Generation of Closed Timelike Curves with Rotating Superconductors

The spacetime metric around a rotating SuperConductive Ring (SCR) is deduced from the gravitomagnetic London moment in rotating superconductors. It is shown that theoretically it is possible to generate Closed Timelike Curves (CTC) with rotating SCRs. The possibility to use these CTC's to travel in time as initially idealized by G\"{o}del is investigated. It is shown however, that from a technology and experimental point of view these ideas are impossible to implement in the present context.Comment: 9 pages. Submitted to Classical and Quantum Gravit

Deformation of quantum mechanics in fractional-dimensional space

A new kind of deformed calculus (the D-deformed calculus) that takes place in fractional-dimensional spaces is presented. The D-deformed calculus is shown to be an appropriate tool for treating fractional-dimensional systems in a simple way and quite analogous to their corresponding one-dimensional partners. Two simple systems, the free particle and the harmonic oscillator in fractional- dimensional spaces are reconsidered into the framework of the D-deformed quantum mechanics. Confined states in a D-deformed quantum well are studied. D-deformed coherent states are also found.Comment: 12 pages, some misprints have been corrected, two figures are adde

The MARES AUV, a Modular Autonomous Robot for Environment Sampling

In this paper, we discuss the design aspects and the development of the MARES AUV, a 1.5m long vehicle, weighting 32kg, designed and built at the University of Porto, Portugal. This vehicle is highly maneuverable, with the ability to move in the vertical plane, controlling pitch and vertical velocity; forward velocity can also be determined, anywhere between 0 and 2 m/s. MARES can easily integrate any new payload within reason, finding applications in a wide range or areas, such as pollution monitoring, scientific data collection, sonar mapping, underwater video or mine countermeasures

Interação genótipo-ambiente em bovinos: revisão de estudos no Brasil.

bitstream/item/31742/1/Doc-365.pdfVersão eletrônica disponível em papel

Potential of plant products as protectants of stored maize against Sitophilus zeamais Motschulsky (Coleoptera:Curculionidae)

Laboratory studies were carried out to evaluate the effects of some formulations from Mentha pulegium, Lonchocarpus sericeus, Daphne gnidium, Laurus nobilis, Momordica charantia, Nerium oleander and Ptaeroxylon obliquum as protectants against adult insects of Sitophilus zeamais on stored maize. The dusts from leaves of L. nobilis at 30% w/w caused 86% mortality and reduced F1 progeny emergence up to 57%. At the same concentration, dusts of pink flowers from N. oleander and leaves from L. sericeus reduced the F1 progeny up to 68% and 70%, reduced the developmental index and prolonged the developmental period by 4 and 6 d, respectively. The suspensions (2% v/v) from M. charantia, N. oleander and P. obliquum reduced the F1 progeny emergence up to 58, 91 and 94% and the number of holes in grains by 75, 91 and 97%, respectively. The methanol extracts were more effective than n-hexane extracts and affected the F1 progeny emergence and the developmental index. Keywords: Sitophilus zeamais, Botanical insecticides, Repellence, Insect control agents

Implementing and solving games with best payoff method

It is our intention, in this chapter, to propose and discuss the Best Payoff Method, a new method to resolve games. This is made exemplifying the application of the method to a pay raise voting game, that is a perfect information sequential game, without having yet formulated it, and then deploying the algorithm for its implementation. In the next examples we consider an imperfect information game and a game with random characteristics. We finish confronting the equilibrium concepts mentioned in this work: Subgame Perfect Nash Equilibrium, Nash Equilibrium, and Best Payoff Equilibrium through the formulation of some conjectures, and with a short conclusions section.info:eu-repo/semantics/acceptedVersio

Synthesis of shaped-beam radiation patterns at millimeter-waves using transmit arrays

Transmit arrays have been mostly used for beam collimation applications, either with fixed or scanning beam capability. But transmit arrays can also be used to synthesize power radiation patterns complying with power pattern templates. A new analytical formulation is presented here to obtain a phase-only correction function corresponding to a given power template. The transmit-array transforms the known power radiation pattern of the primary source into a desired output power pattern. The proposed formulation, specialized for axial-symmetric structures, is based on geometrical optics and provides the solution directly from the evaluation of two closed-form first-order differential equations. As a proof of concept, a sec 2 with a roll-off at 45° is defined as the target power pattern, at the 30 GHz Ka-band. A 10.8 dBi radiation pattern with the circular polarization is used to illuminate a 180 mm ×180 mm transmit array with 60 mm focal distance. Previously designed 3.35 mm thick phase-delay unit cells are used as an example to implement the calculated phase distribution over the transmit-array aperture. The measured antenna radiation pattern matches quite well the template, with a steep fall of the radiation at the roll-off angle and low cross-polarization. This validates the concept, the formulation, and the fabricated prototype.info:eu-repo/semantics/acceptedVersio