High density planting - an option for higher productivity of Hevea brasiliensis in north eastern region of India

The effect of planting density in rubber (Hevea brasiliensis) was studied in an experiment conducted with three densities viz., 420, 620, 824 trees ha-1. It was observed that lower density had higher percentage of trees ready for tapping during initial years, due to better growth. However, higher density achieved required girth in subsequent years. In spite of decrease in plant number over the years, the highest density had always lower girth even after 24 years of planting. Higher density also has higher percentage of too small trees, not suitable for harvesting latex. The higher plant densities resulted taller plants, increased crotch height and decreased the number of branches and thereby plant density affected yield per tree and yield per unit area. Though the yield per hectare increased with increased plant density during initial years, however declined later period. High yield per tree per tap was observed in the lowest density with lower yield per unit area. Yield increased in all densities with application of stimulant. Percentage of yield increase due to application of stimulant was higher (40%) in medium density (620 trees ha-1) compared to other plant densities. Percentage of wind damage was lower in high density planting during initial years. Total timber volume per hectare was high in higher planting density and lower per tree volume of log compared to lower density. Maintaining a density of 620 trees per hectare appears to be most suitable for north eastern region of India

Glimpses of women’s lives in rural Bihar: impact of male migration

Bihar has a rich history of out-migration from the state, which goes back to as early as the nilieteenth century. However, during the last few decades, migration for work has increased manifold. The sheer scale of out-migration in contemporary Bihar is astounding. At any given point of time, as many as nearly one-half of the total number of working men are absent from the state, as they are working elsewhere in urban and rural centres in the country and abroad. Migration from the state is almost exclusively that of the male population and is embedded in the lives ana life choices of the people. It is not just a livelihood strategy but a way of life in rural Bihar. While there is considera_ble research on various aspects of migration including the nature and pattern of/nigrationfrom Bihar, the profile of migrant workers, migration destinations and other such correlates of a migrant's life outside the village, there is sparse literature on the impact of this migration on people, especially on the women who are left behind in the village. Many research questions remain unanswered. How are institutions such as patriarchy in the village affected by male_migration? How does male migration influence women's well-being and agency? Does migration have an effect on women's mobility? Does it empower or disempower the women who are left behind? What role does technology such as mobile phones play in enabling those left behind to communicate with their migrant family members? What impact does this have on the women left behind in the villages

Coupled channel description of 16O+142,144,146Nd scattering around the Coulomb barrier using a complex microscopic potential

Angular distributions of elastic scattering and inelastic scattering from 2+ 1 state are measured for 16O+142,144,146Nd systems at several energies in the vicinity of the Coulomb barrier. The angular distributions are systematically analyzed in coupled channel framework. Renormalized double folded real optical and coupling potentials with DDM3Y interaction have been used in the calculation. Relevant nuclear densities needed to generate the potentials are derived from shell model wavefunctions. A truncated shell model calculation has been performed and the calculated energy levels are compared with the experimental ones. To simulate the absorption, a 'hybrid' approach is adopted. The contribution to the imaginary potential of couplings to the inelastic channels, other than the 2+ 1 target excitation channel, is calculated in the Feshbach formalism. This calculated imaginary potential along with a short ranged volume Woods-Saxon potential to simulate the absorption in fusion channel reproduces the angular distributions for 16O+146Nd quite well. But for 16O+142,144Nd systems additional surface absorption is found to be necessary to fit the angular distribution data. The variations of this additional absorption term with incident energy and the mass of the target are explored. © 2003 Elsevier Science B.V. All rights reserved

Quark Hadron Phase Transition and Hybrid Stars

We investigate the properties of hybrid stars consisting of quark matter in the core and hadron matter in outer region. The hadronic and quark matter equations of state are calculated by using nonlinear Walecka model and chiral colour dielectric (CCD) model respectively. We find that the phase transition from hadron to quark matter is possible in a narrow range of the parameters of nonlinear Walecka and CCD models. The transition is strong or weak first order depending on the parameters used. The EOS thus obtained, is used to study the properties of hybrid stars. We find that the calculated hybrid star properties are similar to those of pure neutron stars.Comment: 25 pages in LaTex and 9 figures available on request, IP/BBSR/94-3

Graviton Resonances in E+ E- -> MU+ MU- at Linear Colliders with Beamstrahlung and ISR Effects

Electromagnetic radiation emitted by the colliding beams is expected to play an important role at the next generation of high energy e^+ e^- linear collider(s). Focusing on the simplest process e+e- -> mu+ mu-, we show that radiative effects like initial state radiation (ISR) and beamstrahlung can lead to greatly-enhanced signals for resonant graviton modes of the Randall-Sundrum model.Comment: 20 pages Latex, 7 eps figure

Wide-angle α-t coincidence measurement in the breakup of 7Li on 27Al

We have performed wide-angle in-plane coincidence measurements of the alpha particles and tritons emitted in the 48-MeV 7Li projectile breakup reaction on 27Al. The data have been analyzed using the post-form distorted-wave Born-approximation (DWBA) theory of breakup reactions where Coulomb and nuclear breakup as well as their interference terms are included. The theory is able to provide a good description of the experimental data particularly at large relative angles between the fragments. The interference between the Coulomb and nuclear breakup modes is found to be significant

Screening of Dirac flavor structure in the seesaw and neutrino mixing

We consider the mechanism of screening of the Dirac flavor structure in the context of the double seesaw mechanism. As a consequence of screening, the structure of the light neutrino mass matrix, m_\nu, is determined essentially by the structure of the (Majorana) mass matrix, M_S, of new super-heavy (Planck scale) neutral fermions S. We calculate effects of the renormalization group running in order to investigate the stability of the screening mechanism with respect to radiative corrections. We find that screening is stable in the supersymmetric case, whereas in the standard model it is unstable for certain structures of M_S. The screening mechanism allows us to reconcile the (approximate) quark-lepton symmetry and the strong difference of the mixing patterns in the quark and lepton sectors. It opens new possibilities to explain a quasi-degenerate neutrino mass spectrum, special ``neutrino'' symmetries and quark-lepton complementarity. Screening can emerge from certain flavor symmetries or Grand Unification.Comment: 27 pages, 3 figures; references added, discussion of the E6 model modifie