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  • Author or Editor: M. Iqbal x
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The reduction in seed germination and seedling growth varies with plant species, salinity level and ionic composition of the salts present in soil solutions. Seed germination of Leucaena leucocephala and Prosopis juliflora were affected in soil extract of all halophytic communities. Significant (p < 0.05) reduction in seed germination of Thespesia populnea was found in soil extract of Cressa-Suaeda-Atriplex and Suaeda-Heliotropium-Tamarix community. The root growth of P. juliflora was significantly reduced in soil extract of Haloxylon-Suaeda-Atriplex community. Significant inhibition in shoot growth of L. leucocephala and P. juliflora were found in soil extract of Haloxylon-Suaeda-Atriplex community. L. leucocephala and T. populnea showed low tolerance in soil extract of Cressa-Suaeda-Atriplex community. P. juliflora demonstrated low tolerance in soil extract of Haloxylon-Suaeda-Atriplex community. The soil collected from different community showed variation for soil conductivity and cations. The highest sodium (11,500 µg/g) was observed in Suaeda-Heliotropium-Tamarix community. Salsola-Fagonia- Zygophyllum community exhibited the lowest concentration of sodium and potassium, 500 and 75 µg/g, respectively. It was found that sodium was directly proportional to the conductivity of the soil extract.

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Studies were conducted to measure the effect of irradiation treatment on thermoluminescence (TL) values in dried fruits such as apricots, dates and raisins. For this purpose, inorganic dust particulate (minerals) adhering to the fruit surface was collected from untreated and treated (0.5, 1.0 and 1.5 kGy) samples. The TL responses of the isolated minerals was measured in the temperature range of 80–320°C at an increasing rate of 10°C/s. It was observed that peak of the TL signals appeared at 200°C in each case and generally the magnitude of the peak signals was almost 103 times that of unirradiated samples. Regression and correlation analysis of the data indicated strong relationship between radiation absorbed dose and TL values at each temperature (r≥0.98). It was concluded that TL measurements could serve as a fast and reliable method for distinguishing as well as determining absorbed dose in irradiated dried apricot, date and raisin.

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Estimation of strontium has been studied by wavelength dispersive X-ray fluorescence spectrometery (WDXRF) as an analytical technique using Sr K as an analytical line. Lower limits of detection, precision, and intensities were plotted against counting time and concentrations to assess optimum time for measurement, expected scatter of the results, and calibration curves for intensity to concentration relationship. For its assessment the best equations determined by regression and least squares fitting along with a standard multiple addition technique were applied to a complex fuel admixture and simulated nuclear fuel solutions at a bum up of 650 GJ/Kg after a 0.5-year cooling time.

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The effect of gamma-radiations on bilirubin, in vitro, has been studied. It was found that gamma-radiation causes oxidation of bilirubin to biliverdine as one of the products. The likely implication of this effect in transformation of bilirubin to excretable products, in vivo, in case of jaundice is discussed.

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Mechanisms involved in salt tolerance urge exploration and investigation of genotypic variation to assist future breeding programs. Comparative examination of ten wheat cultivars for salt tolerance and their response towards proline-seed-priming was performed. Exposure of wheat seedlings to salinity resulted in prominent reduction in root and shoot growth attributes of all cultivars. Furthermore, decrease in the chlorophyll contents was evident although this varied among cultivars. Wheat seedlings grown from proline pre-treated seeds exhibited improved photosynthetic pigments, besides this response was also cultivar and concentration dependent. Generally, salt stressed plants exhibited higher antioxidant enzyme activities. Proline priming significantly influenced antioxidant activities, however, its magnitude varied. The peroxidase activity varied among wheat cultivars that were evident from the analysis of POD activity on Native-PAGE gel. Salinity caused the accumulation of Na+ in the roots and the magnitude of Na+ translocation to the shoot was cultivar dependent. Similarly, K+ uptake and its distribution among root and shoot varied. Priming treatments affected ion distribution of Na+ and K+ but inter-cultivar variations were evident. Conclusively, all the cultivars investigated exhibited differential response to salinity and proline seed pre-treatments. However, the proline-priming mediated improvements in growth and antioxidant enzyme activities contributed to stress tolerance which partly relied on the ability of the plant to uptake sodium and its partitioning in the roots. Of the cultivars tested, Faisalabad-08 and Bhakhar-2002 were ranked as relatively salt tolerant and the cvs. AARI-10, MH-97 and Auqab-2000 as relatively salt sensitive.

