An unified cosmological evolution driven by a mass dimension one fermionic field

An unified cosmological model for an Universe filled with a mass dimension one (MDO) fermionic field plus the standard matter fields is considered. After a primordial quantum fluctuation the field slowly rolls down to the bottom of a symmetry breaking potential, driving the Universe to an inflationary regime that increases the scale factor for about 71 e-folds. After the end of inflation, the field starts to oscillate and can transfer its energy to the standard model particles through a reheating mechanism. Such a process is briefly discussed in terms of the admissible couplings of the MDO field with the electromagnetic and Higgs fields. We show that even if the field loses all its kinetic energy during reheating, it can evolve as dark matter due a gravitational coupling (of spinorial origin) with baryonic matter. Since the field acquires a constant value at the bottom of the potential, a non-null, although tiny, mass term acts as a dark energy component nowadays. Therefore, we conclude that MDO fermionic field is a good candidate to drive the whole evolution of the Universe, in such a way that the inflationary field, dark matter and dark energy are described by different manifestations of a single field.Comment: 22 pages, 5 figure

Graphene-based spin-pumping transistor

We demonstrate with a fully quantum-mechanical approach that graphene can function as gate-controllable transistors for pumped spin currents, i.e., a stream of angular momentum induced by the precession of adjacent magnetizations, which exists in the absence of net charge currents. Furthermore, we propose as a proof of concept how these spin currents can be modulated by an electrostatic gate. Because our proposal involves nano-sized systems that function with very high speeds and in the absence of any applied bias, it is potentially useful for the development of transistors capable of combining large processing speeds, enhanced integration and extremely low power consumption

Graphene as a non-magnetic spin-current lens

In spintronics, the ability to transport magnetic information often depends on the existence of a spin current traveling between two different magnetic objects acting as source and probe. A large fraction of this information never reaches the probe and is lost because the spin current tends to travel omni-directionally. We propose that a curved boundary between a gated and a non-gated region within graphene acts as an ideal lens for spin currents despite being entirely of non-magnetic nature. We show as a proof of concept that such lenses can be utilized to redirect the spin current that travels away from a source onto a focus region where a magnetic probe is located, saving a considerable fraction of the magnetic information that would be otherwise lost.Comment: 9 pages, 3 figure

Dynamic RKKY interaction between magnetic moments in graphene nanoribbons

Graphene has been identified as a promising material with numerous applications, particularly in spintronics. In this paper we investigate the peculiar features of spin excitations of magnetic units deposited on graphene nanoribbons and how they can couple through a dynamical interaction mediated by spin currents. We examine in detail the spin lifetimes and identify a pattern caused by vanishing density of states sites in pristine ribbons with armchair borders. Impurities located on these sites become practically invisible to the interaction, but can be made accessible by a gate voltage or doping. We also demonstrate that the coupling between impurities can be turned on or off using this characteristic, which may be used to control the transfer of information in transistor-like devices.Comment: 10 pages, 10 figure

Corante e óleo aromático de Curcuma longa: aditivos naturais para alimentos.

bitstream/item/65518/1/CTAA-PESQ.-AND.-7-86.pd

Urethral Leak: an Unusual Symptom of Pudendal Nerve Entrapment

Pudendal nerve (PN) entrapment is one of the most misunderstood and underdiagnosed medical conditions. It is recognized as a cause of chronic pelvic pain syndrome. However, due to the pudendal nerve's mixed composition and complex anatomy, the presenting symptoms are varied and go beyond pain, depending on the entrapment's nature, location and duration. We report a unique case of a young patient presenting with a urethral leak refractory to antibiotics. Patient evaluation highlighted findings suspicious of pudendal nerve entrapment. The patient was submitted to a laparoscopic transperitoneal PN neurolysis, resulting in major symptoms improvement.info:eu-repo/semantics/publishedVersio

Carbon nanotube: a low-loss spin-current waveguide

We demonstrate with a quantum-mechanical approach that carbon nanotubes are excellent spin-current waveguides and are able to carry information stored in a precessing magnetic moment for long distances with very little dispersion and with tunable degrees of attenuation. Pulsed magnetic excitations are predicted to travel with the nanotube Fermi velocity and are able to induce similar excitations in remote locations. Such an efficient way of transporting magnetic information suggests that nanotubes are promising candidates for memory devices with fast magnetization switchings