Optical Properties of Metal Wire Array Composites

1996 ◽  
Vol 457 ◽  
Author(s):  
Laura Luo ◽  
T. E. Huber
Keyword(s):  
Volume Fraction ◽  
Wire Array ◽  
Electrically Conducting ◽  
Microchannel Plates ◽  
Transparent Dielectric ◽  
Effective Medium Theories ◽  
Measured Absorption ◽  
The Wire ◽  
High Pressure Injection ◽  
Metal Wires

ABSTRACTAccording to effective medium theories, electrically conducting composites consisting of parallel metal wires embedded in a transparent dielectric can propagate light in the direction of the wire length. We have prepared densely packed arrays (76% volume fraction) of 10-μm diameter indium wires by high pressure injection of glass microchannel plates. For wavelengths longer than 100 μm (k<100 cm−1) the absorption of the wire array is almost three orders of magnitude smaller than that of an indium foil of equal thickness. The measured absorption increases as k0.45±0.07 and can be accounted for by including magnetic dipole effects.

Processing and Characterization of High-conductance Bismuth Wire Array Composites

2000 ◽  
Vol 15 (8) ◽  
pp. 1816-1821 ◽  
Author(s):  
T. E. Huber ◽  
M. J. Graf ◽  
C. A. Foss ◽  
P. Constant
Keyword(s):  
Volume Fraction ◽  
Wire Array ◽  
Nanowire Array ◽  
Trigonal Axis ◽  
Copper Electrodes ◽  
Bi Nanowire ◽  
The Individual ◽  
Anodic Alumina Templates ◽  
High Pressure Injection

We fabricated Bi nanowire array composites with wire diameters from 30 to 200 nm by high-pressure injection (HPI) of Bi melt into porous anodic alumina templates. The composites were dense, with Bi volume fraction in excess of 50%. The parallel Bi nanowires, whose length appeared to be limited only by the thickness of the host template (up to 55 μm), terminated at both sides of the composite in the Bi bulk. The individual Bi nanowire crystal structure was rhombohedral, with the same lattice parameters as that of bulk Bi; the wires in the array were predominantly oriented with the trigonal axis along the wire length. Low contact resistance was achieved by bonding the composite to copper electrodes.

Bioconvection of a Radiating Hybrid Nanofluid Past a Thin Needle in the Presence of Heterogeneous-Homogeneous Chemical Reaction

2021 ◽  
Author(s):  
V Puneeth ◽  
S. Manjunatha ◽  
O.D Makinde ◽  
B.J Gireesha
Keyword(s):  
Differential Equations ◽  
Volume Fraction ◽  
Heterogeneous Reaction ◽  
Hybrid Nanofluid ◽  
Homogeneous Reaction ◽  
Reaction Parameter ◽  
Bulk Fluid ◽  
Electrically Conducting ◽  
Footwear Industry ◽  
Ultraviolet Illumination

Abstract : The photo catalytic nature of TiO_2 finds applications in medicinal field to kill cancer cells, bacteria and viruses under mild ultraviolet illumination and the antibacterial characteristic of Ag makes the composition Ag-TiO_2 applicable for various purposes. It can also be used in other engineering appliances and industries such as humidity sensor, coolants and in footwear industry. Hence, this study deals with the analysis of the effects of Magnetic field, thermal radiation and quartic autocatalysis of heterogeneous-homogeneous reaction in an electrically conducting Ag-TiO_2-H_2 O hybrid nanofluid. Furthermore, the gyrotactic microorganisms are used as active mixers to prevent agglomeration and sedimentation of TiO_2 that occurs due to its hydrophobic nature. The Mathematical model takes the form of partial differential equations with viscosity and thermal conductivity being the functions of volume fraction. These equations are converted to ordinary differential equations by using similarity transformation and are solved by RKF-45 method with the aid of shooting method. It is observed that the increase in the size of the needle enhances the overall performance of the hybrid nanofluid. Furthermore, the temperature of the hybrid nanofluid increases with the increase in volume fraction. It is observed that the friction produced by the Lorentz force increases the temperature of the nanofluid. It is further observed that the heterogeneous reaction parameter has more significant effect on the concentration of bulk fluid than the homogeneous reaction parameter.

