297 research outputs found
Dilemmas of Structural Adjustment and Environmental Policies under Instability
Cataloged from PDF version of article.The Turkish structural adjustment since 1980 has been associated with chronic instability. Since the late 1980s, the weaknesses in the fiscal system and the premature external liberalization emerge as the main factors hindering the passage toward stable growth. Enforced and erratic distributional changes and relative stagnation of capital accumulation have undermined the growth potential of the economy. Further, it is demonstrated that existing market structures may negate environmental policies based on market incentives. These observations, as well as those on the interactions of the market system and the environment, create strong arguments in favor of an active state
Turkey, 1980-2000: Financial Liberalization, Macroeconomic (In)Stability, and Patterns of Distribution
This chapter examines the facts and processes characterizing the dynamic macroeconomic adjustments in Turkey since the start of its reforms toward global integration. The study is organized as follows. Section 2 focuses on the analytics of macro adjustments of the two distinct (i.e., 1980-1988/1989 and 1989-2000) phases of liberalization. Section 3 quantifies the macro adjustments via a set of decomposition exercises and traces the evolution of real output and sources of aggregate demand. Microlevel adjustments and related decomposition exercises, in turn, are investigated in Section 4 for the manufacturing sector. The distributional effects of liberalization of commodity trade and finance are summarized in Section 5, and Section 6 gives a conclusion. © Oxford University Press, 2013
Longitudinal Structure Functions in Decaying and Forced Turbulence
In order to reliably compute the longitudinal structure functions in decaying
and forced turbulence, local isotropy is examined with the aid of the isotropic
expression of the incompressible conditions for the second and third order
structure functions. Furthermore, the Karman-Howarth-Kolmogorov relation is
investigated to examine the effects of external forcing and temporally
decreasing of the second order structure function. On the basis of these
investigations, the scaling range and exponents of the longitudinal
structure functions are determined for decaying and forced turbulence with the
aid of the extended-self-similarity (ESS) method. We find that 's are
smaller, for , in decaying turbulence than in forced turbulence. The
reasons for this discrepancy are discussed. Analysis of the local slopes of the
structure functions is used to justify the ESS method.Comment: 15 pages, 16 figure
Magnetars in the Metagalaxy: An Origin for Ultra High Energy Cosmic Rays in the Nearby Universe
I show that the relativistic winds of newly born magnetars with khz initial
spin rates, occurring in all normal galaxies, can accelerate ultrarelativistic
light ions with an E^{-1} injection spectrum, steepening to E^{-2} at higher
energies, with an upper cutoff above 10^{21} eV. Interactions with the CMB
yield a spectrum in good accord with the observed spectrum of Ultra-High Energy
Cosmic Rays (UHECR), if ~ 5-10% of the magnetars are born with voltages
sufficiently high to accelerate the UHECR. The form the spectrum spectrum takes
depends on the gravitational wave losses during the magnetars' early spindown -
pure electromagnetic spindown yields a flattening of the E^3 J(E) spectrum
below 10^{20} eV, while a moderate GZK ``cutoff'' appears if gravitational wave
losses are strong enough. I outline the physics such that the high energy
particles escape with small energy losses from a magnetar's natal supernova,
including Rayleigh-Taylor ``shredding'' of the supernova envelope, expansion of
a relativistic blast wave into the interstellar medium, acceleration of the UHE
ions through surf-riding in the electromgnetic fields of the wind, and escape
of the UHE ions in the rotational equator with negligible radiation loss. The
abundance of interstellar supershells and unusually large supernova remnants
suggests that most of the initial spindown energy is radiated in khz
gravitational waves for several hours after each supernova, with effective
strains from sources at typical distances ~ 3 x 10^{-21}. Such bursts of
gravitational radiation should correlate with bursts of ultra-high energy
particles. The Auger experiment should see such bursts every few years.Comment: 49 pages, 2 Figures, LaTeX (aastex, epsfig, graphicx, float), to be
published June 1, 2003 in the ApJ. Corrected discussion of electromagnetic
surf-riding as the acceleration mechanism and more typos, and reference
Statistics of Dissipation and Enstrophy Induced by a Set of Burgers Vortices
Dissipation and enstropy statistics are calculated for an ensemble of
modified Burgers vortices in equilibrium under uniform straining. Different
best-fit, finite-range scaling exponents are found for locally-averaged
dissipation and enstrophy, in agreement with existing numerical simulations and
experiments. However, the ratios of dissipation and enstropy moments supported
by axisymmetric vortices of any profile are finite. Therefore the asymptotic
scaling exponents for dissipation and enstrophy induced by such vortices are
equal in the limit of infinite Reynolds number.Comment: Revtex (4 pages) with 4 postscript figures included via psfi
Dynamics of vortex tangle without mutual friction in superfluid He
A recent experiment has shown that a tangle of quantized vortices in
superfluid He decayed even at mK temperatures where the normal fluid was
negligible and no mutual friction worked. Motivated by this experiment, this
work studies numerically the dynamics of the vortex tangle without the mutual
friction, thus showing that a self-similar cascade process, whereby large
vortex loops break up to smaller ones, proceeds in the vortex tangle and is
closely related with its free decay. This cascade process which may be covered
with the mutual friction at higher temperatures is just the one at zero
temperature Feynman proposed long ago. The full Biot-Savart calculation is made
for dilute vortices, while the localized induction approximation is used for a
dense tangle. The former finds the elementary scenario: the reconnection of the
vortices excites vortex waves along them and makes them kinked, which could be
suppressed if the mutual friction worked. The kinked parts reconnect with the
vortex they belong to, dividing into small loops. The latter simulation under
the localized induction approximation shows that such cascade process actually
proceeds self-similarly in a dense tangle and continues to make small vortices.
