Effect Of Random Distribution Research Articles

EFFECT OF RANDOM DISTRIBUTION AND SHORT-RANGE ORDERING OF SOLUTES ON THE MECHANICAL PROPERTIES OF NANOCRYSTALLINE Cu–Ag ALLOYS

The effects of solute random distribution (RSS) before relaxation and solute short-range ordering (SRO) after relaxation on the mechanical behavior of nanocrystalline Cu–Ag alloys were analyzed by molecular dynamics simulation. It has been found that the mechanical properties of Cu–Ag alloy mechanics with SRO were better than those of Cu–Ag alloy mechanics with RSS. Specifically, during the whole tensile process, compared with sample #1 with SRO structure, sample #2 with RSS structure has stronger strain–stress response ability, more obvious phase transformation process, and narrower shear strain zone on the grain boundary. Furthermore, when the number of Voronoi seeds is examined concerning the mechanical properties of the nanocrystalline Cu–Ag alloy, it becomes apparent that the average flow stress drops as the quantity of Voronoi seeds increases.

Enhancement of superior dielectric performance in ZnTiNb2O8 systems by multi‐layer architecture

AbstractZn0.995Cu0.005TiNb2O8@TiO2 mixed ceramics and Zn0.995Cu0.005TiNb2O8‐TiO2‐Zn0.995Cu0.005TiNb2O8 layered ceramics with different TiO2 contents were designed and manufactured to adjust the microwave dielectric performances of Zn0.995Cu0.005TiNb2O8/TiO2 composite ceramics. The effects of random distribution and laminated co‐firing processes on the microwave dielectric properties of the ZnTiNb2O8 systems were fully investigated and compared. During the random distribution process, the compound transforms from the original ZnTiNb2O8 phase to the Zn0.17Nb0.33Ti0.5O2 phase with the increase of TiO2 content. Its value can be adjusted to near zero, but its Q× f value decreases severely. For the laminated co‐firing process, the distinctive tri‐layer architecture allows the reaction between Zn0.995Cu0.005TiNb2O8 and TiO2 to be limited to a narrow region of about 20 µm width and can play a role similar to that of “glue” to connect the layers well. The process significantly minimizes the probability of Q× f values deteriorating. Compared with the random distribution Zn0.995Cu0.005TiNb2O8@TiO2, the Q× f value of the tri‐layer architecture ceramics is improved by about 85% with no significant decrease in dielectric permittivity while ensuring high‐temperature stability. When stacked with 0.04 wt% TiO2, the Zn0.995Cu0.005TiNb2O8‐TiO2‐Zn0.995Cu0.005TiNb2O8 tri‐layer architecture ceramic exhibits superior dielectric properties: = 39.96, Q× f = 51,987 GHz, and = ‐1.31 ppm/°C.

Effects of the Random Distributions on the Laminar Flow and Heat Transfer in a Quasi-Counter Flow Parallel-Plate Membrane Channel

ABSTRACTAn internally cooled parallel-plate membrane contactor has been employed for liquid desiccant air dehumidification. The contactor is comprised of a series of quasi-counter flow parallel-plate membrane channels (QCPMC). The processing air and the liquid desiccant (solution) streams are separated by the membranes. Cooling tubes are installed in the solution channel to take away the absorption heat. The laminar flow and heat transfer in the QCPMC with the cooling tubes in the solution side (QCPMCC) are studied based on a unit cell containing the sandwiched domain outside the cooling tubes between two neighboring membranes. This paper is focused on the effects of the random distributions in the height direction on the transport phenomena in the QCPMCC. The governing equations of the momentum and thermal transports are built up together with a uniform wall temperature boundary condition. The product of the mean friction factor and Reynolds number and the mean Nusselt number are then calculated. Effects of the various random distributions in the height direction on the product of the mean friction factor and Reynolds number and the mean Nusselt number are analyzed. Compared to the regular arrangement, the mean Nusselt number for the random distribution is larger than that for the regular one when the Reynolds number is less than 68.5. However when the Reynolds number is larger than 68.5, the mean Nusselt number for the random distribution is smaller than that for the regular one.

Following Car Algorithm With Multi Agent Randomized System

We present a new Following Car Algorithm in Microscopic Urban Traffic Models which integrates some real-life factors that need to be considered, such as the effect of random distributions in the car speed, acceleration, entry of lane… Our architecture is based on Multi-Agent Randomized Systems (MARS) developed in earlier publications.