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A tetradentate set of N2O2 salicylaldehyde-amine-N-dione Schiff base was prepared by condensation with salicylaldehyde, ethylenediamine, 2,4-dione and reduction with NaBH4. The ligand system was characterized by 1H-NMR and FT-IR spectroscopy and HPLC. Radiolabeling studies of the 99mTc-complex were performed using stannous ions as the reducing agent. The purity of the complex was determined by ascending solvent system on paper chromatography and instant thin-layer chromatography (ITLC). The yield of the complex was >90%. Biodistribution of the 99mTc-complex of the precursor was studied in rabbits. A significant uptake and retention of injected activity was observed in the liver and cleared through the bladder. A faint activity was also observed in kidneys. These results indicate that the proposed system may be suitable for development of a liver/spleen imaging agent for future clinical applications.

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Transport of99mTc across tri-n-butylphosphate (TBP) kerosene oil supported liquid membranes (SLM) has been studied under various conditions. Presence of dichromate ions helps avoid activity scavenging effects. Concentration increase of TBP, the complexing carrier used in the present study has a positive effect on flux (J) and permeability (P) of these ions, as up to 2.87M there is an increase in J and P values. HCl concentration in the feed solution increases J and P with their maximum values at 2.5–3.0M HCl in the feed. Above this concentration there is a decrease in flux and permeability of99mTc(VII) ions. The given ions are stripped with LiCl or NaCl solutions but more with NaOH. The optimum conditions of transport of the given ions are 2.5M HCl concentration in the feed, 2.87M TBP concentration in the membrane and 1M NaOH concentration in the strip solution. Equations have been developed to indicate the relation between flux, J, viscosity, of TBP in organic membrane phase, temperature, T, [H+], in the aqueous feed solutions and Tc ion concentration in the feed solution. Based on P, the values determined from liquid membrane experiments, the quantitative flux values of Tc(VII) ions were also determined as a function of TBP concentration in the membranes, and HCl and Tc concentration in the feed solution using the given equations. This experimental technique provides quantitative results from trace level activity transfer experiments.

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Rice germplasm comprising wild species, low land and upland genotypes and 7 progenies of their inter-specific hybrids were tested under water levels of field capacity (100% moisture) and 75, 50 and 25% of field capacity. The objectives were to identify i) most water stress tolerant genotype, ii) characters associated with that genotype and iii) its ability to contribute water deficiency tolerance to lowland rice varieties. Experiment was conducted in potted soil with Randomized Complete Block two-factor factorial design and three replications. Different growth parameters were studied at tillering stage. Within an entry, reduction due to water level was significant in all the parameters. The interaction between various water levels and rice entries was also highly significant. We observed six parameters (shoot length, root length, shoot and root dry weight, number of tillers and leaf area) that were comparatively less affected in some of the progenies such as WAB-56-50 (shoot dry weight and root length), WAB-56-104 (root dry weight and tillers), WAB-272-H3 (leaf area) and WAB-272-H2 (shoot length) when tested under water level which is only 25% of the field capacity. This indicated that using these progenies as donor; water deficiency tolerance in lowland rice cultivars can be improved.

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Palladium nanoparticles (Pd-NPs) were prepared by a single-phase reduction of palladium acetate in the presence of different organic thiol ligands. Sizes, size distributions and crystallinity of the Pd-NPs were determined by high resolution transmission electron microscopy (HR-TEM) and powder X-ray diffraction (XRD) while thermogravimetric analysis coupled with mass spectroscopy (TGA-MS) was employed to measure their organic ligand to palladium ratios and to quantify contaminants. No systematic effect of the different ligands on the size and purity of the Pd-NPs was observed but 1st-generation Frechet dendron thiols had an about 4 times larger foot-print at the surface of the NPs than the other thiol ligands.

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Neutron induced radiography has been applied to the determination of boron concentrations in drinking water, collected from natural springs of Reshian and Muzaffarabad areas of Azad Kashmir, Pakistan, using CR-39 etched track detectors. The technique is based upon the simultaneous irradiation with thermal neutrons of a sample of unknown concentration and a standard of known boron concentration, fixed on a track detector. The subsequent counting of alpha and 7Li tracks in the detector resulting from the 10B(n,)7Li nuclear reaction is done after chemical etching. Boron concentration in the sample is determined by comparing 7Li and alpha-particle track density with that of a standard of known boron concentration. Boron concentrations in drinking water samples from Muzaffarabad and Reshian area of Azad Kashmir have been found to vary from (0.054±0.001) mg/l to (0.250±0.004) mg/l with an average of (0.16±0.002) mg/l. The observed concentration of boron in drinking water has been found to be less than the provisional Maximum Acceptable Concentration level (0.4 mg//l) of WHO. The drinking water from the reported area has been found to be within safe limits as far as boron related health hazards are concerned.

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