Endogenous processes such as biomass decay and intracellular polymers degradation of polyphosphate-accumulating organisms (PAOs) and glycogen-accumulating organisms (GAOs) were investigated. Cultures enriched in Accumulibacter (a well known PAO) or Competibacter (a well known GAO) were subjected to 21 and 26 days of alternating anaerobic/aerobic conditions respectively. The main energy source f...

The decay rate of orthopositronium (o-Ps) formed and thermalized in eight different gases is systematically investigated as a function of temperature. The o-Ps collisional quenching rate is observed to increase with temperature, T , for He, Ne, Ar, N2, ethane, methane, isobutane and neopentane. All of the gases except ethane and methane increase linearly over the investigated temperature range,...

In solids the phonon-assisted, nonradiative decay from high-energy electronic excited states to low-energy electronic excited states is picosecond fast. It was hoped that electron and hole relaxation could be slowed down in quantum dots, due to the unavailability of phonons energy matched to the large energy-level spacings ("phonon-bottleneck"). However, excited-state relaxation was observed to...

Abstract. In this paper we consider the transmission problem of a material composed of three components; one of them is a Kelvin–Voigt viscoelastic material, the second is an elastic material (no dissipation), and the third is an elastic material inserted with a frictional damping mechanism. The main result of this paper is that the rate of decay will depend on the position of each component. W...

In this paper we investigate the e ciency of the method of Perfectly Matched Layers (PML) for the 1-d wave equation. The PML method furnishes a way to compute solutions of the wave equation for exterior problems in a nite computational domain by adding a damping term on the matched layer. In view of the properties of solutions in the whole free space, one expects the energy of solutions obtaine...

We study the low-energy dynamics of an acoustic black hole near the sonic horizon. For the experimental test of black hole evaporation in the laboratory, the decay rate (greybody factor) of the acoustic black hole (sonic hole) can be calculated by the usual low-energy perturbation method. As a consequence, we obtain the decay rate of the sonic horizon from the absorption and the reflection coef...

1. I N T R O D U C T I O N A N D M A I N R E S U L T In this work, we s tudy the stabilization of one-dimensional wave equations with a dynamical control Ytt -Yxz ---O, 0 ~ X ~ 1, y(0, t) = 0, yx(1, t ) + ~(t) = 0, (1.1) ~t(t) : yt(1, t) + ~?(t) = O, where ~ denotes the dynamical control and ~ is a positive constant. The dynamical control has been introduced in the finite-dimensional case (ordi...

In this paper, we study uniform exponential stabilization of the vibrations of the Kirchhoff type wave equation with acoustic boundary in a bounded domain in Rn. To stabilize the system, we incorporate separately, the passive viscous damping in the model as like Gannesh C. Gorain [1]. Energy decay rate is obtained by the exponential stability of solutions by using multiplier technique.