12,445 research outputs found
Some properties of two Nambu--Jona-Lasinio -type models with inputs from lattice QCD
We investigate the phase diagram of the so-called
Polyakov--Nambu--Jona-Lasinio (PNJL) model at finite temperature and nonzero
chemical potential. The calculations are performed in the light and strange
quark sectors (, , ), which includes the 't Hooft instanton induced
interaction term that breaks the axial symmetry, and the quarks are coupled to
the (spatially constant) temporal background gauge field. On one hand, a
special attention is payed to the critical end point (CEP). The strength of the
flavor-mixing interaction alters the CEP location, since when it becomes weaker
the CEP moves to low temperatures and can even disappear. On the other hand, we
also explore the connection between QCD, a nonlocal Nambu--Jona-Lasinio type
model and the Landau gauge gluon propagator. Possible links between the
quenched gluon propagator and low energy hadronic phenomenology are
investigated.Comment: Contribution to the International Meeting "Excited QCD", Peniche,
Portugal, 06 - 12 May 201
Comportamento de híbridos de coqueiro nos Tabuleiros Costeiros do Piauí.
Com o objetivo de avaliar o comportamento de híbridos de coqueiro nas condições de clima e solo dos Tabuleiros Costeiros do Piauí, conduziu-se um experimento no Campo Experimental da Embrapa Meio-Norte em Parnaíba-PI, no período de 2002 a 2004. Utilizou-se o delineamento experimental de blocos ao acaso, com sete tratamentos e quatro repetições. Os tratamentos foram constituídos por cinco híbridos entre coqueiro-anão e coqueiro-gigante: AAG x GBrPF, AVG x GBrPF, AVeJ x GBrRN, AAG x GOA e AVG x GOA) e os dois parentais (GBrRN e AVeJ) como testemunha. As características vegetativas, avaliadas semestralmente, foram o número de folhas vivas (NFV) emitidas (NFE), e as reprodutivas, avaliadas mensalmente, foram o número de inflorescências emitidas (NIE), número de flores femininas por inflorescência (NFFI) e número de frutos colhidos/planta (NFC). Os híbridos AAG x GBrPF; AVG x GBrP e AVG x GOA apresentam maior potencial de adaptação às condições edafoclimáticas dos Tabuleiros Costeiros do Piauí.bitstream/item/35881/1/BP61.pd
Comportamento de cultivares de coqueiro-anão nos Tabuleiros Costeiros do Piauí.
bitstream/CPAMN-2009-09/20331/1/BOLP60.pd
Phase Coherent Precessional Magnetization Reversal in Micro-scopic Spin Valve Elements
We study the precessional switching of the magnetization in microscopic spin
valve cells induced by ultra short in-plane hard axis magnetic field pulses.
Stable and highly efficient switching is monitored following pulses as short as
140 ps with energies down to 15 pJ. Multiple application of identical pulses
reversibly toggles the cell's magnetization be-tween the two easy directions.
Variations of pulse duration and amplitude reveal alter-nating regimes of
switching and non-switching corresponding to transitions from in-phase to
out-of-phase excitations of the magnetic precession by the field pulse. In the
low field limit damping becomes predominant and a relaxational reversal is
found allowing switching by hard axis fields below the in-plane anisotropy
field threshold.Comment: 17 pages, 4 figure
Atypical Presentations of Hearing Loss in Patients with Acoustic Neuroma
A hipoacúsia neurosensorial unilateral e progressiva é uma das principais manisfestações audiológicas dos doentes com diagnóstico de neurinoma do acústico, estando no entanto descritas outras formas de apresentação. Dos 43 doentes com diagnóstico de neurinoma do acústico, tratados pela equipa de otoneurocirurgia entre 1997 e 2003, identificamos 88,5% com hipoacústica neurosensorial unilateral, 4,6% como hipoacústica neurosensorial súbita, 4,6% com audição simétrica e 2,3% com audição "normal". Estes dados revelam a existência de três formas incomuns de apresentação dos neurinomas, facto que deve levar os otorrinolaringologistas a manterem um elevado grau de alerta perante doentes com queixas que possam sugerir, de algum modo, a presença de neurinoma do acústico
Ocorrência da traça-dos-frutos-do-coqueiro Batrachedra nuciferae L. na Região dos Tabuleiros Costeiros do Estado do Piauí.
bitstream/item/52461/1/CT1590001.pd
Evidence for a spectroscopic direct detection of reflected light from 51 Peg b
The detection of reflected light from an exoplanet is a difficult technical
challenge at optical wavelengths. Even though this signal is expected to
replicate the stellar signal, not only is it several orders of magnitude
fainter, but it is also hidden among the stellar noise. We apply a variant of
the cross-correlation technique to HARPS observations of 51 Peg to detect the
reflected signal from planet 51 Peg b. Our method makes use of the
cross-correlation function of a binary mask with high-resolution spectra to
amplify the minute planetary signal that is present in the spectra by a factor
proportional to the number of spectral lines when performing the cross
correlation. The resulting cross-correlation functions are then normalized by a
stellar template to remove the stellar signal. Carefully selected sections of
the resulting normalized CCFs are stacked to increase the planetary signal
further. The recovered signal allows probing several of the planetary
properties, including its real mass and albedo. We detect evidence for the
reflected signal from planet 51 Peg b at a significance of 3\sigma_noise. The
detection of the signal permits us to infer a real mass of 0.46^+0.06_-0.01
M_Jup (assuming a stellar mass of 1.04\;M_Sun) for the planet and an orbital
inclination of 80^+10_-19 degrees. The analysis of the data also allows us to
infer a tentative value for the (radius-dependent) geometric albedo of the
planet. The results suggest that 51Peg b may be an inflated hot Jupiter with a
high albedo (e.g., an albedo of 0.5 yields a radius of 1.9 \pm 0.3 R_Jup for a
signal amplitude of 6.0\pm0.4 x 10^-5). We confirm that the method we perfected
can be used to retrieve an exoplanet's reflected signal, even with current
observing facilities. The advent of next generation of observing facilities
will yield new opportunities for this type of technique to probe deeper into
exoplanets.Comment: 9 pages, 6 figure
Kidney Graft Dysfunction in a Patient with SARS-CoV-2 Pneumonia – Not Everything is COVID 19
info:eu-repo/semantics/publishedVersio
Dual-probe decoherence microscopy: Probing pockets of coherence in a decohering environment
We study the use of a pair of qubits as a decoherence probe of a non-trivial
environment. This dual-probe configuration is modelled by three
two-level-systems which are coupled in a chain in which the middle system
represents an environmental two-level-system (TLS). This TLS resides within the
environment of the qubits and therefore its coupling to perturbing fluctuations
(i.e. its decoherence) is assumed much stronger than the decoherence acting on
the probe qubits. We study the evolution of such a tripartite system including
the appearance of a decoherence-free state (dark state) and non-Markovian
behaviour. We find that all parameters of this TLS can be obtained from
measurements of one of the probe qubits. Furthermore we show the advantages of
two qubits in probing environments and the new dynamics imposed by a TLS which
couples to two qubits at once.Comment: 29 pages, 10 figure
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