12,238 research outputs found

    Nuclear incompressibility using the density dependent M3Y effective interaction

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    A density dependent M3Y effective nucleon-nucleon (NN) interaction which was based on the G-matrix elements of the Reid-Elliott NN potential has been used to determine the incompressibity of infinite nuclear matter. The nuclear interaction potential obtained by folding in the density distribution functions of two interacting nuclei with this density dependent M3Y effective interaction had been shown earlier to provide excellent descriptions for medium and high energy α\alpha and heavy ion elastic scatterings as well as α\alpha and heavy cluster radioactivities. The density dependent parameters have been chosen to reproduce the saturation energy per nucleon and the saturation density of spin and isospin symmetric cold infinite nuclear matter. The result of such calculations for nuclear incompressibility using the density dependent M3Y effective interaction based on the G-matrix elements of Reid-Elliott NN potential predicts a value of about 300 MeV for nuclear incompressibility.Comment: 4 Page

    Causality Implies Inflationary Back-Reaction

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    There is a widespread belief among inflationary cosmologists that a local observer cannot sense super-horizon gravitons. The argument goes that a local observer would subsume super-horizon gravitons into a redefinition of his coordinate system. We show that adopting this view for pure gravity on de Sitter background leads to time variation in the Hubble parameter measured by a local observer. It also leads to a violation of the gravitational field equation R=4ΛR = 4 \Lambda because that equation is obeyed by the full metric, rather than the one which has been cleansed of super-horizon modes.Comment: 20 pages, 2 figures, uses LaTeX2e, version 2 slightly revised for publicatio

    Modified Bethe-Weizsacker mass formula with isotonic shift and new driplines

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    Nuclear masses are calculated using the modified Bethe-Weizsacker mass formula in which the isotonic shifts have been incorporated. The results are compared with the improved liquid drop model with isotonic shift. Mass excesses predicted by this method compares well with the microscopic-macroscopic model while being much more simple. The neutron and proton drip lines have been predicted using this modified Bethe-Weizsacker mass formula with isotonic shifts.Comment: 9 pages including 2 figure

    How much do helioseismological inferences depend upon the assumed reference model?

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    We investigate systematic uncertainties in determining the profiles of the solar sound speed, density, and adiabatic index by helioseismological techniques. We find that rms uncertainties-averaged over the sun of ~ 0.2%-0.4% are contributed to the sound speed profile by each of three sources: 1)the choice of assumed reference model, 2) the width of the inversion kernel, and 3) the measurements errors. The density profile is about an order of magnitude less well determined by the helioseismological measurements. The profile of the adiabatic index is determined to an accuracy of about 0.2% . We find that even relatively crude reference models yield reasonably accurate solar parameters.Comment: Accepted for publication in ApJ . Related material at http://www.sns.ias.edu/~jn

    The role of the European Union in the Human Rights Council

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    The European Union has and continues to place human rights and democracy at the heart of its external relations, namely through its activities in the UN human rights system. With the ongoing criticism about the inadequacies of the UN Commission on Human Rights Kofi Annan recommended that this ailing body be replaced with a new and more effective Human Rights Council. In light of the European Union’s desire to further human rights and democracy across the globe it rapidly got involved in playing an active and visible role in the overarching UN human rights reform process. Negotiations for establishing the Human Rights Council in addition to the deliberations of the mandated working groups outlining the details and modalities of the Council involved making difficult and demanding decisions. The different opinions and positions not only led to a delayed inception but also generated concerns that the new Council would not be any more efficient or credible than its predecessor. Many have claimed that its first operational year has produced disappointing results by not taking more concrete action regarding countries facing dire human rights crises such as Zimbabwe. In contrast, others argue that in its first year the Council did achieve a number of successes including the modalities of the Universal Periodic Review process, the review of UN Special Procedures, the adoption of the codes of conduct for mandate holders in addition to the adoption of a number of resolutions of great importance in the Council’s plenary. The European Union actively participated in each phase and in all areas of the Human Rights Council from the setting up process to engaging in the sometimes arduous negotiations of both procedural and substantive matters. While it has indeed been successful in the workings of some areas the EU’s shortcomings have recently overshadowed its achievements. The following study explores the role of the EU in the Human Rights Council from the setting-up process to its contributions in the review of the UN Special Procedures, the UPR process and the plenary sessions since the Council’s inception. Following the highlighting of both the EU’s achievements and shortcomings the study concludes with five core recommendations that have the potential to help rectify the challenges currently faced by the European Union in the Human Rights Council

    On the Performance Calculations of Three Phase Transmission Lines by Relaxation Method

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    Analysis techniques for tracer studies of oxidation

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    Analysis techniques to obtain quantitative diffusion data from tracer concentration profiles were developed. Mass balance ideas were applied to determine the mechanism of oxide growth and to separate the fraction of inward and outward growth of oxide scales. The process of inward oxygen diffusion with exchange was theoretically modelled and the effect of lattice diffusivity, grain boundary diffusivity and grain size on the tracer concentration profile was studied. The development of the tracer concentration profile in a growing oxide scale was simulated. The double oxidation technique was applied to a FeCrAl-Zr alloy using 0-18 as a tracer. SIMS was used to obtain the tracer concentration profile. The formation of lacey oxide on the alloy was discussed. Careful consideration was given to the quality of data required to obtain quantitative information

    Preliminary Studies on the Epidemiology of the Potato Aphids in West Bengal (Homoptera: Aphididae).

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    M. persicae and A. gossypii are the two species of aphids which infest potato crop in West Bengal. Both the species are highly polyphagous and have a wide range of host plants. They infest the potato crop at the early stage of development and persist almost throughout the growing season of the crop. Potato fields nearabout Calcutta are therefore, subjected to the attack of the aphids throughout the growing season. Both the species are abundant before the sowing of potato, in areas near Calcutta. Early sowing of potato in these areas, therefore, is not likely to be effective in avoiding their infestations. The production of the alatae and the peak period of infestation seem to be largely dependant on the condition of the foliage. The aphids are not uniformly distributed on the potato foliage. They are particularly abundant on the middle and lower leaves and as such, insecticidal sprayings should adequately cover the entire foliage for satisfactory control of the aphids.M. persicae and A. gossypii are the two species of aphids which infest potato crop in West Bengal. Both the species are highly polyphagous and have a wide range of host plants. They infest the potato crop at the early stage of development and persist almost throughout the growing season of the crop. Potato fields nearabout Calcutta are therefore, subjected to the attack of the aphids throughout the growing season. Both the species are abundant before the sowing of potato, in areas near Calcutta. Early sowing of potato in these areas, therefore, is not likely to be effective in avoiding their infestations. The production of the alatae and the peak period of infestation seem to be largely dependant on the condition of the foliage. The aphids are not uniformly distributed on the potato foliage. They are particularly abundant on the middle and lower leaves and as such, insecticidal sprayings should adequately cover the entire foliage for satisfactory control of the aphids
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