[en] Seventeen vegetables procured from local markets of Peshawar and its suburbs were analyzed using wet digestion atomic absorption method for Fe, Pb, As, Hg, Cd, Cr, and Ni. The families investigated were: Cucurbitaceae, Solanaceae, Cruciferae, Liliaceae, Araceae, Leguminosae, Malvaceae, Umbelliferae and Zingiberaceae. The heavy metal data are reported at 99%(- + 2S) confidence level for triplicate measurements on sub samples of a given sample with an overall reproducibility of 2% compared with standard material samples. Comparison of averages through t-test indicates that each vegetable group is distinctly different from the other in terms of metal content. Maximum iron was present in garlic, at 4.585 mu g/g, dry weight (edible part-stem) of the Liliacease family. Arsenic was found to be below detection limit in all the vegetable groups. Lead levels were quite low, maximum concentration (0.0200 mu g/g, dry weight) was found in karaila (edible part-fruit). Mercury levels were relatively higher, with maximum concentration (2.590 mu g/g, dry weight) in gem (edible part-stem). The levels of nickel were moderately higher, being maximum (2.375 mu g/g dry weight) in karaila. The overall content of trace metals appeared to be within laid down internationally for safe human consumption, with only a few exceptions. (author)

[en] Levels of eleven trace metals in edible muscle of seven commercial fish species harvested from the south west coast of the Arabian Sea, Pakistan are reported. The maximum concentration was found in case of Zn (3.412 mu g/g) and Fe(3.591 mu g/g). Maximum Ag (0.273 mu g/g) was found in Argyrops spinifer and As (0.041 mu g/g) in Choetodon jayakeri. The metal concentrations showed a high species-specificity. (author)

[en] Phosphate desorption from soil as a function of pH and temperature, using electrolyte and ion exchange resin methods, has been studied. The resin method is found to be the most suitable method for the extraction of phosphate from the soil. Low pH values and high temperature was observed to enhance the phosphate desorption which is due to an increase in the solubility of calcium phosphate. (author)

[en] This paper discusses the utilization of bagasse ash from the sugar mills of North West Frontier Province (NWFP), Pakistan in the raw mix designing for high strength Portland cement and its impact on clinker moduli and fuel consumption. The resulting clinker and cement was found with in the British and Pakistan standard specifications. 5% bagasse ash was found as the optimal limit to be blended and pulverized with other raw material prior to clinkerization which saved 6.46% energy. Among the moduli modulus of alumina (MA), modulus of silica (MS) and lime saturation factor (LSF) were studied. It was found that with 5% bagasse ash, all the moduli remained with in standards. (author)

[en] Three chiral bibenzimidazoles were synthesized by condensation of a-phenylenediamine with L-(+)-glutamic acid, L-(+)-aspartic acid and L-(+)-tariaric acid under microwave irradiation. promoted by polyphosphoric acid (PPA). Compared with the conventional heating methods, tile synthesis of bibenzimidazole compounds under microwave irradiation is rapid, economic and environmentally friendly method, with much higher yield. (author)

[en] A series of partially exchanged Cd/sup 2+/ A-zeolites (Cd/sub 0.86/ A, Cd/sub 1.7/ A Cd/sub 2.46/ A, Cd/sub 2.46/ A, Cd/sub 2.86/ A, Cd/sub 3.25 A/ were prepared by aqueous cation exchange technique from synthetic NaA-zeolite. The percentage of Cd/sup 2+/ ions exchanged increased with decreasing the concentration of Cd/sup 2+/ions and increasing temperature of the exchanging solution. This behaviour of Cd/sup 2+/ ion exchange with concentration is attributed due to volume effect, salt imbibent and electroselectivity effect. The uptake of Cd/sup 2+/ ions increased with rise in temperature indicated the process to be endothermic. lon- exchange isotherms plotted at different temperatures showed the type a isotherm i.e, the entering ion (Cd/sup 2+/) indicated selectivity to the outgoing ions (Na). The ion-exchange equilibrium data also followed the Freundlich and Langmuir adsorption isotherms. Themogravimetric analysis (TGA) showed that the zeolitic water depends on the number of Na/sup +/ and Cd/sup 2+/ ions per unit cell (p.u.c.). Thermal analysis curves showed that the minimum endothermic peak of dehydration slightly shifted towards higher temperature for CdA-zeolites indicated that water molecules are more strongly bonded to Cd/sup 2+/ than Na/sup +/. Three exotherms were clearly observed within the temperature range 780-1000 degree C, which are indicative of more than one reaction or crystallization of more phases. The differential thermal analysis (DT A) curves showed that dehydrated NaA zeolite retained its stability from 340 to 780 degree C and CdNaA-zeolites from 330-380 degree C to 800-820 degree C, NaA amorphisized at 920 degree C and CdNaA-zeolite, from 920 to above 1000 degree C. (author)

