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Search Results: 1 - 10 of 400842 matches for " M. Hanif "
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Diagnostic Study of Nickel Plasma Produced by Fundamental (1064 nm) and Second Harmonics (532 nm) of an Nd: YAG Laser  [PDF]
M. Hanif, M. Salik, M. A. Baig
Journal of Modern Physics (JMP) , 2012, DOI: 10.4236/jmp.2012.330203
Abstract: In the present work, we have studied the spatial evolution of the nickel alloy plasma produced by the fundamental (1064 nm) and second (532 nm) harmonics of a Q-switched Nd: YAG laser by placing the target material in air at atmospheric pressure. The four Ni I lines at 335.10 nm, 394.61 nm, 481.19 nm and 515.57 nm are used for the determination of electron temperature (Te) using Boltzmann plot method. The electron temperature is calculated as a function of distance from the target surface for both modes of Nd: YAG laser. In case of fundamental (1064 nm) mode of laser, the temperature varies from 13700 - 10270 K as the distance is varied from 0 to 2 mm. Whereas, in the case of second (532 nm) mode of laser it varies from 13270 - 9660 K for the same distance variation. The electron temperature has also been determined by varying the energy of the laser from 90 to 116 mJ, for the fundamental (1064 nm) harmonic and from 58 to 79 mJ for the second (532 nm) harmonics of the laser. The temperature increases from 14192 to 15765 K in the first case and from 13170 to 14800 K for the second case. We have also studied the spatial behavior of the electron number density in the plasma plume. The electron number density (Ne) in the case of fundamental (1064 nm) harmonic of the laser having pulse energy 125 mJ varies from 2.81 × 1016 to 9.81 × 1015 cm-3 at distances of 0 mm to 2.0 mm, whereas, in the case of second (532 nm) harmonic, with pulse energy 75 mJ it varies from 3.67 × 1016 to 1.48 × 1016 cm-3 for the same distance variation by taking Ni I line at 227.20 nm in both the cases.
A Comparison Of The Effect Of NaCl On The Cell Doubling Time Of The Root Apical Meristem In Triticum aestivum (cvs. Lyallpur 73, Pak 81 and Lu-26-S)
M. Hanif,M. S. Davies
Pakistan Journal of Biological Sciences , 1998,
Abstract: The Pakistan wheat cultivars investigated exhibited different cell doubling times not only at the control but they also differed in response to increasing the NaCl concentration. The rates of metaphase accumulation of the cultivars were very slow and thus cell doubling times were very long. This may be a reflection of very slow mitotic activity in root meristems.
Mitotic Activity in the Root Apical Meristems of Secale cereale (cv. K2) and Triticum aestivum (cvs. Chinese spring, Lyallpur 73, Pak 81, Lu-26-S and Sandal) Under Elevated NaCl Treatment.
M. Hanif,M. S. Davies
Pakistan Journal of Biological Sciences , 1998,
Abstract: A 8 day exposure to NaCl reduced the Mitotic indices in the root meristems of all the cultivars in aerated solution culture. There were large differences between the cultivars in the control solutions. The relative frequency of prophase and metaphase in Mitotic cells decreased with increasing NaCl concentration while the relative frequency of anaphase and telophase increased. The mitotic index in the root meristem of Chinese spring was reduced to a greater extent than in K2 cultivar.
Effects of NaCl Induced Stress on the Mitotic Cell Cycle and Growth Fraction in the Root Meristems of Root Tip Cells in Two Lines of Barley
M. Hanif,M. S. Davies
Pakistan Journal of Biological Sciences , 1999,
Abstract: The seeds of Hordeum sativum lines B-88079 and B-jou87 were grown in aerated 0.1 Rorison nutrient solution for 72 hours. Then the kinetics of cell cycle in the root meristem were determined by a pulse labelling experiment with low specific activity tritiated thymidine following a 70 hours exposures to three concentrations of NaCl (0,50, 100 mM NaCl). Hordeum sativum lines B-jou87 had a longer cell cycle duration than that of line B-88079. The mitotic cell cycle in line B-88079 remained unaffected at 50 and 100 mM NaCl concentrations but that of B-jou87 was decreased. The growth fraction (refers to percentage of meristematic cells which are actively cycling as opposed to these that are not cycling in the meristem) was not determined due to non labelling of any cells in continuos labelling experiment.
Effects of NaCl on Meristem Size and Proximity of Root Hairs to the Root Tips in Triticum aestivum (cvs. Lyallpur-73, Pak-81 and Lu-26-S)
M. Hanif,M. S. Davies
Pakistan Journal of Biological Sciences , 1998,
Abstract: Seedlings of Triticum aestivum cvs. Lyallpur-73, Pak-81 and Lu-26-S were grown in solution culture at varying concentrations of NaCl for 8 days. Increasing concentrations of NaCl reduced the size of apical meristem and caused the most distal root hair to form closer to the root tip in all the cultivars. Although the position of the first root hair from the root cap boundary was reduced by salinity, yet there were comparatively little differences between these Pakistani Wheat cultivars in response to NaCl, thus in these studies the relative positions of root hairs is not a good discriminating character for assessing the salt tolerance.
