1,423 research outputs found
Influence of Growth Regulators and Explant on Plant Regeneration in Tomato
Influence of different growth regulators was studied on in vitro growth and regeneration of tomato (Solanum esculentum) explants derived from hypocotyls and cotyledons of aseptically grown seedlings. On the basis of regeneration frequency, number of shoot primordia and shoots produced per explants, it is concluded that the best regeneration is achieved on Murashige and Skoog (MS) medium supplemented with 0.5 mg L"1 of indole-3-acetic acid and 1.0 mg L"1 zeatin. In all the genotypes studied, a good percentage of regeneration frequency was observed in hypocotyl explants used
Morphological and Biochemical Characterization of Chrysanthemum
Ten large flowered chrysanthemum cultivars, viz., 'Beat Rice May', 'Beauty', 'Casa Grande', 'Jet Snow', 'John Weber' , 'Miss Maud Jeffries', 'Penny Lane', 'Shanker Dayal', 'Snow Ball' and 'S.S. Arnold' from National Botanical Research Institute (NBRI), Lucknow, were evaluated for morphological and biochemical characterization. Morphological data were recorded on vegetative and floral characters. Biochemical characterization included analysis of anthocyanins, carotenoides, chlorophyll content (chlorophyll a, b and total) and flavonoids. Results on morphological and biochemical parameters clearly indicated distinctness among cultivars with reference to differences in morphological characters and chemical composition of pigments
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Development of low cost packaged fibre optic sensors for use in reinforced concrete structures
There is an ongoing need to measure strains in reinforced concrete structures more reliably and under a range of circumstances e.g. long term durability (such as effects of cracking and reinforcement corrosion), response to normal working loads and response under abnormal load conditions. Fibre optic sensors have considerable potential for this purpose and have the additional advantages, including of immunity to electromagnetic interference and light weight (Grattan et al., 2000). This is important in railway scenarios and particularly so when the lines are electrified. Their small size allows for easy installation. However, their use as commercial ‘packaged’ devices (traditionally seen as necessary to achieve adequate robustness) is limited by their high cost relative to other sensor devices such as encapsulated electric resistance strain gauges. This paper describes preliminary work to produce a cost-effective and easy-to-use technique for encapsulating fibre optic sensors in resin using 3D printing techniques to produce a robust, inexpensive ‘packaged’ sensor system suitable for use with concrete structures. The work done to date has shown this to be a convenient and economical way of producing multiple sensors which were suitable for both surface mounting and embedment in reinforced concrete structures. The proof-of-concept testing to which the trial packages were subjected is described in the paper and the results indicate that 3D printed packages have considerable potential for further development and use in a variety of civil engineering applications, competing well with more conventional sensor systems
Effect of Gamma Irradiation on African Marigold (Tagetes erecta L.) Cv. Pusa Narangi Gainda
Seeds of African marigold cv. 'Pusa Narangi Gainda' were irradiated with 0, 100, 200, 300 and 400 Grays of gamma rays to induce mutation. Seeds were sown just after irradiation and 30-day old seedlings were transplanted into beds. Reduction in survival percentage, plant height, number of branches, leaf number, leaf size, plant-spread, stem diameter, increased foliage and floral abnormalities were observed upon irradiation and with increase in dose of gamma rays. LD50 was determined on survival basis. Leaf abnormality manifested itself as leathery texture of leaf, enhanced and irregular leaf thickness, asymmetric development of pinnate leaflets, reduction in pinnae number, chlorophyll variegation, pale and deep green leaves, narrow leaves and small leaves. Percentage of abnormal leaves and plants increased with increase in dose of gamma rays. Fasciation of stem was a common abnormality observed in all the treatments. Days to bud initiation, earliness in colour-appearance and days to full bloom were all significantly delayed upon exposure to gamma rays. Flower-head size, height and weight were highest at the lowest dose. Number of ray florets and size (length and width) decreased with increasing radiation dose. Floral abnormalities and % of plants with abnormal flower-heads increased with increasing dose of gamma irradiation. Floral abnormality included fasciation of flower-head and asymmetric development of ray florets. Stimulating effect of gamma irradiation was observed at 100 Grays where almost all the characters studied showed positive correlation, including growth and yield attributes. It is concluded that exposure to 100 Grays of gamma rays in African marigold cv. Pusa Narangi Gainda results in higher yield and marketable bloom
A study of the variability in the fish catches taken by successive hauls in the inshore waters off Calicut
One of the problems undertaken for investigations at the Calicut Sub-Station
of the Central Marine Fisheries Research Station when it was established
in May 1948, was a study of the fish populations of the inshore area near
Calicut with a view to ascertaining the species of fishes caught from the area,
their fluctuations and behaviour. This study necessitated periodical sampling
of the populations. The fact that most of the fishes occurring in the
inshore waters would be pelagic in nature introducing mobility and mixture
was anticipated. The idea of this' study was to find out whether a limited
number of sample hauls from such a mobile population would help to know
the composition of such a population with a specified degree of accuracy.
