VOLUME 25, NO1, MAR 2003

Assessment of Pollutants and its Impacts on the Drinking Water Quality of Malakand Division, Pakistan

The drinking water samples collected from different localities of Malak and division were chemically examined for pH, conductance, hardness, various anions such as cr·, 80.2, F 1, NO)'., cations like Na+, K+ and total iron. The values were compared with standards of various health agencies and all the parameters were found within the permissible limits. The toxic effect of these parameters has also been discussed.read more

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S ALAM ,F K BANGASH ,

A Simple and Low Cost Set -Up for Surface Tension Measurement of Highly Viscous Liquids

A simple and low-cost set up has been described for measurement of surface tension of highly viscous liquids by drop-weight method. The set up has been described in literature for normal liquids. Data in terms of VIK and corresponding factor F are given in literature for normal liquids. An equation has been developed between VlK versus a factor F by polynomial regression using EXCEL-2000 spreadsheet software in Window-98. Here V is volume of drop of liquid passing through a tube of radius R. The tube of3mm internal diameter has been used and this diameter has been measured by a vernier caliper. The setup has been applied to glycerol and the results are accurate within ± 2.5% of literature values obtained by this simple setup. Further this apparatus has been used in determination of viscosity of commercial highly viscous unknown liquids. The results are reproducible. This simple apparatus can be used in Physical Chemistry practicals, with the help of the cubic equation found from EXCEL-2000 software. read more

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A R SOLANGI ,A W K KHANZADA ,

Durability of Passivation in Zinc Electroplating

The durability of passivation in zinc electroplating has been studied using weak acid zinc bath free from cyanide and ammonia for zinc plating. and yellow and noncolored passivating solutions for passivation process. At the running voltage of 1.1 V, amperage ofl A. pH S-S.4, and at room temperature, best plating results were obtained from the zinc bath. The plated sample was washed in distilled water and then dipped in dilute HN03 for two seconds to make zinc plated surface active toward accepting fmal passivating film. The sample was then dipped in passivating solutions; cllromate film developed on the zinc surface, which protected it against corrosion as well as gave it an attractive appearance. It was found that yellow passivation at dipping time of one minute and at room temperature with the passivating solution composition of cr03 SO gIL, H2S04 1 mIlL, HN03 3 milL gives best corrosion resistance but weak abrasion resistance, while on the other hand colorless passivating solution comprising Cr03 2 g/L, KF 4 g/L and HN03 3 mIlL gives good abrasion resistance with weak corrosion resistance. read more

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I SADIQ ,I U HAQUE ,N AHMAD ,

Effect of Nature of Solvent on Viscosity of Poly-(methyl methacrylate) (PMMA)

Poly(methyl methacrylate) (PMMA) samples of molecullU" weight 6.49xl04 ­12.68xlO" were investigated for their intrinsic viscosity, unperturbed chain dimension and chain expansion parameters in acetone and acetonitrile in the temperature rangelO°. 4O"C. MlIIk-Houwink's constants 'K' and 'a' lU"e determined for the systems the data show that the 9 temperature for PMMA-Acetonitrile system is round about 35"C. Ke values have been predicted from various theoretical models and complU"ed with experimental values, on the basis of which Ahmad-Baloch (AB) model is regarded as best for the theta solvent and Stockmayer­Fixman (SF) model for the good solvent. Using purely viscosity data radius of gyration (Rc> and expansion factor 'a' have also been calculated for both the systems and has been discussed.read more

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A KHAN ,K MAHMOOD ,A SAEED ,

Solvent Dependent 14N Chemical Shifts in Oxine and 2-Methyloxine

Solvent effect on 14N NMR chemical shifts of oxine (8-hydroxyquinoline) and 2­methyloxine (8-hydroxyquina1dine) has been studied. The resuhs have been discussed in term of hydrogen-bonding and solvent polarity effects using DMSO-d,s as an internal locking agent and NH.NO] as an external standard. Concentrated solutions have been used to get better signal to noise ratio.1~ chemical shift ofoxine and 2-methyloxine in CCL. are very low i.e. -245.24 ± 14.09 ppm and -148.48 ± 31.18 ppm for oxine and 2-methyloxine respectively. Both compounds show very high shifts in chloroform i.e. -73.95 ± 3.24 ppm and -80.06 ± 14.50 ppm respectively. In acetone and DMSO both oxines, show similar behavior. Oxine shows extremely low 14N chemical shifts in Dioxane i.e. -288.85 ± 1.09 ppm.The present study on 14N chemical. shifts has been done at a frequency of 6.43 MHz using JEOL FX- 90Q IT NMR. A delay time of 400 I!s has been used to avoid the base line rolling due to low frequency and acoustic ringing. NH.NO] has been taken as an external standard and 14N chemical shifts have been measured with respect to NO]" ion of NH.NO].read more

