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Abstract  

Three Egyptian monazite samples from the beach black sand at Abou Khashba near Rosetta, submitted by the laboratories of the nuclear materials authority of Egypt were analyzed for elemental contents, using Prompt gamma ray neutron activation analysis (PGNAA) as an effective analysis technique especially for rare earth elements. An integrated system for PGNAA, located at hot Lab. Center, has proven useful for the analytical purpose using 252Cf neutron source with neutron flux of 6.16E7 n/cm2 s, that system has been designed and calibrated for PGNAA. Sensitivity curves using different standard concentration values of artificial liquid standards samples at different concentrations ranging from 1,000 to 5,000 mg/L in case of Sm and Gd, while from 100 to 1,000 mg/L for Eu, have been constructed. The average concentration values for Gd, Sm and Eu in the samples under investigation was at 1.46E4 ± 0.21, 6.683E4 ± 0.14 and 440 ± 0.18 ppm, respectively. A comparative study of the obtained results and the results of ICP-Ms was given.

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A pot culture experiment was conducted to study the influence of NH 4 Cl (AnalaR grade or commercial fertilizer) on soil pH and on the growth, yield and nutrient uptake of cotton (cv. NIAB-Karishma) grown in alkaline soil. The experiment was carried out in a net-house under natural conditions. The soil used was clayey loam with pH 8.61, and ammonium chloride either from commercial fertilizer or of AnalaR grade (both containing up to 25% N) was applied in three split doses, after germination (10 days), at the vegetative stage (40 days) and at the flowering stage (80 days) @ 6, 12 and 18 kg ha −1 . The application of NH 4 Cl decreased the soil pH and increased the plant height and cotton yield plant −1 . Plants treated with NH 4 Cl AnalaR grade produced higher yields as compared to NH 4 Cl commercial fertilizer. The uptake of micronutrients such as Fe, Cu, Zn and B was enhanced by NH 4 Cl application in both the stem and leaves of cotton. However, AnalaR grade NH 4 Cl proved more effective than NH 4 Cl commercial fertilizer in all cases.

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Abstract  

Water hyacinth (Eichhornia crassipes) is known to accumulate elements from rivers and a good tool for water monitoring. To test the usefulness of such an aquatic plant as a bioindicator, we have determined the levels of Na, Ca, Cr, Fe, Co, Zn, As, Rb, Zr, Sb, Cs, La, Ce, Nd, Sm, Eu, Tb, Yb, Hf, Ta, Th, and U in water hyacinth around industrial facilities and along the studied area by instrumental neutron activation analysis. The concentrations of Cr, Mn, Fe, Co, Ni, Cu, Zn, Mo, Cd, and Pb were determined in upstream river water and effluent factories. Contamination factor, and pollution load index was calculated. The results show that higher concentrations as well as bioaccumulation factors of these elements were observed in water hyacinth samples around the industrial facilities. On the other hand a decrease in calcium concentration was observed as a result of the thermal pollution of Nile river water. The pollution load index for the studied area was estimated to be 4.2.

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Application of salt stress (100 mM) through root growing medium caused a considerable decrease in plant fresh and dry biomass, maximum quantum yield (F v /F m ), chlorophyll contents, leaf water potential, and leaf Ca, K, P and N concentrations of two maize cultivars (Apex 836 and DK 5783). However, salt-induced increase was observed in leaf osmolality (LO), proline, hydrogen peroxide (H2O2), malondialdehyde (MDA), Na+ concentration and activities of enzymatic antioxidants, such as catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD). Of five humic acid (HA) levels used under non-stress and stress conditions in an initial experiment, 100 mg L−1 was chosen for subsequent studies. Exogenous application of humic acid (HA) at the rate of 100 mM as a foliar or pre-sowing seed treatment significantly increased the plant biomass, F v /F m , chlorophyll pigments and proline contents, while it considerably reduced the leaf water potential, H2O2 and MDA contents as well as the activities of all the afore-mentioned enzymatic antioxidants. Of both modes of exogenous treatment, foliar spray was better in improving plant biomass, chlorophyll contents, LO, leaf Na+ as well as the accumulation of all nutrients measured, however, in contrast, seed pre-treatment was more effective in altering leaf proline, H2O2 and MDA contents. Of both maize cultivars, cv. DK 5783 excelled in plant biomass, chlorophyll contents and leaf N, Ca and K concentrations as well as in the activities of all three antioxidant enzymes, whereas cv. Apex 836 was superior in leaf Na+ and P concentrations, H2O2 and MDA contents. Cv. DK 5783 was comparatively better in salt tolerance as compared to cv. Apex 836. Overall, exogenous application of HA was effective in improving salinity tolerance of maize plants which can be attributed to HA-induced increase in plant biomass, chlorophyll contents, mineral nutrients and activities of key antioxidant enzymes.

