in the present study, natural convective heat transfer in a partitioned square cavity utilizing nanofluids is studied. the vertical left and right walls are considered as the hot and cold walls, respectively and the partitions assumed to be adiabatic. the nanofluid used in this study is al2o3 with the volume fraction of 20%. it is assumed that nanofluid is a single phase fluid. fluent 6.3.26 is...

The retransmission cut-off is not needed for a stable operation of slotted ALOHA if the new packet generation rate is below a critical limit. The throughput never reaches its maximum value if the new packet generation rate is less than this critical limit irrespective of the number of transmissions. The maximum throughput is attained by adjusting the number of transmissions, pertaining to the n...

The underground muon flux produced by primary cosmic rays with a median rigidity of 1.5 x 10 V has been monitored to search for periodic and transient rate variations. The detector has operated at an average rate of 4.47 Hz for most of the 1.2 yr interval starting 1978 Jan 1. A peak with relative amplitude (3.8 ± 0.9) x10 -4 is observed in the Fourier transform of data at the sidereal 0.9 frequ...

Conventional light microscopy is limited in its resolving power by the Rayleigh limit to length scales on the order of 200 nm. On the other hand, spectroscopic techniques such as fluorescence resonance energy transfer cannot be used to measure distances >10 nm, leaving a "gap" in the ability of optical techniques to measure distances on the 10- to 100-nm scale. We have previously demonstrated t...

We develop, analyse and numerically simulate a model of a prototype, glucose-driven, rhythmic drug delivery device, aimed at hormone therapies, and based on chemomechanical interaction in a polyelectrolyte gel membrane. The pH-driven interactions trigger volume phase transitions between the swollen and collapsed states of the gel. For a robust set of material parameters, we find a class of solu...

We study the stability of the system of the Euler equations in the neighborhood of the stationary solution associated with the quasi isobaric profile in a gravity field. This situation corresponds to a Rayleigh-Taylor type problem with a smooth base density profile which goes from 0 to ρa (of Atwood number A = 1) given by the ablation front model with a thermal conductivity exponent ν > 1. This...

In this chapter, we are interested in the ultimate limit on the rate of reliable communication over Rayleigh-fading channels that satisfy the wide-sense stationary (WSS) and uncorrelated scattering (US) assumptions and are underspread [Bel63, Ken69]. Therefore, the natural setting is an information-theoretic one, and the performance metric is channel capacity [CT91, Gal68]. The family of Raylei...

We present radio, optical, ultraviolet, and X-ray observations of the isolated, thermally-emitting neutron star RX J0720.4−3125 using the Parkes radio telescope, the Very Large Array, the Hubble Space Telescope, and the Chandra X-ray Observatory. From these data we show that the optical/UV spectrum of RX J0720.4−3125 is not well fit by a Rayleigh-Jeans tail as previously thought, but is instead...

We analyse and improve a recently-proposed two-phase ow model for the statistical evolution of two-uid mixing. A hyperbolic equation for the volume fraction, whose characteristic speed is the average interface velocity v , plays a central role. We propose a new model for v in terms of the volume fraction and uid velocities, which can be interpreted as a constitutive law for two-uid mixing. In t...