Mixtures of distributions are usually effectively used for modeling heterogeneity. It is well known that mixtures of DFR distributions are always DFR. On the other hand, mixtures of IFR distributions can decrease, at least in some intervals of time. As IFR distributions often model lifetimes governed by ageing processes, the operation of mixing can dramatically change the pattern of ageing. The...

In this paper we consider nonparametric estimation for dependent data, where the observations do not necessarily come from a linear process. We study density estimation and also discuss associated problems in nonparametric regression using the 2-mixing dependence measure. We compare the results under 2-mixing with those derived under the assumption that the process is linear. In the context of ...

Let (Ω,A, μ) be a Lebesgue space and T : Ω → Ω an ergodic measure preserving automorphism with positive entropy. We show that there is a bounded and strictly stationary martingale difference sequence defined on Ω with a common non-degenerate lattice distribution satisfying the central limit theorem with an arbitrarily slow rate of convergence and not satisfying the local limit theorem. A simila...

Process development, cheaper bioreactor cost, and faster fermentation rate can aid in reducing the cost of fermentation. In this article, these ideas were combined in developing a previously introduced textile bioreactor for ethanol production. The bioreactor was developed to utilize flocculating yeast for ethanol production under anaerobic conditions. A mixing system, which works without aerat...

We present the first bit-error-rate characterization of silicon four-wave-mixing wavelength converters. Power penalties below 0.5 dB are demonstrated over a 20-nm EDFA-limited wavelength range at 10 Gb/s, while 40-Gb/s measurements yield a 2.4-dB power penalty. ©2008 Optical Society of America OCIS codes: (130.7405) Wavelength conversion devices; (190.4380) Nonlinear optics, four-wave mixing

We experimentally demonstrate, for the first time, polarization-insensitive wavelength conversion of a 10 Gb/s NRZ-OOK data signal based on four-wave mixing in a silicon nanowire with bit-error rate measurements. OCIS codes: (190.4380) Nonlinear optics, four-wave mixing; (190.4390) Nonlinear optics, integrated optics; (230.7370) Waveguide; (130.7405) Wavelength conversion devices.

Two-dimensional bidisperse foams were simulated in cyclic, uniaxial, extensional shear. Mixing of bubbles of different sizes only occurs at high strains, and once mixed, the bubbles do not segregate. For liquid fractions up to 1%, the rate of mixing is shown to be slightly enhanced by increased liquid fraction.

We prove that the spectral gap of the Kawasaki dynamics shrink at the rate of I lL 2 for cubes of size L provided that some mixing conditions are satisfied. We also prove that the logarithmic Sobolev inequality for the Glauber dynamics in standard cubes holds uniformly in the size of the cube if the Dobrushin-Shlosman mixing condition holds for standard cubes.

background and aims: chromium is considered as one of the important environmental pollutants. there is high concentration of chromium in the wastewater of electroplating industries. magnetic iron nanoparticles are used to control and eliminate heavy metals from industrial effluents through the mechanisms of adsorption, ion exchange and electro-static forces. the aim of this study was to evaluat...