This needed the study of the variability obtained in the species composition
obtained in the catch of successive sample hauls. With this view, four series
of sampling trials were conducted over a period of one month and the result
of analyses of these trials is given in this communication
Superrevivals in the quantum dynamics of a particle confined in a finite square well potential
We examine the revival features in wave packet dynamics of a particle
confined in a finite square well potential. The possibility of tunneling
modifies the revival pattern as compared to an infinite square well potential.
We study the dependence of the revival times on the depth of the square well
and predict the existence of superrevivals. The nature of these superrevivals
is compared with similar features seen in the dynamics of wavepackets in an
anharmonic oscillator potential.Comment: 8 pages in Latex two-column format with 5 figures (eps). To appear in
Physical Review
Coherent states of P{\"o}schl-Teller potential and their revival dynamics
A recently developed algebraic approach for constructing coherent states for
solvable potentials is used to obtain the displacement operator coherent state
of the P\"{o}schl-Teller potential. We establish the connection between this
and the annihilation operator coherent state and compare their properties. We
study the details of the revival structure arising from different time scales
underlying the quadratic energy spectrum of this system.Comment: 13 pages, 6 figure
Multifaceted contributions : health workers and smallpox eradication in India
Smallpox eradication in South Asia was a result of the efforts of many grades of health-workers. Working from within the confines of international organisations and government structures, the role of the field officials, who were of various nationalities and also drawn from the cities and rural enclaves of the countries in these regions, was crucial to the development and deployment of policies. However, the role of these personnel is often downplayed in official histories and academic histories, which highlight instead the roles played by a handful of senior officials within the World Health Organization and the federal governments in the sub-continent. This article attempts to provide a more rounded assessment of the complex situation in the field. In this regard, an effort is made to underline the great usefulness of the operational flexibility displayed by field officers, wherein lessons learnt in the field were made an integral part of deploying local campaigns; careful engagement with the communities being targeted, as well as the employment of short term workers from amongst them, was an important feature of this work
The spectral energy distribution of the redshift 7.1 quasar ULAS J1120+0641
We present new observations of the highest-redshift quasar known, ULAS
J1120+0641, redshift , obtained in the optical, at near-, mid-, and
far-infrared wavelengths, and in the sub-mm. We combine these results with
published X-ray and radio observations to create the multiwavelength spectral
energy distribution (SED), with the goals of measuring the bolometric
luminosity , and quantifying the respective contributions from the
AGN and star formation. We find three components are needed to fit the data
over the wavelength range m: the unobscured quasar accretion
disk and broad-line region, a dusty clumpy AGN torus, and a cool 47K modified
black body to characterise star formation. Despite the low signal-to-noise
ratio of the new long-wavelength data, the normalisation of any dusty torus
model is constrained within . We measure a bolometric luminosity
ergs, to which the three components contribute
, respectively, with the remainder provided by the extreme UV
m. We tabulate the best-fit model SED. We use local scaling
relations to estimate a star formation rate (SFR) in the range /yr from the [C] line luminosity and the
m continuum luminosity. An analysis of the equivalent widths of the
[C] line in a sample of quasars suggests that
these indicators are promising tools for estimating the SFR in high-redshift
quasars in general. At the time observed the black hole was growing in mass
more than 100 times faster than the stellar bulge, relative to the mass ratio
measured in the local universe, i.e. compared to , for ULAS J1120+0641 we measure .Comment: Accepted for publication in A&A. 10 pages, 5 figures, 5 table
General relativistic plasma in higher dimensional space time
The well known (3+1) decomposition of Thorne and Macdonald is invoked to
write down the Einstein-Maxwell equations generalised to (d+1) dimensions and
also to formulate the plasma equations in a flat FRW like spacetime in higher
dimensions (HD). Assuming an equation of state for the background metric we
find solutions as also dispersion relations in different regimes of the
universe in a unified manner both for magnetised(un) cold plasma. We find that
for a free photon in expanding background we get maximum redshift in 4D
spacetime, while for a particular dimension it is so in pre recombination era.
Further wave propagation in magnetised plasma is possible for a restricted
frequency range only, depending on the number of dimensions. Relevant to point
out that unlike the special relativistic result this allowed range evolves with
time. Interestingly the dielectric constant of the plasma media remains
constant, not sharing the expansion of the background, which generalises a
similar 4D result of Holcomb-Tajima in radiation background to the case of
higher dimensions with cosmic matter obeying an equation of state . Further,
analogous to the flat space static case we observe the phenomenon of Faraday
rotation in higher dimensional case also.Comment: 17 pages, 3 figure
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