scholarly journals Chebyshev collocation computation of magneto-bioconvection nanofluid flow over a wedge with multiple slips and magnetic induction

2018 ◽  
Vol 232 (4) ◽  
pp. 109-122 ◽  
Author(s):  
MJ Uddin ◽  
MN Kabir ◽  
O Anwar Bég ◽  
Y Alginahi
Keyword(s):  
Magnetic Induction ◽  
Volume Fraction ◽  
Nanofluid Flow ◽  
Local Skin ◽  
Chebyshev Collocation ◽  
Electrically Conducting ◽  
Similarity Transformations ◽  
Local Skin Friction ◽  
Multiple Slips ◽  
Local Sherwood Number

In this article, the steady two-dimensional stagnation point flow of a viscous incompressible electrically conducting bio-nanofluid over a stretching/shrinking wedge in the presence of passively control boundary condition, Stefan blowing and multiple slips is numerically investigated. Magnetic induction is also taken into account. The governing conservation equations are rendered into a system of ordinary differential equations via appropriate similarity transformations. The reduced system is solved using a fast, convergent Chebyshev collocation method. The influence of selected parameters on the dimensionless velocity, induced magnetic field, temperature, nanoparticle volume fraction and density of motile microorganisms as well as on the local skin friction, local Nusselt number, local Sherwood number and density of motile microorganism numbers is discussed and presented graphically. Validation with previously published results is performed and an excellent agreement is found. The study is relevant to electromagnetic manufacturing processes involving bio-nanofluids.

scholarly journals Numerical investigation of MHD stagnation-point flow and heat transfer of sodium alginate non-Newtonian nanofluid

2019 ◽  
Vol 8 (1) ◽  
pp. 179-192 ◽  
Author(s):  
Bhuvnesh Sharma ◽  
Sunil Kumar ◽  
M.K. Paswan
Keyword(s):  
Differential Equations ◽  
Mixed Convection ◽  
Sodium Alginate ◽  
Volume Fraction ◽  
Skin Friction Coefficient ◽  
Electrically Conducting ◽  
Flow And Heat Transfer ◽  
Analytical Approximations ◽  
Temperature Distributions ◽  
Homotopy Analysis

Abstract A rigorous analysis of unsteady magnetohydrodynamic mixed convection and electrically conducting nanofluid model with a stretching/shrinking wedge is presented. First, the governing partial differential equations for momentum and energy conservation are converted to coupled nonlinear ordinary differential equations by means of exact similarity transformation. The homotopy analysis method (HAM) is employed to obtain the analytical approximations for flow velocity and temperature distributions of alumina-sodium alginate naofluid. The solution is found to be dependent on some parameters including the nanoparticle volume fraction, unsteadiness parameter, magnetic parameter, mixed convection parameter and the generalized prandtl number. A systematic study is carried out to illustrate the effects of these parameters on the velocity and temperature distributions. Also, the value of skin friction coefficient and local Nusselt number are compared with copper-sodium alginate and titania-sodium alginate nanofluids.

On a Spring-Network Model and Effective Elastic Moduli of Granular Materials

1999 ◽  
Vol 66 (1) ◽  
pp. 172-180 ◽  
Author(s):  
K. Alzebdeh ◽  
M. Ostoja-Starzewaski
Keyword(s):  
Granular Materials ◽  
Disordered Systems ◽  
Granular Media ◽  
Elastic Moduli ◽  
Volume Fraction ◽  
Effective Medium ◽  
Solid State Physics ◽  
Two Phase ◽  
Effective Medium Theories ◽  
The Individual

