1,673 research outputs found
Off-shoring and productivity growth in the Italian manufacturing industries
We employ input-output tables to study the relation between off-shoring and productivity growth in the Italian manufacturing industries in 1995-2003. Our results indicate that not all types of off-shoring are positively related to productivity growth. In particular, the international outsourcing of intermediates within the same industry (ânarrow off-shoringâ) is beneficial for productivity growth, while the off-shoring of services is not. We also find that the way in which off-shoring is measured may matter considerably. The positive relation between off-shoring of intermediates and productivity growth disappears when our direct measure of off-shoring is replaced with the Feenstra-Hanson measure employed in other studies.International trade, Productivity growth; offshoring; Italian economy
Italyâs decline: getting the facts right
The Italian economy is often said to be on a declining path. In this paper, we document that: (i) Italyâs current decline is a labor productivity problem (ii) the labor productivity slowdown stems from declining productivity growth in all industries but utilities (with manufacturing contributing for about one half of the reduction) and diminished interindustry reallocation of workers from agriculture to market services; (iii) the labor productivity slowdown has been mostly driven by declining TFP, with roughly unchanged capital deepening. The only mild decline of capital deepening is due to the rise in the value added share of capital that counteracted declining capital accumulation.Productivity growth, Productivity slowdown, TFP, decline, Italy
Effective Constraints and Physical Coherent States in Quantum Cosmology: A Numerical Comparison
A cosmological model with a cyclic interpretation is introduced, which is
subject to quantum back-reaction and yet can be treated rather completely by
physical coherent state as well as effective constraint techniques. By this
comparison, the role of quantum back-reaction in quantum cosmology is
unambiguously demonstrated. Also the complementary nature of strengths and
weaknesses of the two procedures is illustrated. Finally, effective constraint
techniques are applied to a more realistic model filled with radiation, where
physical coherent states are not available.Comment: 32 pages, 25 figure
Giant electrocaloric effect around T
We use molecular dynamics with a first-principles-based shell model potential
to study the electrocaloric effect (ECE) in lithium niobate, LiNbO, and
find a giant electrocaloric effect along a line passing through the
ferroelectric transition. With applied electric field, a line of maximum ECE
passes through the zero field ferroelectric transition, continuing along a
Widom line at high temperatures with increasing field, and along the
instability that leads to homogeneous ferroelectric switching below with
an applied field antiparallel to the spontaneous polarization. This line is
defined as the minimum in the inverse capacitance under applied electric field.
We investigate the effects of pressure, temperature and applied electric field
on the ECE. The behavior we observe in LiNbO should generally apply to
ferroelectrics; we therefore suggest that the operating temperature for
refrigeration and energy scavenging applications should be above the
ferroelectric transition region to obtain large electrocaloric response. We
find a relationship among , the Widom line and homogeneous switching that
should be universal among ferroelectrics, relaxors, multiferroics, and the same
behavior should be found under applied magnetic fields in ferromagnets.Comment: 5 page
An exact representation of the fermion dynamics in terms of Poisson processes and its connection with Monte Carlo algorithms
We present a simple derivation of a Feynman-Kac type formula to study
fermionic systems. In this approach the real time or the imaginary time
dynamics is expressed in terms of the evolution of a collection of Poisson
processes. A computer implementation of this formula leads to a family of
algorithms parametrized by the values of the jump rates of the Poisson
processes. From these an optimal algorithm can be chosen which coincides with
the Green Function Monte Carlo method in the limit when the latter becomes
exact.Comment: 4 pages, 1 PostScript figure, REVTe
Origin of Large Dielectric Constant with Large Remnant Polarization and Evidence of Magnetoelectric Coupling in Multiferroic La modified BiFeO3-PbTiO3 Solid Solution
The presence of superlattice reflections and detailed analyses of the powder
neutron and x-ray diffraction data reveal that La rich
(BF-LF)-(PT) (BF-LF-PT) has ferroelectric
rhombohedral crystal structure with space group \textit{} at ambient
conditions. The temperature dependence of lattice parameters, tilt angle,
calculated polarization , volume, and integrated intensity of
superlattice and magnetic reflections show an anomaly around 170 K. Impedance
spectroscopy, dielectric and ac conductivity measurements were performed in
temperature range to probe the origin of large remnant
polarization and frequency dependent broad transitions with large dielectric
constant near . Results of impedance spectroscopy measurements
clearly show contributions of both grain and grain boundaries throughout the
frequency range ( Hz Hz). It could be concluded
that the grain boundaries are more resistive and capacitive as compared to the
grains, resulting in inhomogeneities in the sample causing broad frequency
dependent dielectric anomalies. Enhancement in dielectric constant and remnant
polarization values are possibly due to space charge polarization caused by
piling of charges at the interface of grains and grain boundaries. The
imaginary parts of dielectric constant () Vs frequency
data were fitted using Maxwell-Wagner model at K) and model
fits very well with the data up to Hz. Magnetodielectric measurements
prove that the sample starts exhibiting magnetoelectric coupling at
K, which is also validated by neutron diffraction data.Comment: 20 pages, 10 figure
Self-bound many-body states of quasi-one-dimensional dipolar Fermi gases: Exploiting Bose-Fermi mappings for generalized contact interactions
Using a combination of results from exact mappings and from mean-field theory
we explore the phase diagram of quasi-one-dimensional systems of identical
fermions with attractive dipolar interactions. We demonstrate that at low
density these systems provide a realization of a single-component
one-dimensional Fermi gas with a generalized contact interaction. Using an
exact duality between one-dimensional Fermi and Bose gases, we show that when
the dipole moment is strong enough, bound many-body states exist, and we
calculate the critical coupling strength for the emergence of these states. At
higher densities, the Hartree-Fock approximation is accurate, and by combining
the two approaches we determine the structure of the phase diagram. The
many-body bound states should be accessible in future experiments with
ultracold polar molecules
Fragile phase stability in (1-x)Pb(Mg1/3Nb2/3O3)-xPbTiO3 crystals: A comparisons of [001] and [110] field-cooled phase diagrams
Phase diagrams of [001] and [110] field-cooled (FC)
(1-x)Pb(Mg1/3Nb2/3O3)-xPbTiO3 or PMN-xPT crystals have been constructed, based
on high-resolution x-ray diffraction data. Comparisons reveal several
interesting findings. First, a region of abnormal thermal expansion above the
dielectric maximum was found, whose stability range extended to higher
temperatures by application of electric field (E). Second, the rhombohedral (R)
phase of the ZFC state was replaced by a monoclinic MA in the [001] FC diagram,
but with monoclinic MB in the [110] FC. Third, the monoclinic MC phase in ZFC
and [001] FC diagram was replaced by an orthorhombic (O) phase in the [110] FC.
Finally, in the [001] FC diagram, the phase boundary between tetragonal (T) and
MA was extended to lower PT contents (x=0.25); whereas in the [110] FC diagram,
this extended region was entirely replaced by the O phase. These results
clearly demonstrate that the phase stability of PMN-xPT crystals is quite
fragile, depending not only on modest changes in E, but also on the direction
along which that E is applied.Comment: 13 pages, 8 figures, 1 tabl
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