300 research outputs found

    Risk of Financing Agriculture in the North-Eastern Hill Region of India with Special Reference to Meghalaya

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    The study pertains to the economic issues of risk and uncertainties associated with financing hill agriculture from the twin angles of risk of farmers to utilize the credit and of bankers to disburse the agricultural loan. The issues discussed are: first, why the financial institutions are reluctant to lend agricultural advances? Second, whether the farm income or rate of return on equity and non-equity capital is sufficient to repay the loan? Third, what are the major sources and the magnitude of risks and uncertainties associated with hill farming? Fourth, nature of agricultural marketing situation and how it affects the farm income in this region and finally, the possibilities have been explored, where and how the agricultural lending can be stepped up with positive economic return? The study has revealed that agricultural farming in north-east region of India is severely constrained by high risk and uncertainty arising out from various factors. Under the prevailing condition the expectation of a steady and assured income from agriculture is quite limited; hence, the hill farming fails to attract considerable private investment. The prevailing risk and uncertainty situation compels them to operate at low-input and low-output subsistence farming with low volume of marketable surplus. It has been found that the financial institutions face difficulty in financing the hill agriculture in view of low repayment performance and increasing non-performing assets for agricultural loan. Also, the absence/poor performance of crop insurance scheme (presently only Meghalaya and Sikkim are implementing the National Agricultural Insurance Scheme) increases the risk of hill farming considerably. Non-availability of reliable agricultural database (time series as well as cross section) on area, production and yield, cost of cultivation has been found the major impediments for implementing the crop insurance scheme efficiently. The agricultural situation in this region is highly heterogeneous; variability is extremely high even within a few kilometres of area. It has been suggested that suitable methodologies followed by a wide database be developed to estimate the yield and cost of production of horticultural crops which will help policymakers to formulate right policy to protect the interest of farmers as well as smooth functioning of all stakeholders — entrepreneurs, private investors, bankers and crop insurance implementing agencies.Agricultural and Food Policy,

    Impact of torrential rain on coastal ecosystem at kalpakkam, southeast coast of India

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    1609-1615The present study focuses on the drastic changes observed in the coastal ecosystem at Kalpakkam during flooding event due to huge rainfall that occurred in and around northern Tamil Nadu during December 2015. A significant increase in hydrological parameters (nitrate, phosphate, silicate, total nitrogen and phosphorous) was recorded as compared to previous years (2006-2014). In the present instance, the coastal water salinity which was about 19 psu was the lowest as compared to the data available since 1979. The phytoplankton population density was severely affected by the runoff. The present observed density 1.4 x 104 cells l-1 was the lowest among the available data at this coast. Availability of green algae species in the coastal waters was significantly high (10 species, 17 % of total species) as compared to previous reports. One of the most interesting features of this study was the observation of epibiosis on zooplankton in massive numbers. A comparison of previous occurrences of epibiotic relationship in plankton community with the present observation showed a staggering increase in epibiosis to 38 % of zooplankton species as compared to 5-13 % during 2008-2014

    Effect of Nyquist Noise on the Nyquist Dephasing Rate in 2d Electron Systems

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    We measure the effect of externally applied broadband Nyquist noise on the intrinsic Nyquist dephasing rate of electrons in a two-dimensional electron gas at low temperatures. Within the measurement error, the phase coherence time is unaffected by the externally applied Nyquist noise, including applied noise temperatures of up to 300 K. The amplitude of the applied Nyquist noise from 100 MHz to 10 GHz is quantitatively determined in the same experiment using a microwave network analyzer.Comment: 5 pages, 4 figures. Author affiliation clarified; acknowledgements modified. Replacement reason clarifie

    ANN-based energy reconstruction procedure for TACTIC gamma-ray telescope and its comparison with other conventional methods

