1,650 research outputs found
Viscosity scaling of fingering instability in finite slices with Korteweg stress
We perform linear stability analyses (LSA) and direct numerical simulations
(DNS) to investigate the influence of the dynamic viscosity on viscous
fingering (VF) instability in miscible slices. Selecting the characteristic
scales appropriately the importance of the magnitude of the dynamic viscosity
of individual fluids on VF in miscible slice has been shown in the context of
the transient interfacial tension. Further, we have confirmed this result for
immiscible fluids and manifest the similarities between VF in immiscible and
miscible slices with transient interfacial tension. In a more general setting,
the findings of this letter will be very useful for multiphase viscous flow, in
which the momentum balance equation contains an additional stress term free
from the dynamic viscosity.Comment: 16 pages, 8 figure
Structure and optical properties of Cd substituted ZnO (Zn1-xCdxO) nanostructures synthesized by high pressure solution route
We report synthesis of Cd substituted ZnO nanostructures (Zn1-xCdxO with x
upto \approx .09) by high pressure solution growth method. The synthesized
nanostructures comprise of nanocrystals that are both particles (~ 10-15 nm)
and rods which grow along (002) direction as established by Transmission
electron microscope (TEM) and X-ray diffraction (XRD) analysis. Rietveld
analysis of the XRD data shows monotonous increase of the unit cell volume with
the increase of Cd concentration. The optical absorption as well as the
photoluminescence (PL) shows red shift on Cd substitution. The line width of
the PL spectrum is related to the strain inhomogenity and it peaks in the
region where the CdO phase separates from the Zn1-xCdxO nanostructures. The
time resolved photoemission showed a long lived (~10ns) component. We propose
that the PL behavior of the Zn1-xCdxO is dominated by strain in the sample with
the redshift of the PL linked to the expansion of the unit cell volume on Cd
substitution
Finite Size Effect from Classical Strings in deformed AdS S
We study the finite size effect of rigidly rotating and spinning folded
strings in background. We calculate the leading
order exponential corrections to the infinite size dispersion relation of the
giant magnon, and single spike solutions. For the spinning folded strings we
write the finite size effect in terms of the known Lambert -function.Comment: to appear in JHE
- …