Considering that the vortices of the interatomic size no longer keep the
picture of vortex, the cascade process leads to the decay of the vortex line
density. The presence of the cascade process is supported also by investigating
the classification of the reconnection type and the size distribution of
vortices. The decay of the vortex line density is consistent with the solution
of the Vinen's equation which was originally derived on the basis of the idea
of homogeneous turbulence with the cascade process. The obtained result is
compared with the recent Vinen's theory.Comment: 16 pages, 16 figures, submitted to PR
Finite time singularities in a class of hydrodynamic models
Models of inviscid incompressible fluid are considered, with the kinetic
energy (i.e., the Lagrangian functional) taking the form in 3D Fourier representation, where
is a constant, . Unlike the case (the usual Eulerian
hydrodynamics), a finite value of results in a finite energy for a
singular, frozen-in vortex filament. This property allows us to study the
dynamics of such filaments without the necessity of a regularization procedure
for short length scales. The linear analysis of small symmetrical deviations
from a stationary solution is performed for a pair of anti-parallel vortex
filaments and an analog of the Crow instability is found at small wave-numbers.
A local approximate Hamiltonian is obtained for the nonlinear long-scale
dynamics of this system. Self-similar solutions of the corresponding equations
are found analytically. They describe the formation of a finite time
singularity, with all length scales decreasing like ,
where is the singularity time.Comment: LaTeX, 17 pages, 3 eps figures. This version is close to the journal
pape
Determination of absolute neutrino masses from Z-bursts
Ultrahigh energy neutrinos (UHE\nu) scatter on relic neutrinos (R\nu)
producing Z bosons, which can decay hadronically producing protons (Z-burst).
We compare the predicted proton spectrum with the observed ultrahigh energy
cosmic ray (UHECR) spectrum and determine the mass of the heaviest R\nu via a
maximum likelihood analysis. Our prediction depends on the origin of the
power-like part of the UHECR spectrum: m_\nu=2.75^{+1.28}_{-0.97} eV for
Galactic halo and 0.26^{+0.20}_{-0.14} eV for extragalactic (EG) origin. The
necessary UHE\nu flux should be detected in the near future.Comment: slight rewording, revised neutrino fluxes, conclusions unchanged,
version to appear in Phys. Rev. Let
Grand Unification Signal from Ultra High Energy Cosmic Rays?
The spectrum of ultrahigh energy (above \approx 10^{9} GeV) cosmic rays is
consistent with the decay of GUT scale particles. The predicted mass is
m_X=10^b GeV, where b=14.6_{-1.7}^{+1.6}.Comment: 4 pages, 3 figures one figure removed, one table added, conclusions
essentially remained the same within errorbar
Ultra-High Energy Cosmic Rays, Superheavy Long-Living Particles, and Matter Creation after Inflation
The highest energy cosmic rays, above the Greisen-Zatsepin-Kuzmin cut-off of
cosmic ray spectrum, may be produced in decays of superheavy long-living
X-particles. We conjecture that these particles may be produced naturally in
the early Universe from vacuum fluctuations during inflation and may constitute
a considerable fraction of Cold Dark Matter. We predict a new cut-off in the
UHE cosmic ray spectrum E_{cut-off} < m_inflaton \approx 10^{13} GeV, the exact
position of the cut-off and the shape of the cosmic ray spectrum beyond the GZK
cut-off being determined by the QCD quark/gluon fragmentation. The Pierre Auger
Project installation might discover this phenomenon.Comment: LaTeX, 8 page
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