1,639 research outputs found
Bianchi Type-I Wet Dark Universe in Bimetric Relativity
In this paper , we have investigated the role of Wet Dark Fluid in Bianchi Type-I cosmological model within the framework of bimetric theory of relativity proposed by Rosen N. Here we have used a new equation of state for the matter dark energy component of the universe known as Wet Dark Fluid given by = ?( - ) which can describe a liquid for example water. It is further observed the non existence of Wet Dark Fluid in bimetric relativity. Keywords: Bianchi Type-I Universe , Wet Dark Fluid , Bimetric Relativit
Role of rainfall in the breeding of Labeo rohita (Ham.), Cirrhinus mrigala (Ham.), Catla catla (Ham.), at Damdama (Haryana), a semi-arid zone
The role of several environmental factors on the breeding and hatching of fish has been studied by many earlier investigators. Perfection in the hypophysation technique has helped to some extent in by-passing the environmental variables such as temperature, light and rain. With the use of a modern fish hatchery, it is possible to attain maximum success in breeding and hatching, even without rains; reference is given to studies carried out regarding the role of rainfall in the breeding of Labeo rohita, Cirrhinus mrigala, Catla catla
Lepton distribution as a probe of new physics in production and decay of the t quark and its polarization
We investigate the possibilities of studying new physics in various processes
of t-quark production using kinematical distributions of the secondary lepton
coming from decay of t quarks. We show that the angular distributions of the
secondary lepton are insensitive to the anomalous tbW vertex and hence are pure
probes of new physics in a generic process of t-quark production. The energy
distribution of the lepton is distinctly affected by anomalous tbW couplings
and can be used to analyze them independent of the production process of t
quarks. The effects of t polarization on the distributions of the decay lepton
are demonstrated for top-pair production process at a gamma-gamma collider
mediated by a heavy Higgs boson.Comment: 15 pages, 7 figures, uses axodraw.sty (included), references added.
v3 to appear in Journal of High Energy Physics. Incorporates minor changes in
the discussion on radiative corrections which do not affect the results. Typo
in reference correcte
Selection of elite seedling clones of mango (Mangifera indica L.) exposed by phylogenetic relationship and morpho-taxonomic traits
Almost all the current commercial mango cultivars in India are the result of selection from the natural seedling population and majority of them have been selected by the farmers.The conventional breeding system with traditional knowledge is evolving more and more towards preservation of genetic diversity. In Pusa site of the UNEP/GEF sponsored project in the Bihar state of India, many mango seedlings are found growing in the orchards as well as in the backyards. Mango being a highly cross-pollinated fruit crop exhibits a lot of variability in morpho-physico-chemical traits of fruits in these seedling plants. For selection of the elite seedling genotypes, farmers play an important role and with the help of the breeder they can pave the way for maintaining the local germplasm. Hence, in order to study the genetic variability among mango seedlings and to select elite mango genotypes and to conserve them, a survey was conducted in the four project communities and the surrounding villages. A total of 74 seedling types of mango were characterized using morpho-taxonomic parameters. Physico-chemical characterization of fruit samples revealed the existence of a great variability in the seedling mango plants, which not only contributes to biological diversity, but can also be used for crop improvement or for varietal selection. Based on this physico-chemical characterization, principal component and cluster analysis and grouping of seedling clones on the basis of possession of desirable characters by them, six seedling clones, having the majority of desirable fruit characteristics were selected. These selected clones will definitely broaden the genetic base of mango in the Pusa site as well offer the scope for choice of selection of varieties by the farmers and ultimately the conservation of the valuable germplasm
Some Bianchi Type III String Cosmological Models with Bulk Viscosity
We investigate the integrability of cosmic strings in Bianchi III space-time
in presence of a bulk viscous fluid by applying a new technique. The behaviour
of the model is reduced to the solution of a single second order nonlinear
differential equation. We show that this equation admits an infinite family of
solutions. Some physical consequences from these results are also discussed.Comment: 12 pages, no figure. To appear in Int. J. Theor. Phy
Bianchi type II models in the presence of perfect fluid and anisotropic dark energy
Spatially homogeneous but totally anisotropic and non-flat Bianchi type II
cosmological model has been studied in general relativity in the presence of
two minimally interacting fluids; a perfect fluid as the matter fluid and a
hypothetical anisotropic fluid as the dark energy fluid. The Einstein's field
equations have been solved by applying two kinematical ans\"{a}tze: we have
assumed the variation law for the mean Hubble parameter that yields a constant
value of deceleration parameter, and one of the components of the shear tensor
has been considered proportional to the mean Hubble parameter. We have
particularly dwelled on the accelerating models with non-divergent expansion
anisotropy as the Universe evolves. Yielding anisotropic pressure, the fluid we
consider in the context of dark energy, can produce results that can be
produced in the presence of isotropic fluid in accordance with the \Lambda CDM
cosmology. However, the derived model gives additional opportunities by being
able to allow kinematics that cannot be produced in the presence of fluids that
yield only isotropic pressure. We have obtained well behaving cases where the
anisotropy of the expansion and the anisotropy of the fluid converge to finite
values (include zero) in the late Universe. We have also showed that although
the metric we consider is totally anisotropic, the anisotropy of the dark
energy is constrained to be axially symmetric, as long as the overall energy
momentum tensor possesses zero shear stress.Comment: 15 pages; 5 figures; matches the version published in The European
Physical Journal Plu
Development of High Yielding Fusarium Wilt Resistant Cultivar by Pyramiding of “Genes” Through Marker-Assisted Backcrossing in Chickpea (Cicer arietinum L.)
