Influence of the driving mechanism on the response of systems with athermal dynamics: the example of the random-field Ising model

We investigate the influence of the driving mechanism on the hysteretic response of systems with athermal dynamics. In the framework of local-mean field theory at finite temperature (but neglecting thermallly activated processes), we compare the rate-independent hysteresis loops obtained in the random field Ising model (RFIM) when controlling either the external magnetic field $H$ or the extensive magnetization $M$. Two distinct behaviors are observed, depending on disorder strength. At large disorder, the $H$-driven and $M$-driven protocols yield identical hysteresis loops in the thermodynamic limit. At low disorder, when the $H$-driven magnetization curve is discontinuous (due to the presence of a macroscopic avalanche), the $M$-driven loop is re-entrant while the induced field exhibits strong intermittent fluctuations and is only weakly self-averaging. The relevance of these results to the experimental observations in ferromagnetic materials, shape memory alloys, and other disordered systems is discussed.Comment: 11 pages, 11 figure

Vortex distribution in the Lowest Landau Level

We study the vortex distribution of the wave functions minimizing the Gross Pitaevskii energy for a fast rotating condensate in the Lowest Landau Level (LLL): we prove that the minimizer cannot have a finite number of zeroes thus the lattice is infinite, but not uniform. This uses the explicit expression of the projector onto the LLL. We also show that any slow varying envelope function can be approximated in the LLL by distorting the lattice. This is used in particular to approximate the inverted parabola and understand the role of ``invisible'' vortices: the distortion of the lattice is very small in the Thomas Fermi region but quite large outside, where the "invisible" vortices lie.Comment: 4 pages, 1 figur

Cyclic feeding of low and high protein diets reduces production cost of Labeo rohita (Hamilton, 1822)

Eighty four days feeding trial (3 feeding cycle ; each cycle of 28 days comprising 21 days with low protein and 7 days with normal or high protein diets) was conducted with Labeo rohita fingerlings to investigate the growth performance. Four diets; D1 (10% CP); D2 (30% CP); D3 (35% CP) and D4 (40% CP) were prepared. A total of 225 fingerlings were distributed randomly into five treatments in triplicates. T1 and T2 groups were fed with D1 and D2 diets respectively throughout the experimental period. The feeding cycle of 28 days consisted of 21 days feeding with D1 and 7 days with D2 (T3); D3 (T4) or D4 (T5). Higher growth rate in terms of specific growth rate, feed conversion ratio and apparent net protein utilisation were found in T2 and T3 group compared to T4 and T5. However, protein efficiency ratio of T3 group was significantly higher than the T2 group (p<0.05). Highest and lowest content of protein and lipid was observed in T2 group, whereas, the ash content was highest in T1 group. Feeding cost was considerably reduced with T3 group of low protein intake (43.63%) registering 20.17% saving in production cost. The results indicate that fish fed with cyclic feeding schedule of 21 days with D1 (10% CP) followed by 7 days with a normal diet, D2 (30% CP) could reduce the production cost with considerable savings in feed cost

Future challenges in cephalopod research

We thank Anto´nio M. de Frias Martins, past President of the Unitas Malacologica and Peter Marko, President of the American Malacological Society for organizing the 2013 World Congress of Malacology, and the Cephalopod International Advisory Committee for endorsing a symposium held in honour of Malcolm R. Clarke. In particular, we would like to thank the many professional staff from the University of the Azores for their hospitality, organization, troubleshooting and warm welcome to the Azores. We also thank Malcolm Clarke’s widow, Dorothy, his daughter Zoe¨, Jose´ N. Gomes-Pereira and numerous colleagues and friends of Malcolm’s from around the world for joining us at Ponta Delgada. We are grateful to Lyndsey Claro (Princeton University Press) for granting copyright permissions.Peer reviewedPublisher PD

Neural Modeling and Control of Diesel Engine with Pollution Constraints

The paper describes a neural approach for modelling and control of a turbocharged Diesel engine. A neural model, whose structure is mainly based on some physical equations describing the engine behaviour, is built for the rotation speed and the exhaust gas opacity. The model is composed of three interconnected neural submodels, each of them constituting a nonlinear multi-input single-output error model. The structural identification and the parameter estimation from data gathered on a real engine are described. The neural direct model is then used to determine a neural controller of the engine, in a specialized training scheme minimising a multivariable criterion. Simulations show the effect of the pollution constraint weighting on a trajectory tracking of the engine speed. Neural networks, which are flexible and parsimonious nonlinear black-box models, with universal approximation capabilities, can accurately describe or control complex nonlinear systems, with little a priori theoretical knowledge. The presented work extends optimal neuro-control to the multivariable case and shows the flexibility of neural optimisers. Considering the preliminary results, it appears that neural networks can be used as embedded models for engine control, to satisfy the more and more restricting pollutant emission legislation. Particularly, they are able to model nonlinear dynamics and outperform during transients the control schemes based on static mappings.Comment: 15 page