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Pollack Periodica
Authors:
Ammar Jalil Almosawi
,
Ashraf A. M. R. Hiswa
, and
Tawfek Sheer Ali

Abstract

Prying force formation at bolts is considered as an important problem in steel connection design. It affects the connection bearing capacity, ductility and serviceability negatively by increasing stresses induced inside connections. In the present work, behavior of steel connection under prying force is studied. A connection of steel beam-column has been modeled using software Revit program. Tension load is applied increasingly and the connection displacement has been measured until failure. Finite element simulation of steel angles under the effect of tension load and prying force has been studied. It is found that the connection has three phases of bearing behavior. Plastic hinge formation noticed increased with prying force presence.

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Alkaline and acidic pH of soil limit crop yield. Products of phenylpropanoid pathway play a key part in plant abiotic stress tolerance. It was aimed to assess efficacy of tyrosinepriming for activation of enzyme involved in phenolic accumulation induction of pH tolerance in maize seedlings. Seeds of two maize cultivars, namely Sadaf (pH tolerant) and S-2002 (pH sensitive), were grown under three pH levels (3, 7 and 11). Eight and twelve days old seedlings were harvested and parted into roots and shoots for the assessment of growth, enzymatic and non-enzymatic antioxidants. PAL activity was directly correlated with total soluble phenolics, flavonoids, growth and seedling vigour. Lower accumulation of phenolics and PAL activity in the pH sensitive (S-2002) cultivar indicated greater oxidative damage caused by pH extremes. Priming improved antioxidative potential by enhancing PAL activity and phenolics accumulation and hence increased growth in maize seedlings.

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A study was conducted on the sheep farm of the Livestock Experimental Station, located in the southwestern Punjab, Pakistan, to determine the copper nutrition status of different classes of grazing sheep during two different seasons. A complete free-choice supplement (feed) was available to all animals throughout the year. The purpose of this research was to investigate, as a function of the seasons, the transfer of Cu from soil, and dietary factors to sheep grazing in this semiarid region, in order to evaluate if the Cu requirement of grazing livestock was met or if a deficiency occurred. The final goal was to maximize the production of the animals by adopting, if necessary, adequate, balanced Cu supplementation. Soil, forage, feed and water samples, and animal samples (plasma, milk, faeces and urine from lactating ewes, plasma, faeces and urine from non-lactating ewes and plasma and faeces from male animals) were taken eight times during the year (four times in each season). Soil copper was affected by the seasonal changes and sampling intervals and was significantly higher than plant needs during both seasons, while the forage copper level did not show significant seasonal fluctuations, but was only affected by the sampling intervals. The soil and forage Cu was sufficient for the requirements of the plants and the animals grazing there on during both seasons. The copper contents of the feed and water showed no seasonal or sampling interval fluctuations. The plasma Cu was affected by seasonal variations in non-lactating ewes and in rams and by sampling intervals in the lactating ewes. Faecal and urine Cu was not affected by seasonal or sampling intervals except in non-lactating ewes, where the sampling interval had a pronounced effect on faecal Cu, while milk Cu in lactating ewes was affected by seasonal changes only. In all classes of sheep plasma Cu was higher during the winter than during the summer and remained in the normal range for ruminants during both seasons. It is concluded that a mixture with high bioavailability, containing Cu, should be continuously provided to grazing sheep in this semi-arid region in order to maintain the normal level of Cu and maximize the production potential of ruminants.

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Abstract

The influence of utilizing waste concrete aggregates on the flexural behavior of external reinforced concrete beams has been studied. Seven mixtures were prepared for this investigation where the concrete mixtures had different waste concrete percentages and admixtures. Also, seven beams were modeled by Ansys program and the properties of the seven mixtures have been used in the models to study their effects. It was found that using waste concrete aggregates has decreased the load bearing capacity and concrete ductility. It was found that the beam bearing capacity was decreased by 10.7% when using only waste concrete. Using admixtures have enhanced the concrete properties where the load capacity of beams has been increased by 39% when using silica fume and superplasticizer and the load capacity has increased by 44.6% when multi-admixtures have been used. Besides, it was found that using additives has enhanced the beam ductility significantly.

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Recently, super rice has gained much importance due to its high yield potential while exogenous application of plant growth regulators (PGRs) is an important aspect in plant development and defense responses under stress conditions. In this study we conducted two pot experiments. Firstly, four super rice cultivars, viz. Peizataifeng, Huayou 213, Yuxiangyouzhan and Huahang 31 were subjected to a series of five chilling temperatures, i.e. 11 °C, 12 °C, 13 °C, 14 °C and 15 °C (day/night) for about 25–27 days. Secondly, seeds of Peizataifeng (super rice) and Yuejingsimiao 2 (non-super rice) were then treated with different combinations of salicylic acid (SA), brassinolide (BR), calcium chloride (CaCl2) and fulvic acid (FA) and then exposed to chilling stress at 13 °C for four days. Resultantly, Peizataifen (super rice) was found with the lowest seedling survival rate at all chilling temperatures among all four super rice cultivars, however, it was still found more resistant when compared with Yuejingsimiao 2 (non-super rice) in the second experiment. Furthermore synergistic effect of all PGRs alleviated low temperature stress in both rice cultivars by improving seedling survival rates, leaf area, seedling dry weight, seedling height, root morphology and by modulating antioxidant enzymes, improving proline content and lowering lipid peroxidation.

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