Pusa 391, a mega desi chickpea variety with medium maturity duration is extensively cultivated in the Central Zone of India. Of late, this variety has become susceptible to Fusarium wilt (FW), which has drastic impact on its yield. Presence of variability in the wilt causing pathogen, Fusarium oxysporum f.sp. ciceri (foc) across geographical locations necessitates the role of pyramiding for FW resistance for different races (foc 1,2,3,4 and 5). Subsequently, the introgression lines developed in Pusa 391 genetic background were subjected to foreground selection using three SSR markers (GA16, TA 27 and TA 96) while 48 SSR markers uniformly distributed on all chromosomes, were used for background selection to observe the recovery of recurrent parent genome (RPG). BC1F1 lines with 75–85% RPG recovery were used to generate BC2F1. The plants that showed more than 90% RPG recovery in BC2F1 were used for generating BC3F1. The plants that showed more than 96% RPG recovery were selected and selfed to generate BC3F3. Multi-location evaluation of advanced introgression lines (BC2F3) in six locations for grain yield (kg/ha), days to fifty percent flowering, days to maturity, 100 seed weight and disease incidence was done. In case of disease incidence, the genotype IL1 (BGM 20211) was highly resistant to FW in Junagarh, Indore, New Delhi, Badnapur and moderately resistant at Sehore and Nandyal. GGE biplot analysis revealed that IL1(BGM20211) was the most stable genotype at Junagadh, Sehore and Nandyal. GGE biplot analysis revealed that IL1(BGM 20211) and IL4(BGM 20212) were the top performers in yield and highly stable across six environments and were nominated for Advanced Varietal Trials (AVT) of AICRP (All India Coordinated Research Project on Chickpea) in 2018–19. BGM20211 and BGM 20212 recorded 29 and 28.5% average yield gain over the recurrent parent Pusa 391, in the AVT-1 and AVT-2 over five environments. Thus, BGM20211 was identified for release and notified as Pusa Manav/Pusa Chickpea 20211 for Madhya Pradesh, Gujarat and Maharashtra, Southern Rajasthan, Bundhelkhand region of Uttar Pradesh states by the Central Sub-Committees on Crop Standards, Notification and Release of Varieties of Agricultural Crops, Ministry of Agriculture and Farmers Welfare, Government of India, for commercial cultivation in India (Gazette notification number S.O.500 (E) dt. 29-1-2021).Such pyramided lines give resilience to multiple races of fusarium wilt with added yield advantage
Assessment of impacts of climate change on rice and wheat in the Indo-Gangetic plains
In this paper, the climate change scenarios of A2 and B2 for 2070-2100 time scale (denoted as 2080) for several key locations of India and its impact on rice and wheat crops based on regional climate model (PRECIS) were described. The PRECIS projects an increase in temperature over most parts of India especially in the IGP (Indo-Gangetic Plains), the region that presently experiences relatively low temperatures. Extreme high temperature episodes and rainfall intensity days are projected to become more frequent and the monsoon rainfall is also projected to increase. Rabi (mid Nov-March) season is likely to experience higher increase in temperature which could impact and hence become threat to the crops which really require low temperature for their growth. Climatic variability is also projected to increase in both A2 and B2 scenarios. All these projected changes are likely to reduce the wheat and rice yields in Indo-Gangetic plains of India. It is likely that there will be more number of years with low yields occurs towards the end of the century. Such yield reductions in rice and wheat crops due to climate change are mediated through reduction in crop duration, grain number and grain filling duration. The yield loss will be more in A2 scenario compared to B2. These quantitative estimates still have uncertainties associated with them, largely due to uncertainties in climate change projections, future technology growth, availability of inputs such as water for irrigation, changes in crop management and genotype. These projections nevertheless provide a direction of likely change in crop productivity in future climate change scenarios
Space-time inhomogeneity, anisotropy and gravitational collapse
We investigate the evolution of non-adiabatic collapse of a shear-free
spherically symmetric stellar configuration with anisotropic stresses
accompanied with radial heat flux. The collapse begins from a curvature
singularity with infinite mass and size on an inhomogeneous space-time
background. The collapse is found to proceed without formation of an even
horizon to singularity when the collapsing configuration radiates all its mass
energy. The impact of inhomogeneity on various parameters of the collapsing
stellar configuration is examined in some specific space-time backgrounds.Comment: To appear in Gen. Relativ. Gra
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