1,253 research outputs found
Curvature Inspired Cosmological Scenario
Using modified gravity with non-linear terms of curvature, and (with being the positive real number and being the scalar
curvature), cosmological scenario,beginning at the Planck scale, is obtained.
Here, a unified picture of cosmology is obtained from gravity. In this
scenario, universe begins with power-law inflation, followed by deceleration
and acceleration in the late universe as well as possible collapse of the
universe in future. It is different from dark energy models with
non-linear curvature terms assumed as dark energy. Here, dark energy terms are
induced by linear as well as non-linear terms of curvature in Friedmann
equation being derived from modified gravity.It is also interesting to see
that, in this model, dark radiation and dark matter terms emerge spontaneously
from the gravitational sector. It is found that dark energy, obtained here,
behaves as quintessence in the early universe and phantom in the late universe.
Moreover, analogous to brane-tension in brane-gravity inspired Friedmann
equation, a tension term arises here being called as cosmic tension.
It is found that, in the late universe, Friedmann equation (obtained here)
contains a term ( being the phantom energy density)
analogous to a similar term in Friedmann equation with loop quantum effects, if
and brane-gravity correction when Comment: 19 Pages. To appear in Int. J. Thro. Phy
Extent of Groundwater Extraction and Irrigation Efficiency on Farms under Different Water-market Regimes in Central Uttar Pradesh
Tube-well irrigation, through modern water extraction mechanisms (WEMs), has been vital to food security and sustainable livelihoods in India. However, due to skewed distribution of WEMs towards large farmers on account of huge investment needs, small and marginal farmers have to rely on owners of WEMs for irrigation water. This has resulted in the emergence of informal water-markets. The present study has examined the groundwater extraction and water-use efficiency under different water-market regimes in the Central Plain Zone (CPZ) of Uttar Pradesh, where water-intensive cropping pattern is followed. The study is based on the primary data collected from 100 farmer-households of Central Plain Zone in the year 2007. Most of the farmers in the study domain are small and marginal, having less than 2 ha land. These resource-poor farmers buy water from the WEMâowners. Thus, groundwater market has been found to provide them easy accessibility to irrigation water and helps them in realizing better yields. The popularity of water-intensive crops, such as paddy, wheat and sugarcane, is responsible for the depleting groundwater tables in the region. Estimates of Data Envelopment Analysis (DEA) have shown that both buyers and owners of WEMs are technically inefficient in waterâuse, as the actual use of irrigation water has been found much higher than the optimum level. However, âBuyers have been found comparatively more efficient than âOwnersâ in water utilization. Overexploitation of groundwater resources raises concerns about the future sustainability of agriculture. It is, therefore, becoming increasingly important that groundwater is used efficiently and groundwater market can emerge as a better tool for improving the efficiency of irrigation water across farm-sizes and crops. Based on the results, the study has made some policy suggestions also for an equitable and sustainable development of agriculture in the region.Agricultural and Food Policy,
Photo thermal induced effects on testes and pituitary gonadotropic cells during resting phase of reproductive cycle in a murrel, Channa punctatus (Bloch)
Effects of various combinations of photoperiod and temperature (NL-NT, LD 15:9-28°C, NL-28°C and LD 15:9 NT) were studied on testicular activity and pituitary gonadotropic cells in Channa punctatus during resting phase of reproductive cycle. Long photoperiod (LD 15:9-28°C) and warm temperature (NL-28°C) regimes were found to be more effective for testicular maturation and secretory activity of gonadotropic cells suggesting testicular maturation via brain-pituitary-testicular axis
Higher order duality in multiobjective fractional programming with support functions
AbstractIn this paper a new class of higher order (F,Ï,Ï)-type I functions for a multiobjective programming problem is introduced, which subsumes several known studied classes. Higher order MondâWeir and Schaible type dual programs are formulated for a nondifferentiable multiobjective fractional programming problem where the objective functions and the constraints contain support functions of compact convex sets in Rn. Weak and strong duality results are studied in both the cases assuming the involved functions to be higher order (F,Ï,Ï)-type I. A number of previously studied problems appear as special cases
Morphological characterization of forage sorghum genotypes for its various DUS traits
The present investigation was conducted to characterize 20 genotypes of sorghum {Sorghum bicolor (L.) moench} on the basis of 33 morphological characters provided by Protection of Plant Variety & Farmerâs Right Act (PPV&FRA) for Distinctiveness Uniformity and Stability (DUS) testing in sorghum. Experimental results revealed that maximum variation was found on the basis of glume colour among the genotypes i.e. G 46, HC 308, HJ 513 had green white, IS 3237, SSG 9, HC 171 had yellow white, SSG 59-3, COFS 29 had grayed purple, S 437-1, SGL-87, S 540-S, SSG (PSSG) had grayed yellow and remaining seven genotypes had grayed orange glume colour. The studied traits showed five genotypes had distinct state of expression. Genotype S-540 showed very high plant height upto the base of flag leaf, HC 136 had compact panicle density at maturity, COFS 29 had very long glume length, SSG 59-3 had distinct expression for days to panicle emergence (50 % of the plants with 50 % of anthesis) and COFS 29 and IS 18551 had short and very long leaf width of blade, respectively. The Principal Component Analysis (PCA) revealed principal Factor (PFI) and Principal Factor (PFII) with maximum variability (64.99 %). Classification of genotypes on the basis of DUS traits provided identification of key characteristics of various genotypes
Scale Factor Dependent Equations of State for Curvature Inspired Dark Energy, Phantom Barrier and Late Cosmic Acceleration
Here, it is found that dark energy and dark matter emerge from the
gravitational sector, if non-linear term of scalar curvature is added to
Einstein-Hilbert lagrangian. An equation of state for dark energy, having the
form p_{\rm de}(\rho_{\rm de})f(a)a(t)t{\rm w}_{\rm de} = p_{\rm
de}/\rho_{\rm de} = - 1a = a_{\rm w}a < a_{\rm
w}, {\rm w}_{\rm de} > - 1{\rm w}_{\rm de} a_{\rm w},a = a_{\rm w} < a_0
(a_0$ being current scale factor of the universe). PACS no.: 98.80 Cq.Comment: 10 PAGES. To appear in Phys. Lett.
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