2,391 research outputs found
Introduction
The costs and benefits of European Imperialism from the conquest of Ceuta, 1415, to the Treaty of Lusaka, 1974.Twelfth International Economic History Congress. Madrid, 1998.Patrick K. O'Brien and Leandro Prados de la Escosura (eds.)Editada en la Fundación Empresa PúblicaPatrick K. O'Brien and Leandro Prados de la Escosura. The Costs and Benefits for Europeans from their Empires Overseas.Publicad
Extensive Characterization of Seismic Laws in Acoustic Emissions of Crumpled Plastic Sheets
Statistical similarities between earthquakes and other systems that emit
cracking noises have been explored in diverse contexts, ranging from materials
science to financial and social systems. Such analogies give promise of a
unified and universal theory for describing the complex responses of those
systems. There are, however, very few attempts to simultaneously characterize
the most fundamental seismic laws in such systems. Here we present a complete
description of the Gutenberg-Richter law, the recurrence times, Omori's law,
the productivity law, and Bath's law for the acoustic emissions that happen in
the relaxation process of uncrumpling thin plastic sheets. Our results show
that these laws also appear in this phenomenon, but (for most cases) with
different parameters from those reported for earthquakes and fracture
experiments. This study thus contributes to elucidate the parallel between
seismic laws and cracking noises in uncrumpling processes, revealing striking
qualitative similarities but also showing that these processes display unique
features.Comment: Accepted for publication in EP
Measuring Multipartite Concurrence with a Single Factorizable Observable
We show that, for any composite system with an arbitrary number of
finite-dimensional subsystems, it is possible to directly measure the
multipartite concurrence of pure states by detecting only one single
factorizable observable, provided that two copies of the composite state are
available. This result can be immediately put into practice in trapped-ion and
entangled-photon experiments.Comment: 4 pages; no figures; published versio
Three-particle templates for boosted Higgs
We explore the ability of three-particle templates to distinguish color
neutral objects from QCD background. This method is particularly useful to
identify the standard model Higgs, as well as other massive neutral particles.
Simple cut-based analysis in the overlap distributions of the signal and
background is shown to provide a significant rejection power. By combining with
other discriminating variables, such as planar flow, and several variables that
depend on the partonic template, three-particle templates are used to
characterize the influence of gluon emission and color flow in collider events.
The performance of the method is discussed for the case of a highly boosted
Higgs in association with a leptonically-decaying W boson.Comment: 32 pages, 13 figures. v2: Acknowledgments added, typos fixed. v3:
added comparison to filtering method, minor correction and acknowledgment
added. The version to appear in Phys. Rev.
Balance sheets for the acquisition, retention and loss of european empires overseas
This paper is an attempt to assessing the costs and benefits for Europeans from their empires overseas over five centuries, in particular, the net economic gains from empire over the long 19th century when mercantilism was replaced by free trade and over the period of reintegration and de-colonisation brought by the two World Wars. Paradoxically while empires were
growing, empires were at best economically irrelevant for European long run growth in a free trade world. The post-1914 era shows that the benefits from imperial trading blocs were suboptimal solutions compared to open international trade
Electroweak precision constraints on the Lee-Wick Standard Model
We perform an analysis of the electroweak precision observables in the
Lee-Wick Standard Model. The most stringent restrictions come from the S and T
parameters that receive important tree level and one loop contributions. In
general the model predicts a large positive S and a negative T. To reproduce
the electroweak data, if all the Lee-Wick masses are of the same order, the
Lee-Wick scale is of order 5 TeV. We show that it is possible to find some
regions in the parameter space with a fermionic state as light as 2.4-3.5 TeV,
at the price of rising all the other masses to be larger than 5-8 TeV. To
obtain a light Higgs with such heavy resonances a fine-tuning of order a few