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A W K KHANZADA ,S A PATHAN ,

Sorption of Phosphate on Cobalt Hydroxide

The sorption of phosphate on cobalt hydroxide is studied as a function of temperature (25 - 55 DC) and concentration (1.94 - 3.23 mmol/l). The mechanism of sorption is observed to be the replacement of OU· anions from the adsorbent surface by those of phosphate from the aqueous solution. A modified form ofthe Langmuir equation was used to explain the ion exchange sorption of phosphate on the Co(OUh. The IR studies of phosphate sorption are also made to determine the nature of phosphate ion bonding with the surface of the adsorbent. read more

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N REHANA ,A NAEEM ,M SAFDAR ,S MUSTAFA ,G NAWAB ,N REHANA ,A NAEEM ,G NAWAB ,M SAFDAR ,

Spectrophotometric Determination of Metal Complexes of 1-(2 Pyridylazo)-2-naphthol in Micellar Medium

Spectrophotometeric determination of cadmium(II), mercury(II) and manganese(ll) is carried out with 1-(2 pyridylazo)-2-naphthol as complexing reagent in aqueous phase using non-ionic surfactant Tween 80. The molar absorptivity, Sandell's sensitivity, critical micelle concentration, 1-(2 pyridylazo )-2-naphthol and metal ion concentration are studied. The method has been applied to the determination of these metal ions in municipal sewerage water and pharmaceutical samples.read more

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M I BHANGER ,G A SHAR ,

Synthesis and Characterisation of Cu(II) Com plexes with Schiff Base of Salicylidene-4- Tri-flouro-methyl Aniline and its Hydrogen Analogu

Schiff base of 4-triflouromethyl aniline and salicyaldehyde (,4 -CF3 SAL) and its Cu complex wu synthesized and characterized by using different spectroscopic techniques i.e NMR, UV, IR, and mass spectra. These were studied' in comparison with its hydrogen analogue (salicylidene 4-methyl aniline) and cOrTesponding Cu complex, with respect to its stability, peak. shift and functional group effect on vibrational spectra. and pharmaceutical samplesread more

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S R GILANI ,Z MAHMOOD ,

Profile of Metal Contents of Sewage Contaminated Canal Fishes

The metal contents of ten fish species collected from sewage contaminated Fuleli canal and fresh water (River Indus) were analysed by flame atomic absorption spectrometry after wet acid digestion. The metal contents varied differently in fish communities found in the area under investigation. Iron contents in all the fishes analysed was highest within the range S.33-40.2 uglg. The other metals analysed were within the limits manganese 0.11-8.11 uglg. zinc 2.1-16.2 uglg. copper 0.38-1.77 uglg. lead 0.38-2.3 uglg. nickel 0.2S-O.89 uglg, cobalt upto O.S uglg and cadmium was below the detection limits. Major metals sodium, potassium, calcium and magnesium contents in the fishes were also determined. The potasisum was in high cocnentration upto 4918 uglg.read more

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I A ANSARI ,S A KHAH ,V K DEWANI ,M Y KHUHAWAR ,

Syntheses and Structure Determination of Allyl Complexes of Molybdenum

The syntheses and characterization of molybdenum tetracarbonyl complexes of pyridyl amine Schiff's base ligands of type [Mo(CO).N"N») are described. These have been prepared by the reaction of cis-[M(CO).(Piphl with the Schiff' base ligands. The crystal slructures of the [Mo(CO).{N(Me)=C(Me)C,H.eN}] and [Mo(CO).{N(Me)-C(Ph)C,H.eN}] have also been determined.read more

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Z MAHMOOD ,S R GILANI ,