The Multi-Agent System and Scholastic Process in the Road Traffic

In recent ‎‎ the rapid growth of road traffic density ‎a rising request for tools that can be used to analyze and ‎the traffic networks. The Microscopic traffic simulation is one of the major tools used in the analysis of traffic systems; it provides a very detailed study of the interaction between the elements of the traffic network. Thus microscopic traffic simulation has become an ever increasing field of research and development.‎ The main aim if this paper is to provide a new model for microscopic traffic simulation; Traditional traffic simulation models neglect some real-life factors that need to be ‎ such as the effect of random distribution in ‎entry of lane. This paper combines the ‎-Agent Systems ‎ (MAS) ‎ and the stochastic process to model the randomness of vehicles arrival at the entry of the lane. ‎second contribution of this paper is about the internal structure of mobile agents[8] which initially reacts ‎to the instructions of the Main agent (MA); in the case of a lack of dynamic information, ‎mobile agents take decisions based on their experiences accumulated during previous interactions. The obtained results illustrate that using the randomness in the reaction of agent enhanced greatly the performance of simulation.

Effect of Interface Anisotropy on Elastic Wave Propagation in Particulate Composites

ABSTRACTThe scattering of time harmonic plane longitudinal and transverse elastic waves in a composite consisting of randomly distributed identical isotropic spherical inclusions embedded in an isotropic matrix with anisotropic interface layers is examined. The interface region is modeled as a spherically isotropic shell of finite thickness with five independent elastic constants. The Frobenius power series solution method is utilized to deal with the interface anisotropy and the effect of random distribution of particulates in the composite medium is taken into account via a recently developed generalized self-consistent multiple scattering model. Numerical values of phase velocities and attenuations of coherent plane waves as well as the effective elastic constants are obtained for a moderately wide range of frequencies, particle concentrations, and interface anisotropies. The numerical results reveal the significant dependence of phase velocities and effective elastic constants on the interface properties. They show that interface anisotropy can moderately depress the effective phase velocities and the elastic moduli, but leave effective attenuation nearly unaffected, especially at low and intermediate frequencies. Limiting cases are considered and good agreements with recent solutions have been obtained.

Local structural distortions and Mn random distributions in (Ga,Mn)As: A first-principles study

The effect of random distribution of Mn atoms on the electronic and magnetic properties of ${\mathrm{Ga}}_{1\ensuremath{-}x}{\mathrm{Mn}}_{x}\mathrm{As}$ with $x=0.0625$ is studied with Vienna ab initio simulation package. We use a $2\ifmmode\times\else\texttimes\fi{}2\ifmmode\times\else\texttimes\fi{}2$ supercell, in which 64 atoms are included, and two Mn atoms substitute Ga positions. Five different Mn-Mn configurations are considered. Local structural relaxations show that the bond lengths of Mn-As are smaller than those of the nearby Ga-As. The total-energy calculation indicates that because of the inhomogeneous spatial distribution of holes, the ferromagnetic interaction between two Mn ions strongly depends on the direction along the two Mn ions. The inhomogeneous distribution of Mn atoms makes the holes stay in slightly stronger localized states. The value of magnetic moments and their spatial distributions are slightly affected by random distribution of Mn atoms.

Size of Micelles Determined by Static Fluorescence Quenching

We developed a new method to measure the average aggregation number of large rod-like micelles using static fluorescence self-quenching of a solubilized fluorophore. The method is based on the increase of self-quenching of micelle-solubilized pyrene through excimer formation. We consider the effect of random distribution of pyrene in micelles and the micellar size distribution. The measured average aggregation M is based on a new M-weighted raging similar to our exponential-weighted averaging in the transient decay method. We apply this method to study the effect of a large concentration of salt on the average aggregation behavior of sodium dodecyl sulfate (SDS) and cetyle tetraammonium bromide (CTAB). The sizes increase with increasing ionic concentrations. For SDS, we used the thermodynamic model developed by Missel et al. to calculate M which we compare with experimental results.

Particle size effects in X-ray absorption analysis: General equation for transmitted intensity

An equation has been derived to describe the dependence of transmitted X-ray intensity on particle size in heterogeneous specimens containing r-types of grains. The equation includes the effect of random distribution of grains in any volume element of the sample, a problem not covered in earlier theoretical work.