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    The energy estimation procedures employed by different groups, for determining the energy of the primary γ\gamma-ray using a single atmospheric Cherenkov imaging telescope, include methods like polynomial fitting in SIZE and DISTANCE, general least square fitting and look-up table based interpolation. A novel energy reconstruction procedure, based on the utilization of Artificial Neural Network (ANN), has been developed for the TACTIC atmospheric Cherenkov imaging telescope. The procedure uses a 3:30:1 ANN configuration with resilient backpropagation algorithm to estimate the energy of a γ\gamma-ray like event on the basis of its image SIZE, DISTANCE and zenith angle. The new ANN-based energy reconstruction method, apart from yielding an energy resolution of \sim 26%, which is comparable to that of other single imaging telescopes, has the added advantage that it considers zenith angle dependence as well. Details of the ANN-based energy estimation procedure along with its comparative performance with other conventional energy reconstruction methods are presented in the paper and the results indicate that amongst all the methods considered in this work, ANN method yields the best results. The performance of the ANN-based energy reconstruction has also been validated by determining the energy spectrum of the Crab Nebula in the energy range 1-16 TeV, as measured by the TACTIC telescope.Comment: 23pages, 9 figures Accepted for publication in NIM

    Observations of TeV gamma-rays from Mrk 421 during Dec. 2005 to Apr. 2006 with the TACTIC telescope

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    The TACTIC γ\gamma-ray telescope has observed Mrk 421 on 66 clear nights from Dec. 07, 2005 to Apr. 30, 2006, totalling \sim 202 hours of on-source observations. Here, we report the detection of flaring activity from the source at \geq 1 TeV energy and the time-averaged differential γ\gamma-ray spectrum in the energy range 1-11 TeV for the data taken between Dec. 27, 2005 to Feb. 07, 2006 when the source was in a relatively higher state as compared to the rest of the observation period. Analysis of this data spell, comprising about \sim97h reveals the presence of a 12.0σ\sim 12.0 \sigma γ\gamma-ray signal with daily flux of >> 1 Crab unit on several days. A pure power law spectrum with exponent 3.11±0.11-3.11\pm0.11 as well as a power law spectrum with an exponential cutoff (Γ=2.51±0.26(\Gamma = -2.51\pm0.26 and E0=(4.7±2.1)TeV)E_0=(4.7\pm2.1) TeV) are found to provide reasonable fits to the inferred differential spectrum within statistical uncertainties. We believe that the TeV light curve presented here, for nearly 5 months of extensive coverage, as well as the spectral information at γ\gamma-ray energies of >> 5 TeV provide a useful input for other groups working in the field of γ\gamma-ray astronomy.Comment: 13pages,4figures; Accepted for publication in Astroparticle Physic

    Anisotropic flow of charged hadrons, pions and (anti-)protons measured at high transverse momentum in Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm NN}}=2.76 TeV

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    The elliptic, v2v_2, triangular, v3v_3, and quadrangular, v4v_4, azimuthal anisotropic flow coefficients are measured for unidentified charged particles, pions and (anti-)protons in Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm NN}} = 2.76 TeV with the ALICE detector at the Large Hadron Collider. Results obtained with the event plane and four-particle cumulant methods are reported for the pseudo-rapidity range η<0.8|\eta|<0.8 at different collision centralities and as a function of transverse momentum, pTp_{\rm T}, out to pT=20p_{\rm T}=20 GeV/cc. The observed non-zero elliptic and triangular flow depends only weakly on transverse momentum for pT>8p_{\rm T}>8 GeV/cc. The small pTp_{\rm T} dependence of the difference between elliptic flow results obtained from the event plane and four-particle cumulant methods suggests a common origin of flow fluctuations up to pT=8p_{\rm T}=8 GeV/cc. The magnitude of the (anti-)proton elliptic and triangular flow is larger than that of pions out to at least pT=8p_{\rm T}=8 GeV/cc indicating that the particle type dependence persists out to high pTp_{\rm T}.Comment: 16 pages, 5 captioned figures, authors from page 11, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/186

