1,771 research outputs found
Strain sensing based on radiative emission-absorption mechanism using dye-doped polymer optical fiber
A stress sensor based on a dye-doped polymeric optical fiber is able to detect stress by simple comparison of two luminescence peaks from a pair of energy transfer organic dyes. Coumarin 540A (donor) and Rhodamine 6G (acceptor) were doped in the core and cladding of the fiber, respectively. For various laser wavelengths, the change in the near-field pattern and visible emission spectrum upon variation in the fiber bending diameter was evaluated. From a comparison with a low-numerical-aperture fiber, it is shown that the sensitivity of the sensor is controllable by optimization of the waveguide parameters
Continuum-discretized coupled-channels method for four-body nuclear breakup in He+C scattering
We propose a fully quantum-mechanical method of treating four-body nuclear
breakup processes in scattering of a projectile consisting of three
constituents, by extending the continuum-discretized coupled-channels method.
The three-body continuum states of the projectile are discretized by
diagonalizing the internal
Hamiltonian of the projectile with the Gaussian basis functions. For
He+C scattering at 18 and 229.8 MeV, the validity of the method is
tested by convergence of the elastic and breakup cross sections with respect to
increasing the number of the basis functions. Effects of the four-body breakup
and the Borromean structure of He on the elastic and total reaction cross
sections are discussed.Comment: 5 pages, 6 figures, uses REVTeX 4, submitted to Phys. Rev.
Determination of S17 from 8B breakup by means of the method of continuum-discretized coupled-channels
The astrophysical factor for 7Be(p,\gamma)8B at zero energy, S17(0), is
determined from an analysis of 208Pb(8B, p+7Be)208Pb at 52 MeV/nucleon by means
of the method of continuum-discretized coupled-channels (CDCC) taking account
of all nuclear and Coulomb breakup processes. The asymptotic normalization
coefficient (ANC) method is used to extract S17(0) from the calculated
breakup-cross-section. The main result of the present paper is S17(0)=20.9
+2.0/-1.9 eV b. The error consists of 8.4% experimental systematic error and
the error due to the ambiguity in the s-wave p-7Be scattering length. This
value of S17(0) differs from the one extracted with the first-order
perturbation theory including Coulomb breakup by dipole transitions: 18.9 +/-
1.8 eV b. It turns out that the difference is due to the inclusion of the
nuclear and Coulomb-quadrupole transitions and multi-step processes of
all-order in the present work. The p-7Be interaction potential used in the CDCC
calculation is also used in the ANC analysis of 7Be(p,\gamma)8B. The value of
S17(0)=21.7 +0.62/-0.55 eV b obtained is consistent with the previous one
obtained from a precise measurement of the p-capture reaction cross section
extrapolated to zero incident energy, S17(0)=22.1 +/- 0.6 (expt) +/- 0.6 (theo)
eV b, where (theo) stands for the error in the extrapolation. Thus, the
agreement between the values of S17(0) obtained from direct 7Be(p,\gamma)8B and
indirect 8B-breakup measurements is significantly improved.Comment: 13 pages, 9 figures, published in PR
Quantum limits of super-resolution in reconstruction of optical objects
We investigate analytically and numerically the role of quantum fluctuations
in reconstruction of optical objects from diffraction-limited images. Taking as
example of an input object two closely spaced Gaussian peaks we demonstrate
that one can improve the resolution in the reconstructed object over the
classical Rayleigh limit. We show that the ultimate quantum limit of resolution
in such reconstruction procedure is determined not by diffraction but by the
signal-to-noise ratio in the input object. We formulate a quantitative measure
of super-resolution in terms of the optical point-spread function of the
system.Comment: 23 pages, 7 figures. Submitted to Physical Review A e-mail:
[email protected]
New effective nuclear forces with a finite-range three-body term and their application to AMD+GCM calculations
We propose new effective inter-nucleon forces with a finite-range three-body
operator. The proposed forces are suitable for describing the nuclear structure
properties over a wide mass number region, including the saturation point of
nuclear matter. The forces are applied to microscopic calculations of
() nuclei and O isotopes with a method of antisymmetrized molecular
dynamics. We present the characteristics of the forces and discuss the
importance of the finite-range three-body term.Comment: 15 pages, 11 figures, submitted to Phys.Rev.
Biospecific Affinity Chromatography: Computational Modelling via Lattice Boltzmann Method and Influence of Lattice-Based Dimensionless Parameters
Based on a dynamic (i.e. time-dependent) one-dimensional approach, this work applied lattice Boltzmann method (LBM) to computationally model biospecific affinity chromatography (BAC). With governing equations expressed in lattice-based dimensionless form, LBM was implemented in D1Q2 lattice by assigning particle distribution functions to adsorbate concentration in both fluid and solid phases. The LBM simulator was firstly tested in view of a classic BAC work on lysozyme and the streaming step relating to adsorbate concentration in the solid-phase was suppressed from the LBM code with no loss of functionality. Expected behaviour of breakthrough curves was numerically reproduced and the influence of lattice-based dimensionless parameters was examined. The LBM simulator was next applied so as to assess lattice-based dimensionless parameters regarding an experimental BAC work on lipase
Quantum-Enhanced Heat Engine Based on Superabsorption
We propose a quantum-enhanced heat engine with entanglement. The key feature
of our scheme is superabsorption, which facilitates enhanced energy absorption
by entangled qubits. Whereas a conventional engine with separable qubits
provides power with a scaling of , our engine uses
superabsorption to provide power with a quantum scaling of .
This quantum heat engine also exhibits a scaling advantage over classical ones
composed of -particle Langevin systems. Our work elucidates the quantum
properties allowing for the enhancement of performance
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