[en] Physicochemical, microbiological and sensory parameters of concentrated pineapple juice stored in cans and glass bottles were studied over a period of ten weeks. There was slight increase in pH from 4.2 to 4.7 and to 4.8 and decrease in titratable acidity from 8.1 to 5.1 and to 4.6 mg/100 mL, whereas total solids (%) decreased from 76.23 to 65.47% and to 60.38% in canned and bottled pineapple concentrates, respectively. Over 90% loss of Vitamin C was observed, with the bottled samples retaining more Vitamin C than the canned samples. The microbial counts ranged from 2.0 X 103 to 2.4 X 104 cfu/mL whereas fungi and mesophilic bacteria, were not detected to 6 X 103 cfu/mL. Freshly prepared single strength juices of pineapple were better in terms of taste and colour, while the bottled reconstituted juice concentrate competed favourably with the fresh one in colour. The canned samples lost their colours within 10 weeks of storage. The glass bottled samples had a characteristic desirable aroma. Thus concentrated juice in glass bottles stored at room temperature enhanced the keeping quality of the juice and compared more favourably with the fresh juice than the canned concentrated juice. (author)

[en] Specimens of nineteen different global varieties of cotton were studied to determine their contribution to water hardness through calcium and magnesium impurities, resulting in various problems during textile pretreatment, colouration and finishing. Pakistani cotton was found to be the second most contaminated cotton in terms of calcium and magnesium impurities, whereas Elisa variety from Uzbekistan was the cleanest. (author)

[en] Measurement of carbon monoxide in the ambient air at 36 locations on the busy roads of Karachi showed peak values of CO at 18 sites to be within the permissible limit of 10 ppm whereas up to 70 ppm at the other 18 sites. The evaluated carboxy haemoglobin (COHb) level was in the range of 1.1 to 15.8 %. (author)

[en] The contents of lead as a pollutant in road side dust and vegetable samples of urban and rural areas of Lahore city, Pakistan, were monitored with the help of atomic absorption spectrophotometer. Average concentration of lead in dust samples collected from residential areas was 25 to 165 mgiL, from rural areas 9.5 to 13.0 mg/kg, from commercial areas 201 to 1685 mg/kg, and from canal side 105 to 220 mg/kg. In most oft he vegetable samples lead level was in the permissible range, whereas in some Samples the average lead concentration range form 0.13 to 5.0 mg/L. (author)

[en] In this study, adsorption of copper(lI) ions from aqueous solutions on sawdust, zeolite and activated carbon was studied using batch experiment techniques. The effect of different parameters such as pH of solution, adsorption time and amount of adsorbents were evaluated. Favourable pH for maximum copper adsorption was 6, 6 and 4 for sawdust, zeolite and activated carbon, respectively. The equilibrium of copper adsorption has been described by the Langmuir, Freundlich and Temkin isotherms and their fitness for adsorption was compared. The Temkin model had a better fitness than the other models. Maximum adsorption capacity of sawdust, zeolite and activated carbon were 96.11%, 96.2% and 97.02% (mg/g), respectively. The study of applicability of kinetic models of Lagergren (1898) and Ho et al. (1996) showed the latter model to be better fit than the former. The rates of adsorption obey the rules of A-order model with good correlation. In this study, adsorption of copper(lI) ions from aqueous solutions on sawdust, zeolite and activated carbon was studied using batch experiment techniques. The effect of different parameters such as pH of solution, adsorption time and amount of adsorbents were evaluated. Favourable pH for maximum copper adsorption was 6, 6 and 4 for sawdust, zeolite and activated carbon, respectively. The equilibrium of copper adsorption has been described by the Langmuir, Freundlich and Temkin isotherms and their fitness for adsorption was compared. The Temkin model had a better fitness than the other models. Maximum adsorption capacity of sawdust, zeolite and activated carbon were 96.11%, 96.2% and 97.02% (mg/g), respectively. The study of applicability of kinetic models of Lagergren (1898) and Ho et al. (1996) showed the latter model to be better fit than the former. The rates of adsorption obey the rules of A-order model with good correlation. (author)

