1,939 research outputs found
Exact results for the star lattice chiral spin liquid
We examine the star lattice Kitaev model whose ground state is a a chiral
spin liquid. We fermionize the model such that the fermionic vacua are toric
code states on an effective Kagome lattice. This implies that the Abelian phase
of the system is inherited from the fermionic vacua and that time reversal
symmetry is spontaneously broken at the level of the vacuum. In terms of these
fermions we derive the Bloch-matrix Hamiltonians for the vortex free sector and
its time reversed counterpart and illuminate the relationships between the
sectors. The phase diagram for the model is shown to be a sphere in the space
of coupling parameters around the triangles of the lattices. The abelian phase
lies inside the sphere and the critical boundary between topologically distinct
Abelian and non-Abelian phases lies on the surface. Outside the sphere the
system is generically gapped except in the planes where the coupling parameters
are zero. These cases correspond to bipartite lattice structures and the
dispersion relations are similar to that of the original Kitaev honeycomb
model. In a further analysis we demonstrate the three-fold non-Abelian
groundstate degeneracy on a torus by explicit calculation.Comment: 7 pages, 8 figure
Are high strivers for justice more unjust when they react to a victim? Further evidence on the effects of the belief in a just world, of the innocence of the victim and of the persistence of suffering on secondary victimization
This research aims to further explore the effects of Belief in a Just World (BJW), victim’s innocence and persistence of suffering on secondary victimization. Previous studies showed that an innocent victim whose suffering is more persistent is more secondarily victimized by high BJW participants than by low BJW participants (Correia & Vala, 2003). This study intends to replicate this finding and to overcome methodological limitations of these previous studies. Participants were 266 undergraduate students. The design was between-subjects 2 BJW (high, low) X 2 innocence of the victim (innocent, non-innocent) X 2 persistence of the suffering of the victim (more persistent, less persistent). The results supported partially the predictions. Theoretical as well as social implications of these findings are discussed
Optical measurements of electrophoretic suspension kinetics
Electrophoretic deposition (EPD) was originally used for formation of coatings, e. g. in the automotive industry.
Recently EPD is successfully utili
zed for thin film preparation with an app
lication in the optics and electronics. This
paper investigates the process of the suspension formation and aggregation by ultraviolet and visible spectroscopy (UV-
VIS) spectroscopy and Dynamic Light Scattering (DLS) methods. The suspensions were formed by a precipitation of
solution of poly[2-methoxy-5-(3
′
,7
′
-dimethyloctyloxy)-1,4-phenylenevinylene]
in toluene using acetonitrile as a
precipitator. It could be concluded that the progressive suspension particle growth observed by DLS affects regularly
the first derivative of the UV-VIS spectra. By a comparison of the results obtained by both methods it could be seen that
UV-VIS spectroscopy combined with the
spline method could be successfully used
for an estimation of electrophoretic
suspensions
Globally Optimal Quantum Control
Optimization methods for constrained quantum control problems power quantum
technologies. Such control problems are notoriously difficult because they are
non-convex and plagued with local extrema. Current optimization methods must be
repeated many times to find good solutions, each time requiring many
simulations of the system. Here we present Quantum Control via Polynomial
Optimization (QCPOp), a method that eliminates this problem by directly finding
globally optimal solutions. This remarkable ability is due to global
optimization methods recently developed for polynomial functions. We
demonstrate the tremendous improvement over current state-of-the-art methods
using a number of non-trivial examples. Global optimization also allows QCPOp
to find the simplest control solutions. Since QCPOp is able to reveal the
optimum performance of quantum control with high confidence, we expect that it
will not only enhance the utility of such control but provide a key tool for
determining the limits of quantum technologies.Comment: Significantly updated content with many new cool examples (10 pages
and 6 figures
Relative vibrotactile spatial acuity of the torso
