399 research outputs found
ZONE CENTRE PHONON MODE BEHAVIOUR OF CUBIC AND WURTZITE PHASE OF TERNARY InxGa1-xN
The group-III nitrides have been acknowledged as notable materials for researchers in recent times because of their extra ordinary properties and applications. The fundamental property of these materials is their wide and direct band gap, which can also be tailored by doping. A common characteristic of these device structures is the applicability of their ternary alloys. Despite of the broad range of the ternary alloys of these group-III nitrides only some have been discussed. So in this study, zone centre phonon mode behavior of the ternary alloy InxGa1-xN in both phases (cubic and wurtzite phase) has been studied and with the use of de Launey angular force constant model. The various optical phonon modes at zone centre have been calculated for both phases of InxGa1-xN. The content of Ga and in alloy is in the range 0<x<1. The one mode behavior has been found for both phases of the alloy and it is found that for InxGa1-xN continuous decreases in magnitude of phonon frequency with the increase in the content of In which is due to the fact that frequency varies inversely proportional to the mass, as content of In increases mass of alloy increases
Genetic variability and relationship analysis of Bipolaris sorokiniana isolates causing spot blotch disease in wheat using random amplified polymorphic DNA (RAPD) markers
Twelve (12) isolates of Bipolaris sorokiniana (Cochliobolus sativus) of wheat were studied for their molecular characterization using random amplified polymorphic DNA (RAPD) techniques. Twenty (20) RAPD primers were tested for amplification of the genomic DNA of fungal isolates of wheat. A total of 77 bands were amplified, out of which 68 bands were polymorphic showing high range of variability (84.42% polymorphism) and nine bands were monomorphic. Average total number of bands generated per primer was 3.85, of which 3.4 and 0.45 were polymorphic and monomorphic, respectively. The genetic similarity coefficients for the 12 isolates of B. sorokiniana of wheat ranged from 0.526 to 0.842. The highest similarity occurred between DWR-Karnal versus Hisar-PBW-443 and Hisar-502 versus IARI with a coefficient value of 84.2% and the lowest similarity occurred between two fungal isolates that is, Hisar-WH-542 versus IARI and Meerut-Hallana versus Faizabad with a coefficient value of 52.6%. The study indicates that the RAPD is a good tool for determination of genetic variability and relationship of B. sorokiniana, which is already visible in the analysis of even such a small number of isolates.Keywords: Wheat, Bipolaris sorokiniana, genetic variability, polymorphism, random amplified polymorphic DNA (RAPD) markerAfrican Journal of Biotechnology Vol. 12(19), pp. 2526-253
Evaluation of genetic diversity in rice using simple sequence repeats (SSR) markers
The genetic diversity of 64 rice genotypes using 20 SSR primers on chromosome number 7-12 was investigated. DNA was extracted by modified cetyl trimethyl ammonium bromide (CTAB) method. The banding pattern was recorded in the form of 0-1 data sheet which was analyzed using unweighted pair group method with arithmetic mean (UPGMA) based on Jaccard's similarity coefficient. The results revealed that out of twenty, eight primers showed distinct polymorphism, indicating the robust nature of microsatellites in revealing polymorphism. The cluster analysis showed higher level of genetic variation among the genotypes. Similarity coefficients ranged from 0.40 to 0.96. The dendrogram revealed 8 major distinct clusters. Higher range of similarity values for related genotypes using simple sequence repeats (SSR) provides greater confidence for the assessment of genetic diversity and relationships. The polymorphism information content (PIC) value for the SSR loci ranged from 0.36 to 0.98. Higher PIC values were associated with higher level of polymorphism. The information obtained from the DNA fingerprinting studies helps to distinctly identify and characterize the various genotypes. Such information can be used in background selections during backcross breeding programs.Key words: Genetic diversity, simple sequence repeats (SSR) marker, dendrogram
Utilizing Composted Jatropha & Neem cake and Tobacco Waste to sustain Garlic yields in Indo-Gangetic plains
The effect of composted Jatropha de-oiled cake, neem de-oiled cake and tobacco waste on morphological parameters like maximum leaf length, number of leaves, fresh and dry weight of bulb and yield was studied for Garlic (Allium sativum L.). Trials were conducted on field plots under the RBD design. The parameters recorded for plants grown on soil treated with composted organic fertilizer treatments were compared to those recorded for plants grown on chemical fertilizer treated soil and control. The results showed that the application of 2 tones per hectare mixture of composted Jatropha cake and tobacco waste (in ratio 2:1) resulted in an increase of 22.88 % in fresh bulb weight, 29.52% in dried bulb weight per plant and 18.3% in average yield of bulb as compared to control. This yield enhancement was significantly higher than control and comparable to that recorded for plants grown on soil treated with chemical fertilizers. The significant increase in garlic yield on application of composted Jatropha cake and tobacco waste is due to the availability o
Ethno-Medicinal, Phytochemical and Antimicrobial Studies of Euphorbia tirucalli L.
