On Continuous Full-Order Integral-Terminal Sliding Mode Control with Unknown Apriori Bound on Uncertainty

This study aims at providing a solution to the problem of designing a continuous and finite-time control for a class of nonlinear systems in the presence of matched uncertainty with an unknown apriori bound. First, we propose a Full-Order Integral-Terminal Sliding Manifold (FOITSM) with a conventional (discontinuous) sliding mode to show that it provides the combined attributes of the nonsingular terminal and integral sliding mode algorithms. Secondly, an Adaptive Disturbance Observer (ADO) has been designed to alleviate the effect of the uncertainty acting on the system. On application of the ADO-based Full-Order Integral-Terminal Sliding Mode Control (FOITSMC), the chattering phenomenon in control input has been reduced substantially in the presence of conditionally known matched disturbances. Moreover, the adaptive gains of ADO are updated non-monotonically without over-bounding the acting disturbance, yet sustain the global boundedness of state trajectories within a specific bound. %Finally, an application of the proposed algorithm for attitude stabilization of a rigid spacecraft has been successively shown.Comment: 14 pages, 9 figure

Determination of equation of state of quark matter from J/ψJ/\psi and Υ\Upsilon suppression at RHIC and LHC

The long life-time of the quark-gluon plasma likely to be created in the relativistic heavy ion collisions at RHIC and LHC energies renders it sensitive to the details of the equation of state of the quark-matter. We show that the $p_T$ dependence of the survival probability of the directly produced $J/\psi$ at RHIC energies and that of the directly produced $\Upsilon$ at LHC energies is quite sensitive to the speed of sound in the quark matter, which relates the pressure and the energy density of the plasma. The transverse expansion of the plasma is shown to strongly affect the $J/\psi$ suppression at LHC energies.Comment: 26 pages including 11 figures. (Submitted to Eur. Phys. Jour. C

Hydrogen bonded molecular rectangle of N,N-bis(3-quinolyl- methylene)diphenylethanedionedihydrazone

416-419The title compound, N,N-bis (3-quinolylmethylene) diphenylethanedionedihydrazone (I) (molecular formula, C34H24N6) has been synthesized by the reaction of quinoline 3-carboxaldehyde and diphenylethanedionedihydrazone in 2:1 molar ratio. The molecular structure has been characterized by room-temperature single-crystal X-ray diffraction which reveals that two quinoline moieties are disposed nearly perpendicularly around the central C-C bond giving an ‘L’ shape to the molecule. This particular geometry gives rise to the hydrogen bonded supramolecular rectangle of two self-complementary molecules. These supramolecular units are further assembled by - interaction

J/ψJ/\psi suppression: gluonic dissociation {\em vs.} colour screening

We evaluate the suppression of $J/\psi$ production in an equilibrating quark gluon plasma for two competing mechanisms: Debye screening of colour interaction and dissociation due to energetic gluons. Results are obtained for $S+S$ and $Au+Au$ collisions at RHIC and LHC energies. At RHIC energies the gluonic dissociation of the charmonium is found to be equally important for both the systems while the screening of the interaction plays a significant role only for the larger systems. At LHC energies the Debye mechanism is found to dominate for both the systems. While considering the suppression of directly produced $\Upsilon$ at LHC energies, we find that only the gluonic dissociation mechanism comes into play for the initial conditions taken from the self screened parton cascade model in these studies. Thus we find that a systematic study of quarkonium suppression for systems of varying dimensions can help identify the source and the extent of the suppression.Comment: (revised) 5 pages including 3 figures, discussion expande

Evolution of strangeness in equilibrating and expanding quark-gluon plasma

We evaluate the strangeness production from equilibrating and transversely expanding quark gluon plasma which may be created in the wake of relativistic heavy ion collisions. We consider boost invariant longitudinal and cylindrically symmetric transverse expansion of a gluon dominated partonic plasma, which is in local thermal equilibrium. Initial conditions obtained from the self screened parton cascade model are used. We empirically find that the final extent of the partonic equilibration rises almost linearly with the square of the initial energy density. This along with the corresponding variation with the number of participants may help us distinguish between various models of parton production.Comment: RevTex, 10 pages including 6 figures comprising 11 postscript files, text modified considerably with an added figure (Fig. 6) and this version accepted for publication in Phys. Rev.