Detection of Spiral photons in Quantum Optics

We show that a new type of photon detector, sensitive to the gradients of electromagnetic fields, should be a useful tool to characterize the quantum properties of spatially-dependent optical fields. As a simple detector of such a kind, we propose using magnetic dipole or electric quadrupole transitions in atoms or molecules and apply it to the detection of spiral photons in Laguerre-Gauss (LG) beams. We show that LG beams are not true hollow beams, due to the presence of magnetic fields and gradients of electric fields on beam axis. This approach paves the way to an analysis at the quantum level of the spatial structure and angular momentum properties of singular light beams.Comment: 5 pages, 4 figure

Numerical solution of linear models in economics: The SP-DG model revisited

In general, complex and large dimensional models are needed to solve real economic problems. Due to these characteristics, there is either no analytical solution for them or they are not attainable. As a result, solutions can be only obtained through numerical methods. Thus, the growing importance of computers in Economics is not surprising. This paper focuses on an implementation of the SP-DG model, using Matlab,developed by the students as part of the Computational Economics course. We also discuss some of our teaching/learning experience within the course, given for the first time in the FEP Doctoral Programme in Economics.SP-DG Model, Output, Inflation, Numerical Simulation, Teaching of Economics

Doenças do girassol.

Mancha de Alternaria - Alternaria spp.; Podridao branca - Sclerotinia sclerotiorum (Lib.) de Bary; Mildio - Plasmopara halstedii (Farl.) Berl. & de Toni; Ferrugem - Puccinia helianthi Schw.; Bolha branca - Albugo tragopogi (Pers.) Schroet; Oidio - Erysiphe cichoracearum DC; Mancha cinzenta da haste - Phomopsis helianthi Munth. - Cvet. et al.; Mancha preta da haste - Phoma oleracea var. helianthi tuberosi Sacc.; Outras podridoes radiculares e murchas - Sclerotium rolfsii Sacc., Macrophomina phaseolina (Tass.) Goid e Verticillium dahliae Klebahn; Podridao cinza do capitulo - Botrytis cinerea Pers. ex Fr.; Mancha bacteriana e crestamento bacteriano - Pseudomonas syringae pv. helianthi (Kawamura) Dye, Wilkie et Young; Pseudomonas cichorii (Swingle) Stapp; Podridao da medula da haste - Erwinia sp.; Mosaico comum do girassol - virus do mosaico do picao ("sunflower mosaic virus"); Controle de doencas.bitstream/item/40506/1/Doencas-do-girassol.pd