    Centrality dependence of charged particle production at large transverse momentum in Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm{NN}}} = 2.76 TeV

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    The inclusive transverse momentum (pTp_{\rm T}) distributions of primary charged particles are measured in the pseudo-rapidity range η<0.8|\eta|<0.8 as a function of event centrality in Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm{NN}}}=2.76 TeV with ALICE at the LHC. The data are presented in the pTp_{\rm T} range 0.15<pT<500.15<p_{\rm T}<50 GeV/cc for nine centrality intervals from 70-80% to 0-5%. The Pb-Pb spectra are presented in terms of the nuclear modification factor RAAR_{\rm{AA}} using a pp reference spectrum measured at the same collision energy. We observe that the suppression of high-pTp_{\rm T} particles strongly depends on event centrality. In central collisions (0-5%) the yield is most suppressed with RAA0.13R_{\rm{AA}}\approx0.13 at pT=6p_{\rm T}=6-7 GeV/cc. Above pT=7p_{\rm T}=7 GeV/cc, there is a significant rise in the nuclear modification factor, which reaches RAA0.4R_{\rm{AA}} \approx0.4 for pT>30p_{\rm T}>30 GeV/cc. In peripheral collisions (70-80%), the suppression is weaker with RAA0.7R_{\rm{AA}} \approx 0.7 almost independently of pTp_{\rm T}. The measured nuclear modification factors are compared to other measurements and model calculations.Comment: 17 pages, 4 captioned figures, 2 tables, authors from page 12, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/284

    Particle-yield modification in jet-like azimuthal di-hadron correlations in Pb-Pb collisions at sNN\sqrt{s_{\rm NN}} = 2.76 TeV

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    The yield of charged particles associated with high-pTp_{\rm T} trigger particles (8<pT<158 < p_{\rm T} < 15 GeV/cc) is measured with the ALICE detector in Pb-Pb collisions at sNN\sqrt{s_{\rm NN}} = 2.76 TeV relative to proton-proton collisions at the same energy. The conditional per-trigger yields are extracted from the narrow jet-like correlation peaks in azimuthal di-hadron correlations. In the 5% most central collisions, we observe that the yield of associated charged particles with transverse momenta pT>3p_{\rm T}> 3 GeV/cc on the away-side drops to about 60% of that observed in pp collisions, while on the near-side a moderate enhancement of 20-30% is found.Comment: 15 pages, 2 captioned figures, 1 table, authors from page 10, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/350

    Measurement of charm production at central rapidity in proton-proton collisions at s=2.76\sqrt{s} = 2.76 TeV

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    The pTp_{\rm T}-differential production cross sections of the prompt (B feed-down subtracted) charmed mesons D0^0, D+^+, and D+^{*+} in the rapidity range y<0.5|y|<0.5, and for transverse momentum 1<pT<121< p_{\rm T} <12 GeV/cc, were measured in proton-proton collisions at s=2.76\sqrt{s} = 2.76 TeV with the ALICE detector at the Large Hadron Collider. The analysis exploited the hadronic decays D0^0 \rightarrow Kπ\pi, D+^+ \rightarrow Kππ\pi\pi, D+^{*+} \rightarrow D0π^0\pi, and their charge conjugates, and was performed on a Lint=1.1L_{\rm int} = 1.1 nb1^{-1} event sample collected in 2011 with a minimum-bias trigger. The total charm production cross section at s=2.76\sqrt{s} = 2.76 TeV and at 7 TeV was evaluated by extrapolating to the full phase space the pTp_{\rm T}-differential production cross sections at s=2.76\sqrt{s} = 2.76 TeV and our previous measurements at s=7\sqrt{s} = 7 TeV. The results were compared to existing measurements and to perturbative-QCD calculations. The fraction of cdbar D mesons produced in a vector state was also determined.Comment: 20 pages, 5 captioned figures, 4 tables, authors from page 15, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/307
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