While tactile acuity for pressure has been extensively investigated, far less is known about acuity for vibrotactile stimulation. Vibrotactile acuity is important however, as such stimulation is used in many applications, including sensory substitution devices. We tested discrimination of vibrotactile stimulation from eccentric rotating mass motors with in-plane vibration. In 3 experiments, we tested gradually decreasing center-to-center (c/c) distances from 30 mm (experiment 1) to 13 mm (experiment 3). Observers judged whether a second vibrating stimulator (‘tactor’) was to the left or right or in the same place as a first one that came on 250 ms before the onset of the second (with a 50-ms inter-stimulus interval). The results show that while accuracy tends to decrease the closer the tactors are, discrimination accuracy is still well above chance for the smallest distance, which places the threshold for vibrotactile stimulation well below 13 mm, which is lower than recent estimates. The results cast new light on vibrotactile sensitivity and can furthermore be of use in the design of devices that convey information through vibrotactile stimulation.Peer Reviewe
Histopathological features of organs in a rat model of mamamry carcinogenesis: a reference database
Mammary tumors’ development was induced through the intraperioneal administration of the carcinogen N-methyl-N-nitrosourea (MNU). Animals from group control were injected with the vehicle (saline solution). Animals were sacrificed at 25 weeks-old and the organs were histopathologically evaluated. A higher number of lesions was observed in the organs of animals from group MNU. The animals from group control did not present any lesion in lymph nodes. Independently of the experimental group, the internal organs presented hemodynamic alterations, degenerative and inflammatory changes. Hemodynamic changes may be consequence of euthanasia method. As expected, the higher number and the higher grade of the lesions in group MNU were due to the carcinogen administration.info:eu-repo/semantics/publishedVersio
How fair is economic inequality? Belief in a just world and the legitimation of economic disparities in 27 European countries
This article aims to examine the role of Belief in a Just World (BJW) in the legitimation of economic inequality. Using data from 27 European countries (N=47,086), we conducted multilevel analyses and found that BJW positively predicted the legitimation of economic inequality, measured by three indicators: the perceived fairness of the overall wealth inequality, and the fairness of the earnings made by the Top 10% and the Bottom 10% of society. These results persisted after controlling for individual- and country-level variables. Moreover, the BJW effect was stronger on the legitimation of the Bottom 10% incomes, compared to the legitimation of the Top 10%. We also found that economic inequality at the country-level reduced the BJW effect on legitimation of inequality. Finally, BJW displayed a negative indirect effect on support for redistribution, via the legitimation of economic inequalities.info:eu-repo/semantics/acceptedVersio
SalivaPrint: sheep saliva electrophoretic protein profile in a bioinformatics approach
info:eu-repo/semantics/acceptedVersio
A scalable quantum computer with an ultranarrow optical transition of ultracold neutral atoms in an optical lattice
We propose a new quantum-computing scheme using ultracold neutral ytterbium
atoms in an optical lattice. The nuclear Zeeman sublevels define a qubit. This
choice avoids the natural phase evolution due to the magnetic dipole
interaction between qubits. The Zeeman sublevels with large magnetic moments in
the long-lived metastable state are also exploited to address individual atoms
and to construct a controlled-multiqubit gate. Estimated parameters required
for this scheme show that this proposal is scalable and experimentally
feasible.Comment: 6 pages, 6 figure
Evaluation of renal injury caused by acute volume replacement with hydroxyethyl starch 130/0.4 or Ringer's lactate solution in pigs
This work aimed to evaluate the effects on renal tissue integrity after hydroxyethyl starch (HES) 130/0.4 and Ringer’s lactate (RL) administration in pigs under general anesthesia after acute bleeding. A total of 30 mL/kg of blood were passively removed from the femoral artery in two groups of Large White pigs, under total intravenous anesthesia with propofol and remifentanil. After bleeding, Group 1 (n =11) received RL solution (25 mL/kg) and Group 2 (n = 11) received HES 130/0.4 solution (20 mL/kg). Additionally, Group 3 (n = 6) was not submitted to bleeding or volume replacement. Pigs were euthanized and kidneys were processed for histopathological and
immunohistochemical analyses. Minimal to moderate glomerular, tubular, and interstitial changes, as well as papillary necrosis, were observed in all experimental groups. Pre-apoptosis and apoptosis indicators were higher in pigs that received HES 130/0.4, indicating a higher renal insult. Both HES 130/0.4 and RL administration may cause renal injury, although renal injury may be more significant in pigs receiving HES 13/0.4. Results also suggest that total intravenous anesthesia with propofol and remifentanil may cause renal injury, and this effect can be dose related.info:eu-repo/semantics/publishedVersio
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