[en] A series of ten newly synthesized compounds are reported by adopting environment friendly microwave irradiation methodology, with an idea that these compounds will be tested for in vitro antibacterial and antifungal activity In combination to microwave radiation and tributylammonium bromide (TBAB), triethylbenzylammonium chloride (TEBAC) and polyethylene glycol (PEG) were used as phase transfer catalysts in non toxic solvent for reaction activation and TBAB showed better yields. Chromatographic techniques such as Thin Layer Chromatography, Flash Chromatography, Column Chromatography were used for purification and the average yield of all compounds was found to be 76.96 %. Structural elucidation was carried out using FTIR, /sub -1/ H- NMR, elemental analyzer and MS. The synthesized compounds were checked for their antibacterial activity (in-vivo) and it was found that compounds exhibited different antibacterial activities depending on tile nature and position of the substituents on the thiazolidinone ring. The most active compound 1/sub d/ and showed broad spectrum antibacterial activities. (author)

[en] The current quality status of ground water from the Hazara strip, NWFP, was investigated in 63 samples using standard analytical procedures and the AAS method. The parameters included in the study were pH, temperature, TDS, conductance, hardness, chloride, sulfate and bicarbonate. The metal included in the study were Na, K, Ca, Mg, Fe, Cu, Zn, Pb, Cd, Ni, Cr and As. The water samples for analysis were drawn from wells ranging in depth from 4 to 63 m. The waters ranged in pH from 6.23-7.75 and in conductance from 153 to 1688 mu S/cm. Almost all the waters were the found to be genuinely hard (64 mg/L to 600 mg/L hardness, CaCO/sub 3/) and have fairly high chloride concentration. The bicarbonate alkalinity ranged from 130 mg/L to 972 mg/L. The essential metal concentration followed the order Zn>Fe>Cu, with corresponding ranges of 0.001-0.043 mg/L, 0.004-0.062 mg/L and 0.006-11.65 mg/L for Cu, Fe and Zn, respectively. For As, the concentration ranged from 0.061 mg/L to 2.131 mg/L thus exceeding the upper permissible safe limit of 0.05 mg/L laid down by WHO. The statistical correlation study showed strong positive correlations between Na-Ca and Mg. Correlation study in relation to water evidenced a positive correlation for macro nutrients and essential metals in general, while a negative interdependence was observed for non essential metals. (author)

[en] Physical and mechanical properties of zirconium metal and its alloys such as resistance to corrosion in hot water, transparency to thermal neutron show its suitability as construction material in nuclear reactors as fuel cladding and pressure tube material in water cooled nuclear reactors. Presence of gaseous impurities like hydrogen, nitrogen and oxygen affect mechanical and corrosion resistance properties of zirconium metal and its alloys. For the production control and metallurgical evaluation of such effects, accurate and precise determination of these impurities is essential. Some selected samples of zirconium metal, its alloys, sponge zirconium, and ingot have been analyzed for the estimation of hydrogen, oxygen and nitrogen impurities in micro amount by melt extraction technique under argon and helium carrier gas stream for hydrogen, oxygen and nitrogen respectively. All the systems were completely optimized in different weight and temperature conditions and the accuracy of the results obtained was statistically evaluated at 5% confidence level. Non-metallic impurities in zirconium metal and alloy samples were found to be in the range of 16-56, 45- 118 and 1008-1826 ppm for hydrogen, nitrogen and oxygen respectively. (author)

[en] Different sample treatment procedure such as dry ashing and wet digestion are commonly used to decompose biological materials and to bring the elements of interest into the measurable form. A number of reagents such as aqua, HNO/sub 3//H/sub 2/O/sub 2/,HNO/sub 3//HCIO/sub 4/ etc. are used to solubilize metals form biological matrix. In this study, performance of dry ashing and wet digestion method has been compared for the estimation of zinc and calcium levels in the whole body freshwater fish samples. Flame atomic absorption spectrometry has been used as an analytical tool to quantify the metals. Results based on dry ashing and wet digestion methods for zinc differ significantly. Wet digestion method gives mostly higher zinc values compared to dry ashing method which indicates the possible losses of zinc during the ashing of fish samples at elevated temperature, i.e. 500 deg. C. Higher recoveries of calcium in the whole body freshwater fish samples have been obtained following wet digestion procedure using strontium as releasing agent compared to calcium determination following dry ashing method (with and without strontium) and wet digestion method without strontium which suggests the use of a releasing agent (strontium) minimizes the chemical interference of phosphate while determining calcium by flame atomic absorption spectrometry. (author)