N′-[(1E)-3-Bromo-5-chloro-2-hy­droxy­benzyl­idene]-4-tert-butyl­benzo­hydrazide ethanol monosolvate

In the title compound, C18H18BrClN2O2·C2H6O, the hy­droxy group forms an intra­molecular O—H⋯N hydrogen bond, which influences the conformation of the Shiff base mol­ecule, where the two aromatic rings form a dihedral angle of 21.67 (8)°. Inter­molecular N—H⋯O and O—H⋯O hydrogen bonds link two Shiff base mol­ecules and two solvent mol­ecules into a centrosymmetric heterotetra­mer. Weak inter­molecular C—H⋯O inter­actions link further tetra­mers related by translation along the a axis into chains

Model dependence of the neutron-skin thickness on the symmetry energy

The model dependence in the correlations of the neutron-skin thickness in heavy nuclei with various symmetry-energy parameters is analyzed by using several families of systematically varied microscopic mean-field models. Such correlations show a varying degree of model dependence once the results for all the different families are combined. Some mean-field models associated with similar values of the symmetry-energy slope parameter at saturation density L , and pertaining to different families, yield a greater-than-expected spread in the neutron-skin thickness of the 208 Pb nucleus. The effective value of the symmetry-energy slope parameter L eff , determined by using the nucleon density profiles of the finite nucleus and the density derivative S ′ ( ρ ) of the symmetry energy starting from about saturation density up to low densities typical of the surface of nuclei, seems to account for the spread in the neutron-skin thickness for the models with similar L . The differences in the values of L eff are mainly due to the small differences in the nucleon density distributions of heavy nuclei in the surface region and the behavior of the symmetry energy at subsaturation densities

A Spectroscopic Survey of Electronic Transitions of C6_6H, 13^{13}C6_6H, and C6_6D

Electronic spectra of C$_6$H are measured in the $18\,950-21\,100$ cm$^{-1}$ domain using cavity ring-down spectroscopy of a supersonically expanding hydrocarbon plasma. In total, 19 (sub)bands of C$_6$H are presented, all probing the vibrational manifold of the B$^2\Pi$ electronically excited state. The assignments are guided by electronic spectra available from matrix isolation work, isotopic substitution experiments (yielding also spectra for $^{13}$C$_6$H and C$_6$D), predictions from ab initio calculations as well as rotational fitting and vibrational contour simulations using the available ground state parameters as obtained from microwave experiments. Besides the $0_0^0$ origin band, three non-degenerate stretching vibrations along the linear backbone of the C$_6$H molecule are assigned: the $\nu_6$ mode associated with the C-C bond vibration and the $\nu_4$ and $\nu_3$ modes associated with C$\equiv$C triple bonds. For the two lowest $\nu_{11}$ and $\nu_{10}$ bending modes, a Renner-Teller analysis is performed identifying the $\mu^2\Sigma$($\nu_{11}$) and both $\mu^2\Sigma$($\nu_{10}$) and $\kappa^2\Sigma$($\nu_{10}$) components. In addition, two higher lying bending modes are observed, which are tentatively assigned as $\mu^2\Sigma$($\nu_9$) and $\mu^2\Sigma$($\nu_8$) levels. In the excitation region below the first non-degenerate vibration ($\nu_6$), some $^2\Pi-^{2}\Pi$ transitions are observed that are assigned as even combination modes of low-lying bending vibrations. The same holds for a $^2\Pi-^{2}\Pi$ transition found above the $\nu_6$ level. From these spectroscopic data and the vibronic analysis a comprehensive energy level diagram for the B$^2\Pi$ state of C$_6$H is derived and presented.Comment: Accepted for publication in The Journal of Physical Chemistry A (26 July 2016

Mixed feeding schedule of low and high protein in the diet of Labeo rohita (Hamilton) fingerlings: effect on growth performance, haemato-immunological and stress responses

Four experimental diets D1, D2, D3 and D4 having 100, 300, 350 and 400 g protein kg−1 diet, respectively, were prepared. Fingerlings of Labeo rohita (5.45 ± 0.03 g) were fed with different diets following a mixed feeding schedule with the feeding cycle of 28 days that consisted of either 28 days feeding of diet D1 or D2 or 21 days feeding with D1 diet and 7 days with either D3 or D4 diet. Different treatments were T1 (D1 for 28 days), T2 (D2 for 28 days), T3 (D1 for 21 days and D2 for 7 days), T4 (D1 for 21 days and D3 for 7 days) or T5 (D1 for 21 days and D4 for 7 days). Fingerlings were sampled after three feeding cycles (84 days). Higher (P < 0.05) growth performance and protein utilization efficiency were found in the T3 group, which was similar to the T2 group. The blood count, NBT, lysozyme activity, serum parameters and stress indicator parameters also complement for the better immunity in the T2 and T3 groups. Therefore, it could be concluded that fingerlings feeding alternately a low-protein diet (D1) for 21 days followed by a normal-protein diet (D2) for 7 days in a cycle of 28 days for 84 days maintained better growth and health status

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