[en] In soils of different areas of Quetta city, irrigated by sewage water, the highest concentration of heavy metals was found to be as follows: lead (1.38 ppm), copper (0.86 ppm), chromium (0.036 ppm), cadmium (0.29 ppm), iron (10.50 ppm), nickel (0.74 ppm), zinc (19.45 ppm) and arsenic (0.001 ppm) on average basis. The sewage water contained lead (53.26 ppb), copper (22.5 ppb), chromium (1.33 ppb), cadmium (0.53 ppb), iron (127.7 ppb), nickel (51.14 ppb), manganese (17.08 ppb), zinc (31.38 ppb) and arsenic (0.011 ppb). At each site the concentration of heavy metals and sewage water showed positive relationship. (author)

[en] Study of micro nutrients in the soil of Hazro area of District Attock (Potohar), Pakistan, revealed micronutrient deficiency in the order of Fe> Mn> Zn> Cu. All the soils were low to medium in Fe and Mn followed by Zn content, whereas only 8% samples had low Cu content. 92% and 18% soils in Hazro area had satisfactory to adequate Cu and Zinc contents, respectively, Thus soils were deficient in Fe, Mn and Zn, whereas Cu was in medium to adequate range. (author)

[en] Performance of injection moulded short wollastonite fibre and chopped glass fibre reinforced hybrid epoxy composites was studied. The results showed that hybridisation of glass fibre and wollastonite was in congruence to epoxy glass fibre composite system. Effect of fibre length, fibre orientation in matrix and analysis and fracture surface was undertaken. The mechanical properties of injection moulded, chopped glass fibre/wollastonite/epoxy hybrid composites were investigated by considering the effect of hybridization by these two fillers. It was observed that the tensile, flexural, and impact properties of the filled epoxy were higher than those of unfilled epoxy. The effect of filler on epoxy matrix subjected to the tensile strength and modulus was studied and compared with the rule of mixture. The actual results are marginally low as compared with the values obtained by the rule of hybrid mixtures (RoHM). (author)

[en] The wide use of petroleum products causes contamination of air, water, soil and plants. The present study was conducted to monitor the trace metal deposition in road side soil around the petrol filling stations along the busy roads of Karachi, Pakistan. Total 21 road side soil samples were collected from selected locations of busy roads. The soil samples were digested using acid digestion method and atomic absorption spectrophotometer (AAS) was used for the elemental analysis. Results of the study showed that concentration of lead was highest in the soil samples ranging from 41.3 to 361 mg/kg, then copper from 23.0 to 101 mg/kg, manganese from 36.2 to 125.0 mg/kg and zinc from 27.5 to 213.0 mg/kg, respectively. The correlation-coefficient (r) was also calculated between the metals in soil samples. The correlation matrix showed that all the pollution is coming from the same source. The gravitational sedimentation and impact on vegetation of coarse fraction is responsible for the high lead contamination of vegetation and soils. Collected data showed that, almost all the pollution being generated by automobile exhaust in urban areas of Karachi. The soil acts as an important sink for pollutants released through different activities. (author)

[en] The wastewater of a slaughterhouse was characterized for parameters like pH, COD, BOD, TDS and TSS. All parameters were above tile permissible limits of National Environmental Quality Standards of Pakistan. The slaughterhouse wastewater is rich in organic matter with BOD and COD being 5820 mgiL and 6970 mg/L, respectively. In this study, wastewater was treated by coagulation process using lime and alum (both individually and in combination) as coagulants. COD removal increased with increase in alum dose to a maximum of 92%. The high sludge volume made the process infeasible. Increase in lime dose increased the COD reduction to a maximum of 74%. The sludge settling speed was very high and sludge volume was low as compared with alum. The combined doses of lime and alum gave removal of COD to a maximum of 85% with sludge volume comparable to lime. The optimum dose of lime and alum reduced BOD, TSS, and TDS to a maximum of 85%, 98% and 77%, respectively. The combination of coagulation/precipitation gave enhanced COD removal with minimal sludge produced. (author)