central nervous system (CNS), involved in neural excitability Inhibitory neurotransrnissions in the mammalian CNS is mainly mediated by glycine. In the present investigation studied the cornplexing properties of glycine molecule with trace metal ions such as Fe+3, Al+3, Cr+3, Mg+2, Zn+2, Ca+2, Cu+2’, Ni+2 and Co+2. Potentiometrically and spectrophotornetrically the role ratio method were applied for the calculation of mole ratio between metal ions and ligand molecules.read more

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M NIAZ ,F S REHMANI ,

New Co(II), and Cu(II) and Ni(II) Complexes with 1,2-Bis(o-aminophenoxy)ethane

1, 2.Bis(o-aminophenoxy)ethane was prepared in a one stage process in this reaction, Pd/C was. used as catalyst.1, 2-Bis(o-aminophenoxy)ethane was synthesized from 1 ,2-bis(o-nitrophenoxylethane. Diamine complexes [CoLCI22H2O], [CuLCI2]0.5H2O.and [NIL2 (C2H5O)2] have been synthesized and characterized by elemental analyses, AM, IR UV-VIS. ‘H-NMR and magnetic measurements. read more

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H TEMEL ,M SEKERCI ,N TOKMAK ,

Flow Injection Analysis of Blood Urea in Combination with a Trinitrate Cellulose Based Mini Enzyme Reactor and a Modified Potentiometric Ammonium Ion Transducer

A flow injection analysis method for blood urea has been described in combination with a modified poly (vinyl chloride)-nonaction potentiometric ammonium ion transducer. The urease enzyme has been effectively immobilized on a 5 mm trinitrate cellulose membrane by covalent cross linking. Reusability, stability and durability regarding the activity of the immobilized enzyme has been successfully demonstrated. It has been proposed that such membrane filters can be an effective base material in comparison to a column type enzyme reactor for immobilization of enzyme due to their large available hollow space.read more

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S B BUTT ,