Finite width induced modification to the electromagnetic form factors of spin-1 particles

The inclusion of the unstable features of a spin-1 particle, without breaking the electromagnetic gauge invariance, can be properly accomplished by including higher order contributions as done in the so-called fermion loop scheme (for the W gauge boson), and the boson loop scheme (for vector mesons). This induces a non trivial modification to the electromagnetic vertex of the particle, which must be considered in addition to any other contribution computed as stable particles. Considering the modified electromagnetic vertex, we obtain general expressions for the corresponding corrections to the multipoles as a function of the mass of the particles in the loop. For the W gauge boson no substantial deviations from the stable case is observed. For the rho and K* mesons the mass of the particles in the loop makes a significant effect, and can be comparable with corrections of different nature .Comment: 11 pages, 1 figure. Extended discussion, main equations rewritten to exhibit limiting behavior. Results for K* meson added. Accepted for publication in PR

Giant monopole resonance and nuclear compression modulus for 40Ca and 16O

Using a collective potential derived on the basis of the Generator Coordinate Method with Skyrme interactions we obtain values for the compression modulus of 40Ca which are in good agreement with a recently obtained experimental value. Calculated values for the compression modulus for 16O are also given. The procedure involved in the derivation of the collective potential is briefly reviewed and discussed.Comment: 14 pages, no figures, two tables, REVTE

DATABASE DEVELOPMENT LIFE CYCLE

A software development life cycle model (SDLC) consists of a set of processes (planning, requirements, design, development, testing, installation and maintenance) defined to accomplish the task of developing a software application that is functionally correct and satisfies the user’s needs. These set of processes, when arranged in different orders, characterize different types of life cycles. When developing a database, the order of these tasks is very important to efficiently and correctly transform the user’s requirements into an operational database. These SDLCs are generally defined very broadly and are not specific for a particular type of application. In this paper the authors emphasize that there should be a SDLC that is specific to database applications. Database applications do not have the same characteristics as other software applications and thus a specific database development life cycle (DBDLC) is needed. A DBDLC should accommodate properties like scope restriction, progressive enhancement, incremental planning and pre-defined structure.Software Development, Database, DBMS, lifecycle model, traditional lifecycles

'Workshop for Nagoya Protocol and Plant Treaty National Focal Points in Latin America and the Caribbean’

The capacity-building Workshop for National Focal Points in Latin America and the Caribbean on Mutually Supportive Implementation of the Nagoya Protocol and the International Treaty on Plant Genetic Resources for Food and Agriculture, was held 25-28 September 2018 at the International Potato Center (CIP), Lima, Peru. The workshop was attended by over 60 participants, including National Focal Points for the Nagoya Protocol to the Convention on Biological Diversity and the International Treaty on Plant Genetic Resources (CBD) for Food and Agriculture (Plant Treaty), from 16 countries in Latin America and the Caribbean. The workshop was also attended by representatives from the Secretariats of the Plant Treaty and CBD, the International Seed Federation, farmer and indigenous peoples organizations, national and international agricultural research organizations and experts from the region who have been working for decades on access and benefit-sharing policy issues. The objectives of the workshop were to: 1. Strengthen network ties between National Focal Points within each country and across the regions; 2. Analyse challenges and opportunities for implementing the Plant Treaty and the Nagoya Protocol in a mutually supportive manner, and in ways that advance complementary policy goals, such as climate change adaptation, and improving the livelihoods of indigenous peoples and local communities; 3. Equip participants with tools to help address ‘real life’ scenarios where mutually supportive implementation is important, and 4. Identify the kinds of additional support that countries need to implement the Plant Treaty and Nagoya Protocol in mutually supportive ways

Exploring the Electrical Properties of Twisted Bilayer Graphene

Two-dimensional materials exhibit properties unlike anything else seen in conventional substances. Electrons in these materials are confined to move only in the plane. In order to explore the effects of these materials, we have built apparatus and refined procedures with which to create two-dimensional structures. Two-dimensional devices have been made using exfoliated graphene and placed on gold contacts. Their topography has been observed using Atomic Force Microscopy (AFM) confirming samples with monolayer, bilayer, and twisted bilayer structure. Relative work functions of each have been measured using Kelvin Probe Force Microscopy (KPFM) showing that twisted bilayer graphene has a surface potential 20mV higher than that of monolayer graphene and 35 mV below bilayer graphene

Soliton Stability in Systems of Two Real Scalar Fields

In this paper we consider a class of systems of two coupled real scalar fields in bidimensional spacetime, with the main motivation of studying classical or linear stability of soliton solutions. Firstly, we present the class of systems and comment on the topological profile of soliton solutions one can find from the first-order equations that solve the equations of motion. After doing that, we follow the standard approach to classical stability to introduce the main steps one needs to obtain the spectra of Schr\"odinger operators that appear in this class of systems. We consider a specific system, from which we illustrate the general calculations and present some analytical results. We also consider another system, more general, and we present another investigation, that introduces new results and offers a comparison with the former investigations.Comment: 16 pages, Revtex, 3 f igure