873 research outputs found
Multisensory sensitivity is related to deep-tissue but not cutaneous pain sensitivity in healthy individuals
Phonon-induced decoherence of the two-level quantum subsystem due to relaxation and dephasing processes
Phonon-related decoherence effects in a quantum double-well two-level
subsystem coupled to a solid are studied theoretically by the example of
deformation phonons. Expressions for the reduced density matrix at T=0 are
derived beyond the Markovian approximation by means of explicit solution of the
non-stationary Schrodinger equation for the interacting electron-phonon system
at the initial stage of its evolution. It is shown that as long as the
difference between the energies of the electron in the left and the right well
greatly exceeds the energy of the electron tunneling between the minima of the
double-well potential, decoherence is primarily due to dephasing processes.
This case corresponds to a strongly asymmetric potential and spatially
separated eigenfunctions localized in the vicinity of one or another potential
minimum. In the opposite case of the symmetric potential, the decoherence stems
from the relaxation processes, which may be either "resonant" (at relatively
long times) or "nonresonant" (at short times), giving rise to qualitatively
different temporal evolution of the electron state. The results obtained are
discussed in the context of quantum information processing based on the quantum
bits encoded in electron charge degrees of freedom.Comment: 20 pages, no figure
Facultative Aestivation in a Tropical Freshwater Turtle Chelodina rugosa
Abstract-1. Chelodina rugosa dug from aestivation sites at the end of the dry season were immediately alert and well coordinated. 2. Compared with non-aestivating animals, aestivating turtles had 20% higher plasma osmotic pressure and 7% higher sodium. Coupled with a small, but significant weight gain upon return to the water, this suggested the occurrence of minor dehydration in aestivating animals. 3. Plasma lactate levels of aestivating animals were low, averaging 1.99 mmol/1, consistent with aerobic rather than anaerobic metabolism having sustained their long period under ground. 4. No evidence was seen of dramatic physiological specialization. Aestivation in this species is interpreted as a primarily behavioural adaptation, made possible by typically reptilian abilities to tolerate a wide range in plasma electrolytes and to survive long periods without feeding
Error correction in short time steps during the application of quantum gates
We propose a method for applying the quantum error-correction method for
errors that occur during quantum gates. Using a perturbation treatment of the
noise that allows us to separate it from the ideal evolution of the quantum
gate, we demonstrate that in certain cases it is necessary to divide the
quantum gate in short time steps intercalated by correction procedures. A
prescription of how these gates can be constructed is provided, as well as a
proof that, even for the cases when the division of the quantum gate in short
time steps is not necessary, this method may be advantageous for reducing the
total duration of the computation
Three-body structure of low-lying 18Ne states
We investigate to what extent 18Ne can be descibed as a three-body system
made of an inert 16O-core and two protons. We compare to experimental data and
occasionally to shell model results. We obtain three-body wave functions with
the hyperspherical adiabatic expansion method. We study the spectrum of 18Ne,
the structure of the different states and the predominant transition strengths.
Two 0+, two 2+, and one 4+ bound states are found where they are all known
experimentally. Also one 3+ close to threshold is found and several negative
parity states, 1-, 3-, 0-, 2-, most of them bound with respect to the 16O
excited 3- state. The structures are extracted as partial wave components, as
spatial sizes of matter and charge, and as probability distributions.
Electromagnetic decay rates are calculated for these states. The dominating
decay mode for the bound states is E2 and occasionally also M1.Comment: 17 pages, 5 figures (version to appear in EPJA
Estabilidade do antĂgeno de cĂ©lula total de Brucella abortus para uso no diagnĂłstico sorolĂłgico da brucelose bovina pela reação de fixação de complemento
Entanglement study of the 1D Ising model with Added Dzyaloshinsky-Moriya interaction
We have studied occurrence of quantum phase transition in the one-dimensional
spin-1/2 Ising model with added Dzyaloshinsky-Moriya (DM) interaction from bi-
partite and multi-partite entanglement point of view. Using exact numerical
solutions, we are able to study such systems up to 24 qubits. The minimum of
the entanglement ratio R \tau 2/\tau 1 < 1, as a novel estimator of
QPT, has been used to detect QPT and our calculations have shown that its
minimum took place at the critical point. We have also shown both the
global-entanglement (GE) and multipartite entanglement (ME) are maximal at the
critical point for the Ising chain with added DM interaction. Using matrix
product state approach, we have calculated the tangle and concurrence of the
model and it is able to capture and confirm our numerical experiment result.
