6,608 research outputs found
Can Performance of Indigenous Factors Influence Growth and Globalisation?"
This paper employs a total of thirty four openness factors and indigenous factors to construct two indicators for 62 world economies for the period 1998-2002. While most globalization studies concentrated on openness factors, regression estimates and simulation studies show that sound performance in indigenous factors are crucial to an economy’s growth and globalization. Empirical evidence shows that an optimal performance in indigenous factors can be identified, and that successful globalized economies are equipped with strong performance in their indigenous factors.Globalization; indigenous factors; openess; world economies
A New Exponential Gravity
We propose a new exponential f(R) gravity model with f(R)=(R-\lambda
c)e^{\lambda(c/R)^n} and n>3, \lambda\geq 1, c>0 to explain late-time
acceleration of the universe. At the high curvature region, the model behaves
like the \LambdaCDM model. In the asymptotic future, it reaches a stable
de-Sitter spacetime. It is a cosmologically viable model and can evade the
local gravity constraints easily. This model share many features with other
f(R) dark energy models like Hu-Sawicki model and Exponential gravity model. In
it the dark energy equation of state is of an oscillating form and can cross
phantom divide line \omega_{de}=-1. In particular, in the parameter range 3<
n\leq 4, \lambda \sim 1, the model is most distinguishable from other models.
For instance, when n=4, \lambda=1, the dark energy equation of state will cross
-1 in the earlier future and has a stronger oscillating form than the other
models, the dark energy density in asymptotical future is smaller than the one
in the high curvature region. This new model can evade the local gravity tests
easily when n>3 and \lambda>1.Comment: 12 pages, 8 figure
Polydimethylsiloxane (PDMS)-based microfluidic channel with integrated commercial pressure sensors
The precise characterisation of boiling in microchannels is essential for the optimisation of applications requiring two phase cooling. In this paper polydimethylsiloxane (PDMS) is employed to make microchannels for characterising microboiling. In particular the material properties of PDMS facilitate rapid prototyping and its optical transparency provides the capability to directly view any fluid flow. The production of microchannels is complicated by the need to integrate custom made sensors. This paper presents a PDMS microfluidic device with integrated commercial pressure sensors, which have been used to perform a detailed characterisation of microboiling phenomena. The proposed approach of integrating commercial pressure sensors into the channel also has potential applications in a range of other microsystems
Excitation Functions of Stopping Power and Flow in Relativistic Heavy-Ion Collisions
Using a relativistic transport (ART) model, we study the stopping power, the
formation of superdense hadronic matter as well as the strength of transverse
and radial flow in central Au+Au collisions at beam momentum from 2 to 12 GeV/c
per nucleon. We find that complete stopping is achieved in the whole beam
momentum range. In particular, the proton rapidity distribution scaled by the
beam rapidity is independent of the beam momentum, and this is in agreement
with the experimental findings. Also, a large volume of superdense hadronic
matter with a local energy density exceeding that expected for the transition
of a hadronic matter to the quark-gluon plasma is formed in collisions at beam
momenta greater than 8 GeV/c per nucleon. Furthermore, it is found that the
transverse flow in these collisions is sensitive to the nuclear equation of
state and decreases with increasing beam momentum. On the other hand, the
radial flow is insensitive to the equation of state, and its strength increases
with beam momentum.Comment: Talk given at NN97, Gatlinburg, Tennessee June 2-6,1997. To appear in
the proc. in Nucl. Phys.
Uranium on uranium collisions at relativistic energies
Deformation and orientation effects on compression, elliptic flow and
particle production in uranium on uranium collisions (UU) at relativistic
energies are studied within the transport model ART. The density compression in
tip-tip UU collisions is found to be about 30% higher and lasts approximately
50% longer than in body-body or spherical UU reactions. The body-body UU
collisions have the unique feature that the nucleon elliptic flow is the
highest in the most central collisions and remain a constant throughout the
reaction. We point out that the tip-tip UU collisions are more probable to
create the QGP at AGS and SPS energies while the body-body UU collisions are
more useful for studying properties of the QGP at higher energies.Comment: 8 pages + 4 figure
Enhancement of low- kaons in AGS heavy-ion collisions
In the relativistic transport model, we show that the recently observed
enhancement of low- kaons ( and ) in Si+Pb collisions at AGS can
be explained if a density isomer is introduced in the nuclear
equation-of-state.Comment: 12 pages, RevTex, 6 figs on request to [email protected]
Thermal Hall conductivity of marginal Fermi liquids subject to out-of plane impurities in high- cuprates
The effect of out-of-plane impurities on the thermal Hall conductivity
of in-plane marginal-Fermi-liquid (MFL) quasiparticles in
high- cuprates is examined by following the work on electrical Hall
conductivity by Varma and Abraham [Phys. Rev. Lett. 86, 4652
(2001)]. It is shown that the effective Lorentz force exerted by these
impurities is a weak function of energies of the MFL quasiparticles, resulting
in nearly the same temperature dependence of and ,
indicative of obedience of the Wiedemann-Franz law. The inconsistency of the
theoretical result with the experimental one is speculated to be the
consequence of the different amounts of out-of-plane impurities in the two
YBaCuO samples used for the and measurements.Comment: 5 pages, 2 eps figures; final versio
Electromagnetic probes of dense matter in heavy-ion collisions
Dilepton and photon production in heavy-ion collisions at SPS energies are
studied in the relativistic transport model that incorporates self-consistently
the change of hadron masses in dense matter. It is found that the dilepton
spectra in proton-nucleus reactions can be well described by the conventional
mechanism of Dalitz decay and direct vector meson decay. However, to provide a
quantitative explanation of the observed dilepton spectra in central heavy-ion
collisions requires contributions other than these direct decays and also
various medium effects. Introducing a decrease of vector meson masses in hot
dense medium, we find that these heavy-ion data can be satisfactorily
explained. Furthermore, the single photon spectra in our calculations with
either free or in-medium meson masses do not exceed the upper bound deduced
from the experiments by the WA80 Collaboration.Comment: 8 pages, including 4 postscript figures. Talk presented at Sixth
International Conference on Nucleus-Nucleus Collisions (NN97), Gatlinburg,
June, 1997, to appear in the proceeding
Enhancement of low-mass dileptons in heavy-ion collisions
Using a relativistic transport model for the expansion stage of S+Au
collisions at 200 GeV/nucleon, we show that the recently observed enhancement
of low-mass dileptons by the CERES collaboration can be explained by the
decrease of vector meson masses in hot and dense hadronic matter.Comment: 12 pages, RevTeX, 3 figures available from [email protected]
Antiflow of kaons in relativistic heavy ion collisions
We compare relativistic transport model calculations to recent data on the
sideward flow of neutral strange K^0_s mesons for Au+Au collisions at 6 AGeV. A
soft nuclear equation of state is found to describe very well the positive
proton flow data measured in the same experiment. In the absence of kaon
potential, the K^0 flow pattern is similar to that of protons. The kaon flow
becomes negative if a repulsive kaon potential determined from the impulse
approximation is introduced. However, this potential underestimates the data
which exhibits larger antiflow. An excellent agreement with the data is
obtained when a relativistic scalar-vector kaon potential, that has stronger
density dependence, is used. We further find that the transverse momentum
dependence of directed and elliptic flow is quite sensitive to the kaon
potential in dense matter.Comment: 5 pages, Revtex, 4 figure
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