Effects of NaCl on Meristem Size and Proximity of Root Hairs to the Root Tips In Secale cereale (cv. K2) and Triticum aestivum (cv. Chinese spring)
M. Hanif,M. S. Davies
Pakistan Journal of Biological Sciences , 1998,
Abstract: A 8 day exposure to NaCl reduced the length of root apical meristem in Secale cereal (cv. K2) to a greater extent than Triticum aestivum (cv. Chinese Spring). NaCl induced also root hair formation much closer to the root cap boundary than in the control roots. Contrasting cultivars were differentially sensitive by NaCl in respect of distance of the first root hair from the root cap boundary in root meristem and this may be used as a character for screening genotypes at the seedling stage for variability in NaCl tolerance.
The Influence of NaCl on the Cell Cycle and Growth Fraction in the Root Meristems of Triticum aestivum cvs. Lyallpur 73 and Lu-26-S
M. Hanif,M. S. Davies
Pakistan Journal of Biological Sciences , 1998,
Abstract: The seedlings of Triticum aestivum cvs. Lyallpur 73 and Lu-26-S were grown in aerated 0.1 Rorison nutrient solution for 72 hours. Then the kinetics of ells cycle in the root meristem were determined by a pulse labelling experiment with low specific activity tritiated thymidine following a 70 hours exposures to three concentrations of NaCl (0,30, 70 mM NaCl). Treatments with 30 and 70 mM NaCl increased the length of cell cycle in cv Lu-26-S but that of Lyallpur 73 was decreased. The growth fraction (refers to percentage of meristematic cells which are actively cycling as opposed to these that are not cycling in the meristem) was increased in Lyallpur 73 from 7.9 to 11.11% over the range of 0-70 mM NaCl whereas that of Lu-26-S was decreased in response to increasing NaCl concentration.
Studies on the Effects of Salt on Seed Germination in Contrasting Cereal Cultivars
M. Hanif,M. S. Davies
Pakistan Journal of Biological Sciences , 1998,
Abstract: Osmotic and specific effect are the most frequently mechanisms by which saline substrates reduce plant growth. However, the relative importance of osmotic and specific ion effect on plant growth seems to vary depending on the drought and/or salt tolerance of the plant under study. The object of this work was to compare the relative salt tolerance of differentially salt-tolerant cultivars of wheat, rye and barley grown at varying concentrations of NaCl in solution culture during germination. Increasing concentration of NaCl (60-150 mM) reduced the percentage of seed germinating but a lower concentration (0-60 mM) inhibited the root growth of the cultivars suggesting seedling growth to be more sensitive than germination. The lines of Barley (Hordeum sativum) were generally less sensitive to the NaCl-induced reduction in respect of the character than Wheat(Triticum aestivum) or Rye (Secale cereale). The proportion of seeds germinating was not a good discriminating character for assessing the salt tolerance of these cultivars in these studies.
Effect of Zn(II) deposition in soil on mulberry-silk worm food chain
M Ashfaq, W Afzal, MA Hanif
African Journal of Biotechnology , 2010,
Abstract: The present study was conducted to evaluate the entrance of Zn(II) into the food chain of Bombyx mori (silk worm) from mulberry plants irrigated using Zn(II) containing synthetic effluents. The soil, plant, silkworm and their excreta were sampled to determine Zn(II) amount by using atomic absorption spectrometry (AAS). The amount of Zn(II) deposited by synthetic effluent to soil was increased with pH of the effluent. However, the bioaccumaltion of Zn(II) in Morus alba leaves and B. mori larvae was high when the effluent pH was in the acidic range. B. mori excreted considerable amount of Zn(II) but still most of Zn(II) resided inside its body. The maximum Zn(II) amount detected in soil, leaves, larvae and faeces were 386.51 ± 0.03, 142.85 ± 0.001, 91.375 ± 0.019 and 42.13 ± 0.69 mg/kg, respectively. Zn(II) present in B. mori body was responsible for toxic effects on its life cycle. First instar of B. mori was most affected by Zn(II) toxicity. Body length, body weight of B. mori decreased with increase in bioaccumlated Zn(II) amount in larval body. Higher Zn(II) concentration in larval body increased B. mori death rate significantly.
Application of Mating Disruption Approach to Control Codling Moth (Cydia pomonella L.) Damage to Apple Crops in Azad Kashmir, Pakistan
M. Ashraf,M. Asif,M. Adrees,Wajahat Hanif
Pakistan Journal of Biological Sciences , 2007,
Abstract: Various techniques are applied to control the pest damage to (pome) crops in different countries of the world. Among the integrated pest management programmes (IPCP), mating disruption (MD) approach has its own advantages over pesticide techniques being less hazardous to environment. An exhaustive systematic field trial surveys were conducted to explore the seasonal activities of Codling Moth (CM) Cydia pomonella under natural conditions and the (MD) method was applied to Control Maling Disruption (CM) damage to apple (pome) crops in area of Azad Jammu and Kashmir, (Pakistan). Mating Disruption (MD) technique offers several advantages over pesticide sprays methods and, MD reduces CM damage. The present study describes the assessment of time of pest infestation, peak flight temporal and spatial variation of CM (Cydia pomonella) in two different experimented habitats by the use of pheromone trap approach. For experimental data, two distinct flight periods of CM were recorded, suggesting two generations per year. The pest population density was observed to be the highest in the first weeks of May and July. It was concluded that by application of the MD technique a better growth of pome crops can be obtained. Hence, for sustainable and comprehensive fruit farming, a more widespread use of pheromones technique (Mating Disruption- MD) may be useful step to enhance the agricultural yield of apple (pome) crops
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