Lack of inversion symmetry in the presence of DM interaction stimulated us to
study entanglement of three qubits in symmetric and antisymmetric way which
brings some surprising results.Comment: 18 pages, 9 figures, submitte
Development of a gas chromatography - mass spectrometry method for the determination of carbon disulfide in the atmosphere
[EN] Carbon disulfide (CS2), a relevant reduced sulfur compound in air, is well-known for its malodor and its significant effect on global atmospheric chemistry. Therefore, a reliable method for determining CS2 in atmospheric samples has been developed based on solid-phase sampling and gas chromatography-mass spectrometry (GC-MS). Two types of solid-phase sampling supports (Orbo-32 and SKC) and the elution with organic solvents - hexane and toluene - were evaluated for low-volume outdoor sampling. Recovery studies and the standard addition method were carried out to demonstrate the proper determination of CS2 in the absence of the influence of interferences such as ozone, hydrogen sulfide or water - important atmospheric pollutants. The proposed methodology was validated by performing experiments in a high-volume smog chamber and by comparison with two reference optical methods, Fourier Transform Infrared (FTIR) and Differential Optical Absorption Spectroscopy (DOAS) installed in these facilities. Satisfactory analytical parameters were reported: fast analysis, a correct repeatability of 6±1% and reproducibility of 14±3%, and low detection limits of 0.3-0.9pgm-3. Finally, the method was successfully applied to industrial samples near a pulp factory area, where a high correlation between industrial emissions and reported carbon disulfide concentrations were observed. © 2011 Elsevier B.V.The research leading to these results received funding from the Centro de Investigacion del Medio Ambiente (CIMA), Consejeria de Medio Ambiente, Gobierno de Cantabria. The Instituto Universitario CEAM-UMH is partly supported by Generalitat Valenciana, Fundacion Bancaja, and the projects GRACCIE (Consolider-Ingenio 2010) and FEEDBACKS (Prometeo - Generalitat Valenciana). We also acknowledged the European Community's Seventh Framework Program under the grant agreement no. 228335 (Eurochamp2), the Spanish Ministry of Science and Innovation, through INNPLANTA project: PCT-440000-2010-003 and the EUPHORE staff for their support in the chamber experiments. The authors also thank J.T.B. for his contribution.BorrĂĄs GarcĂa, EM.; RĂłdenas, M.; Dieguez, J.; PĂ©rez-GarcĂa, M.; Lomba, R.; Lavin, J.; Tortajada-Genaro, LA. (2012). Development of a gas chromatography - mass spectrometry method for the determination of carbon disulfide in the atmosphere. Microchemical Journal. 101:37-42. https://doi.org/10.1016/j.microc.2011.10.002S374210
A software to calculate soil hydraulic conductivity in internal drainage experiments (SHC, Version 2.00)
Determination of dichlobenil and its major metabolite (BAM) in onions by PTVâGCâMS using PARAFAC2 and experimental design methodology
The optimization of a GCâMS analytical procedure which includes derivatization, Quick Easy Cheap Effective Rugged and Safe (QuEChERS) and programmed temperature vaporization (PTV) using design of experiments is performed to determine 2,6-dichlorobenzonitrile (dichlobenil) and 2,6-dichlorobenzamide (BAM) in onions, using 3,5-dichlorobenzonitrile and 2,4-dichlorobenzamide as internal standards. The use of a central composite design and two D-optimal designs, together with the desirability function, makes it possible to significantly reduce the economic, time and environmental cost of the study. The usefulness of PARAFAC2 for solving problems as the interference of unexpected derivatization artifacts unavoidably linked to some derivatization agents, or the presence of coeluents from the complex matrix, which share m/z ratios with the target compounds, is shown. The limits of decision (CCα) of the optimized procedure, 5.00 ÎŒg kgâ 1 for dichlobenil and 1.55 ÎŒg kgâ 1 for BAM (α = 0.05), are below the maximum residue limit (MRL) established by the EU for dichlobenil (20 ÎŒg kgâ 1) in this commodity.Ministerio de EconomĂa y Competitividad (CTQ2011-26022) and Junta
de Castilla y LeĂłn (BU108A11-2
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