Two challenges in mechanics of granular media are taken up in this paper: (i) development of adequate numerical discrete element models of topologically disordered granular assemblies, and (ii) calculation of macroscopic elastic moduli of such materials using effective medium theories. Consideration of the first one leads to an adaptation of a spring-network (Kirkwood) model of solid-state physics to disordered systems, which is developed in the context of planar Delaunay networks. The model employs two linear springs: a normal one along an edge connecting two neighboring vertices (grain centers) which accounts for normal interactions between the grains, as well as an angular one which accounts for angle changes between two edges incident onto the same vertex; edges remain straight and grain rotations do not appear. This model is then used to predict elastic moduli of two-phase granular materials—random mixtures of soft and stiff grains —for high coordination numbers. It is found here that an effective Poisson’s ratio, νeff, of such a mixture is a convex function of the volume fraction, so that νeff may become negative when the individual Poisson’s ratios of both phases are both positive. Additionally, the usefulness of three effective medium theories—perfect disks, symmetric ellipses, and asymmetric ellipses—is tested.

Concept of the high-energy photon emission from the wire array Z-pinch

2001 ◽  
Author(s):  
P. Kubes ◽  
J. Kravarik ◽  
D. Klir ◽  
Yu. L. Bakshaev ◽  
P. I. Blinov ◽  
...  
Keyword(s):  
Wire Array ◽  
Photon Emission ◽  
High Energy ◽  
High Energy Photon ◽  
Energy Photon ◽  
The Wire ◽  
Z Pinch

Influence of chemically radiative nanoparticles on flow of Maxwell electrically conducting fluid over a convectively heated exponential stretching sheet

2019 ◽  
Vol 16 (6) ◽  
pp. 791-805
Author(s):  
Atul Kumar Ray ◽  
Vasu B.
Keyword(s):  
Stretching Sheet ◽  
Volume Fraction ◽  
Maxwell Fluid ◽  
Nanoparticle Volume Fraction ◽  
Analysis Method ◽  
Content Type ◽  
Electrically Conducting ◽  
Exponential Stretching ◽  
Homotopy Analysis ◽  
Exponential Stretching Sheet

Purpose This paper aims to examine the influence of radiative nanoparticles on incompressible electrically conducting upper convected Maxwell fluid (rate type fluid) flow over a convectively heated exponential stretching sheet with suction/injection in the presence of heat source taking chemical reaction into account. Also, a comparison of the flow behavior of Newtonian and Maxwell fluid containing nanoparticles under the effect of different thermophysical parameters is elaborated. Velocity, temperature and nanoparticle volume fractions are assumed to have exponential distribution at boundary. Buongiorno model is considered for nanofluid transport. Design/methodology/approach The equations, which govern the flow, are reduced to ordinary differential equations using suitable transformation. The transformed equations are solved using a robust homotopy analysis method. The convergence of the homotopy series solution is explicitly discussed. The present results are compared with the results reported in the literature and are found to be in good agreement. Findings It is observed from the present study that larger relaxation time leads to slower recovery, which results in a decrease in velocity, whereas temperature and nanoparticle volume fraction is increased. Maxwell nanofluid has lower velocity with higher temperature and nanoparticle volume fraction when compared with Newtonian counterpart. Also, the presence of magnetic field leads to decrease the velocity of the nanofluid and enhances the skin coefficient friction. The existence of thermal radiation and heat source enhance the temperature. Further, the presence of chemical reaction leads to decrease in nanoparticle volume fraction. Higher value of Deborah number results in lower the rate of heat and mass transfer. Originality/value The novelty of present work lies in understanding the impact of fluid elasticity and radiative nanoparticles on the flow over convectively heated exponentially boundary surface in the presence of a magnetic field using homotopy analysis method. The current results may help in designing electronic and industrial applicants. The present outputs have not been considered elsewhere.

