On the origin of \gamma-ray emission in \eta\ Carina

\eta\ Car is the only colliding-wind binary for which high-energy \gamma\ rays are detected. Although the physical conditions in the shock region change on timescales of hours to days, the variability seen at GeV energies is weak and on significantly longer timescales. The \gamma-ray spectrum exhibits two features that can be interpreted as emission from the shocks on either side of the contact discontinuity. Here we report on the first time-dependent modelling of the non-thermal emission in \eta\ Car. We find that emission from primary electrons is likely not responsible for the \gamma-ray emission, but accelerated protons interacting with the dense wind material can explain the observations. In our model, efficient acceleration is required at both shocks, with the primary side acting as a hadron calorimeter, whilst on the companion side acceleration is limited by the flow time out of the system, resulting in changing acceleration conditions. The system therefore represents a unique laboratory for the exploration of hadronic particle acceleration in non-relativistic shocks.Comment: 5 pages, 4 figures, 1 table, accepted for publication in MNRAS Letter

Redistributive effects of regional transfers: a conceptual framework

This paper presents a conceptual framework to analyse the redistributive impact of transfers in the context of a decentralized economy. The framework is illustrated by means of a numerical example that describes an economy with three regions and two levels of government -the central level and the regional level-. With this set up, the paper analyses a variety of transfer systems and considers its effects on redistribution using as benchmark a centralized version of this economy, in which tax capacity is unevenly distributed across the three regions and central government public expenditure is distributed across regions according to their population

Singular spectrum analysis : a note on data processing for Fourier transform hyperspectral imagers

Hyperspectral remote sensing is experiencing a dazzling proliferation of new sensors, platforms, sys tems, and applications with the introduction of novel, low cost, low weight sensors. Curiously, relatively little development is now occurring in the use of Fourier Transform (FT) systems, which have the potential to operate at extremely high throughput wi thout use of a slit or reductions in both spatial and spectral resolution that thin film based mosaic sensors introduce. This study introduces a new physics - based analytical framework called Singular Spectrum Analysis (SSA) to process raw hyperspectral ima gery collected with FT imagers that addresses some of the data processing issues associated with FT instruments including the need to remove low frequency variations in the interferogram that are introduced by the optical system, as well as high frequency variations that lay outside the detector band pass. Synthetic interferogram data is analyzed using SSA, which adaptively decomposes the original synthetic interferogram into several independent components associated with the signal, photon and system nois e, and the field illumination pattern

José Joaquín de Mora y la divulgación de la doctrina económica liberal en Latinoamérica en los inicios del siglo XIX

José Joaquín de Mora (1783-1864) was a prominent Spanish economist who, during the first half of the nineteenth century, did a remarkable job disseminating the principles of liberalism and free-trade in Spain. He also had a significant presence in Latin America, where he became an outstanding popularizer of political economy, especially in the Republic of Chile. Indeed, this work analyses the articles written by de Mora in El Mercurio de Chile (1828-1829), which were intellectually indebted to classical political economy, in particular, to Smith-Mc-Culloch''s theory of economic growth, and embedded as a whole a complete institutional reform and an economic agenda that promoted the foundation of commercial banks, the introduction of direct taxation, public debt issuing and free trade. These Chilean articles give a new account of de Mora''s work on political economy, showing how he combined common doctrinal background and proposals of reform and policies with a modernized rhetoric over the course of almost three decades. El economista gaditano José Joaquín de Mora (1783-1864), conocido por su empeño en la difusión de los principios del liberalismo y del librecambio en España, desempeñó un destacado papel como popularizador de la economía política en Latinoamérica en general y en la República de Chile en particular. Este trabajo analiza los artículos que publicó en El Mercurio Chileno (1828-1829), los cuales presentan una gran deuda intelectual con los economistas clásicos, en particular con el modelo de crecimiento económico de Smith-McCulloch. Ofrecen también un completo plan de reforma institucional y de política económica que incluía la promoción de bancos de «descuento y circulación», la tributación directa, la emisión de deuda pública y la libertad de comercio en la República de Chile. Además, tales artículos permiten reinterpretar el conjunto de la obra económica de Mora ya que tanto sus contenidos doctrinales como las propuestas de reforma se repetirán, con una retórica modernizada, en sus escritos económicos a lo largo de casi tres décadas

Hyperspectral imaging based detection of PVC during Sellafield repackaging procedures.

Traditionally, Special Nuclear Material (SNM) at Sellafield has been stored in multi-layered packages, consisting of metallic cans and an over-layer of plasticized Polyvinyl Chloride (PVC) as an intermediate layer when transitioning between areas of different radiological classification. However, it has been found that plasticized PVC can break down in the presence of both radiation and heat, releasing hydrochloric acid which can corrode these metallic containers. Therefore, internal repackaging procedures at Sellafield have focused recently on the removal of these PVC films from containers, where as much degraded and often adhered PVC as possible is manually removed based on visual inspection. This manual operation is time-consuming and it is possible that residual fragments of PVC could remain, leading to corrosion-related issues in future. In this work, Hyperspectral Imaging (HSI) was evaluated as a new tool for detecting PVC on metallic surfaces. Samples of stainless steel type 1.4404 – also known as 316L, the same as is used to construct SNM cans – and PVC were imaged in our experiments, and Support Vector Machine (SVM) classification models were used to generate detection maps. In these maps, pixels were classified into either PVC or 316L based on their spectral responses in the range 954-1700nm of the electromagnetic spectrum. Results suggest that HSI could be used for an effective automated detection and quantification of PVC during repackaging procedures, detection and quantification that could be extended to other similar applications