per cent, at least, is needed. We also propose a simple extension of the model
including a fourth generation of Standard Model fermions with their Lee-Wick
partners. We show that in this case it is possible to pass the electroweak
constraints with Lee-Wick fermionic masses of order 0.4-1.5 TeV and Lee-Wick
gauge masses of order 3 TeV.Comment: 24 pages, 7 figure
Microstructured blood vessel surrogates reveal structural tropism of motile malaria parasites
Plasmodium sporozoites, the highly motile forms of the malaria parasite, are transmitted naturally by mosquitoes and traverse the skin to find, associate with, and enter blood capillaries. Research aimed at understanding how sporozoites select blood vessels is hampered by the lack of a suitable experimental system. Arrays of uniform cylindrical pillars can be used to study small cells moving in controlled environments. Here, an array system displaying a variety of pillars with different diameters and shapes is developed in order to investigate how Plasmodium sporozoites associate to the pillars as blood vessel surrogates. Investigating the association of sporozoites to pillars in arrays displaying pillars of different diameters reveals that the crescent-shaped parasites prefer to associate with and migrate around pillars with a similar curvature. This suggests that after transmission by a mosquito, malaria parasites may use a structural tropism to recognize blood capillaries in the dermis in order to gain access to the blood stream
Sugestão de adubação fosfatada do algodoeiro para o Estado de Goiás
bitstream/CNPA/18269/1/COMTEC271.pd
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Simultaneous Measurement of Strain and Temperature Using a Single Emission Line
In this study, we present and demonstrate a novel sensor system for simultaneous measurement of strain and temperature through a unique combination of a long period grating and a fiber laser based on a fiber Bragg grating. In order to achieve this, a new erbium-doped fiber laser structure is created, showing an optical signal-to-noise ratio of 55 dB and a peak power measured on the optical spectrum analyzer between -5 and 0 dBm. The strain and the temperature information can be obtained by using a unique emission line through monitoring both the fiber laser wavelength shift and the change of the power level, both of which showing a clear linear behavior
Asteroseismological constraints on the pulsating planetary nebula nucleus (PG 1159-type) RX J2117.1+3412
Aims. We present asteroseismological inferences on RX J2117.1+3412, the hottest known pulsating PG 1159 star. Our results are based on full PG 1159 evolutionary models recently presented by Miller Bertolami & Althaus (2006).
Methods. We performed extensive computations of adiabatic g-mode pulsation periods on PG 1159 evolutionary models with stellar masses ranging from 0.530 to 0.741 M⊙. PG 1159 stellar models are extracted from the complete evolution of progenitor stars started from the ZAMS, through the thermally pulsing AGB and born-again phases to the domain of the PG 1159 stars. We constrained the stellar mass of RX J2117.1+3412 by comparing the observed period spacing with the asymptotic period spacing and with the average of the computed period spacings. We also employed the individual observed periods to find a representative seismological model for RX J2117.1+3412.
Results. We derive a stellar mass M* ∼ 0.56-0.57 M⊙ from the period spacing data alone. In addition, we found a best-fit model representative for RX J2117.1+3412 with an effective temperature Teff = 163 400 K, a stellar mass M* = 0.565 M⊙, and a surface gravity log g = 6.61. The derived stellar luminosity and radius are log (L*/L ⊙) = 3.36 and log (R*/R⊙) = -1.23, respectively, and the He-rich envelope thickness is Menv = 0.02 M⊙. We derive a seismic distance d ∼ 452 pc and a linear size of the planetary nebula DPN ∼ 1.72 pc. These inferences seem to solve the discrepancy between the RX J2117.1+3412 evolutionary timescale and the size of the nebula. All of the seismological tools we use concur to the conclusion that RX J2117.1+3412 must have a stellar mass M* ∼ 0.565 M⊙, much in agreement with recent asteroseismology studies and in clear conflict with the predictions of spectroscopy plus evolutionary tracks.Este documento tiene una corrección (ver documento relacionado).Facultad de Ciencias Astronómicas y GeofísicasInstituto de Astrofísica de La Plat
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