SUMMARYPresent study exposed various claims about the medicinal properties of Euphorbia tirucalli L., used by the indigenous people of Rajasthan to cure rheumatism, Skin disorders, Cough and other ailments. This plant was assessed for ethnopharmacological screenings, phytochemical analysis and antimicrobial screenings which also include anti-HIV activity, so as to validate the efficacy of indigenous herbal medicine. In the present study antimicrobial activity of the crude alcoholic extracts of leaf and stem of E. tirucalli against the known enteric pathogens was carried out. Anti-HIV screening activity was carried out using HIV Protease colorimetric Assay. Low MIC exhibited by the extract against S. aureus is of great significance in the healthcare delivery system, since it could be used as an alternative to orthodox antibiotics in the treatment of infections caused by these microbes, especially as they frequently developing resistance to known antibiotics. Key words: Alkaloids, Triterpenes, Antimicrobial activity, anti-Carcinogenic, Anti-HIV Bhuvaneshwar Upadhyay et al. Ethno-Medicinal, Phytochemical and Antimicrobial Studies of Euphorbia tirucalli L.  J. Phytol 2/4 (2010) 65-77
Pharmacognostical and Antibacterial Studies of Different Extracts of Euphorbia hirta L.
SUMMARYLeaves of Euphorbia hirta, traditionally practiced in the treatments of boils, dysentery, enteritis and various skin conditions, were extracted by soxhlet extraction in various extraction mediums. The disc diffusion method was used to determine the antibacterial activity against many Gram positive and Gram negative bacteria (Standard strains and clinical isolates). Antibacterial sensitivity test indicated that the methanolic extract inhibited the growth of S. aureus, E. coli, and B. subtilis to varying extents while K. pneumonia was the most resistive strain to these extracts. Minimum inhibitory concentration (MIC), of the extract against E. coli, S aureus, and S. entertidis were in the range of 0.1mg/ml. Phytochemical analysis indicates presence of terpenes, tannins, alkaloids and flavonoids which might be accountable for its antimicrobial properties, and these results validate the traditional uses of the plant in the treatment of various diseases.Bhuvaneshwar Upadhyay et al. Pharmacognostical and Antibacterial Studies of Leaf Extracts of Euphorbia hirta L. J Phytol 2/6 (2010) 55-6
Hydrogen induced resistance and optical transmittance of pulsed laser deposited Pd/Mg thin films
The hydrogen detection is an important issue for the societal acceptance of H2 as energy carrier. In present research work, we have investigated hydrogen sensing and optical properties of Pd/Mg thin films on glass substrate deposited by pulsed laser (PL). As-deposited thin films have been exposed (hydrogenation) to H2 gas (2 bar) at room temperature in a hydrogenation unit. Hydrogenated and dehydrogenated (at different temperatures) samples have been characterized using X-ray diffractometer (XRD), field-emission scanning electron microscopy (FE-SEM), UV-Vis-NIR spectrophotometer, atomic force microscopy (AFM). XRD results confirm the formation of hydride (MgH2) tetragonal phase upon hydrogenation of Pd/Mg films. Hydrogen induced resistance response of Pd/Mg films has been measured in-situ during hydrogenation/dehydrogenation process by using two- probe electrical method. The response time (sensitivity) of Pd/Mg films for hydrogen gas is ~ 60 s at room temperature. The study of optical transmittance of hydrogenated Pd/Mg films indicates their switchable mirror behavior
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