This investigation deals with the numerical simulation of entropy generation at mixed convection flow in a lid-driven saturated porous cavity submitted to a magnetic field. The magnetic field is applied in the direction that is normal to the cavity cross section. The governing equations, written in the Darcy–Brinkman–Forchheimer formulation, are solved using a numerical code based on the Contro...

Random and pseudorandom number generators (RNG and PRNG) are used for many purposes including cryptographic, modeling and simulation applications. For such applications a generated bit sequence should mimic true random, i.e., by definition, such a sequence could be interpreted as the result of the flips of a fair coin with sides that are labeled 0 and 1. It is known that the Shannon entropy of ...

We investigate entropy generation in unsteady three-dimensional axisymmetric MHD nanofluid flow over a non-linearly stretching sheet. The flow is subject to thermal radiation and a chemical reaction. The conservation equations were solved using the spectral quasi-linearization method. The novelty of the work is in the study of entropy generation in three-dimensional axisymmetric MHD nanofluid a...

in this paper, convection heat transfer of al2o3-water nanofluid turbulent flow through internally ribbed tubes with different rib shapes (rectangular, trapezoidal and semi-circular) is numerically investigated. for each rib shape, the optimum geometric ratio and volume fraction were calculated using entropy generation minimization technique. the governing equations in steady state and axisymme...

The random number generator (RNG) is a critical, if not in fact the most important, component in every cryptographic device. Introducing the symmetric radio channel, represented by estimations of location-specific, reciprocal, and timevariant channel characteristics, as a common RNG is not a trivial task. In recent years, several practice-oriented protocols have been proposed, challenging the u...

This paper presents a new design of open parallel microchannels embedded within a permeable continuous moving surface due to reduction of exergy losses in magnetohydrodynamic (MHD) flow at a prescribed surface temperature (PST). The entropy generation number is formulated by an integral of the local rate of entropy generation along the width of the surface based on an equal number of microchann...

The main component of a true random number generator (TRNG) is its source of entropy. Field Programmable Gate Arrays (FPGAs) are emerging as a popular platform for implementing single-chip TRNGs. Most of the generators implemented in FPGAs exploit the jitter from ring oscillators as source of entropy. The present paper proposes a new method for implementing TRNGs in FPGAs based on high fanout c...

The Linux [1] random number generator (LRNG) aims to produce random numbers with all the limitations due to a deterministic machine. Two recent analysis exist for this generator [2,5]. These analysis provide strong cryptographic details about LRNG. However both fail to give a mathematical explanation of the entropy estimator embedded. In this paper we propose an interpretation using Newton poly...

Jittery clock signals produced in oscillators, particularly in ring oscillators are commonly used as a source of randomness in true random number generators (TRNG). The robustness of the generators, and hence their security, is closely linked to the entropy of the generated bit stream, which depends on the size of the jitter. Known jitter size can be used as an input parameter in a stochastic m...

Entropy generation for natural convection in a partitioned cavity, with adiabatic horizontal and isothermally cooled vertical walls, is studied numerically by both a FORTRAN code and the commercially available CFD-ACE software. Effects of the Rayleigh number, the position of the heated partition, and the dimensionless temperature difference on the local and average entropy generation rate are i...