8,160 research outputs found
Reentrant phase transitions and triple points of topological AdS black holes in Born-Infeld-massive gravity
Motivated by recent developments of black hole thermodynamics in de Rham,
Gabadadze and Tolley(dRGT) massive gravity, we study the critical behaviors of
four-dimensional topological Anti-de Sitter(AdS) black holes in the presence of
Born-Infeld nonlinear electrodynamics by treating the cosmological constant as
pressure and the corresponding conjugate quantity is interpreted as
thermodynamic volume. It shows that besides the Van der Waals-like SBH/LBH
phase transitions appears, the so-called reentrant phase transitions (RPTs) are
also observed when the coupling coefficients of massive potential and
Born-Infeld parameter satisfy some certain conditions.Comment: arXiv admin note: text overlap with arXiv:1612.08056; text overlap
with arXiv:1402.2837, arXiv:1306.5756 by other autho
The Effects on , , and from Higher-Dimensional Fermion Representations
Inspired by a new class of walking technicolor models recently proposed using
higher-dimensional technifermions, we consider the oblique corrections from
heavy non-degenerate fermions with two classes of higher-dimensional
representations of the electroweak gauge group itself. One is chiral SM-like,
and the other is vector-like. In both cases, we obtain explicit expressions for
, , in terms of the fermion masses. We find that to keep the
parameter ultraviolet-finite there must be a stringent constraint on the mass
non-degeneracy of a heavy fermion multiplet.Comment: 4 page
Linear active disturbance rejection control of waste heat recovery systems with organic Rankine cycles
In this paper, a linear active disturbance rejection controller is proposed for a waste heat recovery system using an organic Rankine cycle process, whose model is obtained by applying the system identification technique. The disturbances imposed on the waste heat recovery system are estimated through an extended linear state observer and then compensated by a linear feedback control strategy. The proposed control strategy is applied to a 100 kW waste heat recovery system to handle the power demand variations of grid and process disturbances. The effectiveness of this controller is verified via a simulation study, and the results demonstrate that the proposed strategy can provide satisfactory tracking performance and disturbance rejection
Predictive PDF control in shaping of molecular weight distribution based-on a new modelling Algorithm
The aims of this work are to develop an efficient modeling method for establishing dynamic output probability density function (PDF) models using measurement data and to investigate predictive control strategies for controlling the full shape of output PDF rather than the key moments. Using the rational square-root (RSR) B-spline approximation, a new modeling algorithm is proposed in which the actual weights are used instead of the pseudo weights in the weights dynamic model. This replacement can reduce computational load effectively in data-based modeling of a high-dimensional output PDF model. The use of the actual weights in modeling and control has been verified by stability analysis. A predictive PDF model is then constructed, based on which predictive control algorithms are established with the purpose to drive the output PDF towards the desired target PDF over the control process. An analytical solution is obtained for the non-constrained predictive PDF control. For the constrained predictive control, the optimal solution is achieved via solving a constrained nonlinear optimization problem. The integrated method of data-based modeling and predictive PDF control is applied to closed-loop control of molecular weight distribution (MWD) in an exemplar styrene polymerization process, through which the modeling efficiency and the merits of predictive control over standard PDF control are demonstrated and discussed
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