Study of the Compression of a Condensed Deuterated Target Installed on the Wire Array Axis

2019 ◽  
Vol 45 (9) ◽  
pp. 805-820 ◽  
Author(s):  
V. V. Aleksandrov ◽  
G. S. Volkov ◽  
E. V. Grabovski ◽  
A. N. Gritsuk ◽  
I. V. Volobuev ◽  
...  
Keyword(s):  
Wire Array ◽  
The Wire ◽  
Array Axis

scholarly journals The mechanical behaviour of single crystals of mercury

1935 ◽  
Vol 148 (863) ◽  
pp. 120-146 ◽  
Keyword(s):  
Secondary Structure ◽  
Single Crystals ◽  
Pure Metal ◽  
Residual Resistance ◽  
Slip Planes ◽  
Cumulative Process ◽  
The Wire ◽  
Metal Wires ◽  
Structural Imperfections ◽  
Crystallographic Axes

It is a familiar fact, first pointed out by one of the present authors many years ago, that metal wires can be prepared which, when stretched, glide on a number of parallel faces. Such wires are usually spoken of as single crystals of the metal, and X-ray analysis has proved that the directions of the crystallographic axes of the metal are fixed throughout the wire. If, however, the wire consist of atoms arranged on an ideal crystal lattice, there seems no reason why there should be, among a set of crystallographically equivalent glide planes, certain more or less regularly spaced planes of weakness, along which glide takes place. The existence of these slip planes, periodically spaced, may be interpreted as evidence of a periodic secondary structure inherent in the crystal, for the preferential glide is not a cumulative process; that is, the resistance to glide along such planes does not become less as slip progresses, but greater. The phenomenon is, therefore, not due to certain chance planes, among a set of almost identical planes, starting as glide planes and then continuing as such, rather than their neighbours, because of progressive softening, but rather to certain preferred planes being disposed to glide. On the other hand, the phenomenon may be set down as due to a secondary structure not inherent in the crystal, but called into existence by strain, a dislocation of any one crystal plane producing a dislocation of a distant plane by some process of accumulation of small disturbances handed on from plane to plane. A third possibility is that the preferred slip planes would not be found in a lattice of perfectly pure metal, but are due to impurities, which may be either foreign metals or dissolved gases; these maybe supposed to segregate into particular planes and have a weakening effect. In this connection reference may be made to the electrical resistance of metals at low temperatures. Kapitza, in his extended investigations of the effect of a magnetic field on the resistance of metals, attributes the residual resistance of a metal to structural imperfections of the lattice, which he appears to associate with minute impurities. “It is known that in a metal which is not in a perfect crystalline state, and which contains even small traces of impurity, there exists a disturbance which increases the specific resistance.” The residual resistance is well known to decrease with increasing purity, as particularly exemplified by gold and platinum, while for mercury there is no residual resistance. If, therefore, the preferential glide on certain planes is due to impurities, pure mercury should not show it.

Go-water nanofluid inside semi porous channel: analytical investigation

2015 ◽  
Vol 12 (2) ◽  
pp. 103-108 ◽  
Author(s):  
M. Azimi ◽  
R. Riazi
Keyword(s):  
Volume Fraction ◽  
Solid Volume Fraction ◽  
Variational Iteration Method ◽  
Analytical Investigation ◽  
Expansion Ratio ◽  
Velocity Fields ◽  
Porous Channel ◽  
Nanofluid Flow ◽  
Electrically Conducting ◽  
Steady Laminar

This paper concerns the analytical investigation of the GO-water nanofluid flow in a semi-porous channel. The Similarity Berman’s transformation is employed to convert the governing partial differential equations of a steady laminar flow of an electrically conducting fluid in a two dimensional channel. Reconstruction of Variational Iteration Method (RVIM) has been used to obtain the expressions for velocity fields. Graphs are sketched and discussed for various parameters, especially the effect of the expansion ratio on velocity fields. The results indicated that the Reynolds number, Hartmann number and solid volume fraction have strong effect on velocity boundary layer thickness.

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