VOLUME 25, NO2, JUN 2003

X-ray Diffraction and Mercury Porosimeter Examination of Metal Impregnated y-Alumina Samples

A series of metal impregnated alumina has been prepared by simple impregnation method of the host oxide (y-alumina). In the present paper, two techniques, X-Ray Diffraction and Mercury Porosimeter have been applied for examining the effect of different concentrations of transition metals (Cr, Mn, Fe and Co) loaded on y-alumina. read more

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A K KHATTAK ,R QADEER ,M SALEEM ,M AFZAL ,K MAHMOOD ,

Determination of Vinyl Acetate (VA) Content of Ethylene-vinyl Acetate (EVA) Copolymers in Thick Films by Infrared Spectroscopy

The infrared spectroscopic method was applied for the determination of vinyl acetate '(VA) content in thick films of ethylene-vinyl acetate (EVA) copolymers. From spectral analysis, the A34<IO!'A3610 ratio was used for quantitative determination. This technical measurement is simple, quick, does not require a complicated sample preparation method and also does not need a tedious calculation procedure for the exact determination of vinyl acetate (V A) content. The overall procedure, thus adopted, presents an excellent resemblance with different practically applied methods.read more

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N U JAMROZ ,

Prolysis of Metals Ions Exchanged Coal

The influence of cations (Na" K" ea2+, M~, Fe2" Fe3" A13+, eu2+ and Ba~ on the pyrolysis behavior of high volatile bituminous coal from middle seam Kost-Sharigh-Hamai coalfield Baluchistan under flash heating conditions was investigated using open tubular type pyrolyzer. Initial pyrolysis experiments were performed with de-mineralized and ion exchanged coal samples at 650 ·C. The production of methane, ethane, ethylene, propylene + propane, I-butene, n-butane. I-pentene, n-pentane and benzene was monitored gas chromatog,:aphically. The addition of metal ions showed variable effect on the yield of pyrolysis products. The yield of benzene increased 5-6 fold for ea and Mg exchanged coal compared to de-mineralized coal. Effect oftemperature on the yield of benzene was explored over the temperature range 500-800 ·C for the pyrolysis of ea and Mg exchanged coal. The yield of benzene was higher than the de-mineralized coal at all temperatures and showed a decrease with increase in temperature.read more

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T MAHMOOD ,I A AWAN ,J NISAR ,A YAMIN ,

Optimization of Process Parameters for the Production of Battery Grade Acetic Silver Powder

Various process parameters involved in the production ofbanery grade acetic silver powder having specified characteristics have been optimized and the acetic silver powder produced at optimized process parameters was characterized. Results reveal that the activity of synthesized acetic silver powder matcbed fairly well with the activity of imported material and is also economical cost wise. It has purity ~ 99% and contains Fe and Cu as traces having concentration of20 ± 6 ppm and 30 ± 5 ppm respectively. XRD studies show that acetic silver powder has a cubic structure.read more

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R QADEER ,A MUNIR ,S IKRAM ,M S ANJUM ,

Effect of Precipitation on the Sorption of Metals Cations by AlPO4

The precipitation of divalent metal cations Cu2+, Zn2+. Ni2+ and Mg2+ with and without A1PO. is measured potentiometrically as a function of temperature and concentration of the divalent metal cations. The shift of the titration curves at a given temperature in the presence of exchanger is related to the metal ions adsorption at the pH valuea below the plateau formation in the titration curves. The order of precipitation of the divalent metal cations is observed to be Cu2+ > Zn2+ > Ni2+ > Mg2+ which is parallel to the values of their solubility products. Law of mass action is applied to distinguish between the ion exchange sorption and precipitation of the metal cations. It is found that the process of the uptake of metal cations changes from adsorption to precipitation with the increase in concentration, pH and temperature of the system.read more

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S MURTAZA ,A NAEEM ,N REHANA ,S MUSTAFA ,B DILHARA ,

Measurement of Traditional Air Pollutants in Industrial Areas of Karachi, Pakistan

Continuous measurement of traditional air pollutants alongwith meteorological p'arameters was carried out by air pollution Mobile Monitoring Laboratory at industrial areas of Karachi. Average concentration ofS02 at Sindh Industrial Trading Estate was found to be 24.9 fL8Im3 and PMIO (Particulate matter) was 176.5 fL8Im3• whereas the average concentration of S02 at Korangi Industrial Area was 7.4 fL8Im3 and PMIO was 147.2 fL8Im3 respectively. These data were compared with the uptown area of Karachi. The result suggested that S~ and PMI0 found in these areas shows similar variation, which indicates that, these pollutants originate from the same source. Effect on human health is also discussed. read more

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M I QAIM KHANI ,D R HASHMI ,

Evaluation of Drinking Water from Different Sources in Skardu- Northern area with Special Reference to Heavy Metals

In Skardu and other northern area, demand for drinking water is met through both surface and subsurface water. No survey regarding the potability of water has been conducted in the past. Considering the importance of this survey, ten samples of drinking water from different sources were collected and analyzed for various parameters like pH, dissolved oxygen, electrical conductivity, suspended solids, alkalinity, hardness, nitrites, sulphates. chlorides, sodium, and potassium. They are also analyzed for heavy metals like iron, chromium, zinc, manganese. copper, nickel, cobalt and lead using atomic absorption spectrophotometer. The magnitude of different trace metals followed the order Zn > Fe> Ni > Pb> Co > Cu > Cr. Analysis indicate that there was no collinearity among the metals.read more

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U KALSOOM ,Z H LODHI ,M AKIF ,

Stability of Reactive Dyes in sunlight Changes in their Colour Coordinates

Fading on exposure in light is undoubtedly the '~ost complex of the reactions which dyes undergo on a fibre. Energy in the form of light is absorbed by the dye and causes some of its molecules to become unstable and under these conditions, the dye may react with surrounding materials. The decomposition of the dye subsequent to its photochemical activation occurs usually by reduction and in azo dyes the azo likage seems to be attacked. Dyes containing strongly electron donating substituents tend to fade oxidatively, whereas those with strongly electron withdrawing groups prefer a reductive degradation pathways. In dry state a reductive fading mechanism becomes oxidative. Fastness to washing, wet rubbing and perspiration also showed changes in colour coordinates of the dyes studied.read more

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C M ASHRAF ,S WAHEED ,

Vibrational Spectral Studies of the Complexes of Diacetamide with Metal (II) Halides

The FfIR Spectra between 4000-400 em·· and the Raman Spectra between 1800­1200 em·I, of the Complexes of diacetamide with metal (II) halides have been measured to distinguish the mode of coordination of ligand in these complexes. The diacetamide molecules in most of these complexes are acting as bidentate Iigands, Coordinating through both of their carbonyl oxygen atoms and are in cis - form. In Co [(DA). (H20hl Br2, although the diacetamide molecules are in cis - form but they are either acting as monodentate ligands or possibly two of them are uncoordinated as in the corresponding perchlorate complexes.read more

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D M L GOODGAME ,I HUSSAIN ,M GOODGAME ,

Quality Parameters and Its Impact on the Drinking Water of Peshawar Division, Pakistan

Drinking Water samples collected from different localities of Peshawar division were examined for different physico-chemical parameters such as pH, conductance, anions like crt, SO.-2, F1, N~·', cations such as Na+' K+, eu+2 lUId the total Iron. The values were compared with the standards of W.H.O lUId encyclopedia of environmental sciences and were found to he within the permissible limit except nitrite. The toxic effects of these parameters have also been discussed.read more

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F K BANGASH ,S ALAM ,