Quantitative DRIFTS investigation of possible reaction mechanisms for the water-gas shift reaction on high-activity Pt- and Au-based catalysts

The present work emphasizes the importance of including a full quantitative analysis when in situ operando methods are used to investigate reaction mechanisms and reaction intermediates. The fact that some surface species exchange at a similar rate to the reaction product during isotopic transients is a necessary but not sufficient criterion for participation as a key reaction intermediate. This is exemplified here in the case of highly active low-temperature water-gas shift (WGS) catalysts based on gold and platinum. Operando DRIFTS data, isotopic exchanges, and DRIFTS calibration curves relating the concentration of formate species to the corresponding DRIFTS band intensity were combined to obtain a quantitative measure of the specific rate of formate decomposition. Despite displaying a rapid isotopic exchange rate (sometimes as fast as that of the reaction product CO2), the concentration of formates seen by DRIFTS was found to account for at most only 10% of the CO2 produced under the experimental conditions reported herein. These new results obtained on Au/CeZrO4 and Pt/CeO2 preparations (which are among the most active low-temperature WGS catalysts reported to date), led to the same conclusions regarding the minor role of IR-observable formates as those obtained in the case of less active Au/Ce(La)O-2 and Pt/ZrO2 catalysts. (c) 2007 Elsevier Inc. All rights reserved.

On the Sources of Private Information in FX Markets

We investigate the source of information advantage in inter-dealer FX trading using data on trades and counterparty identities. In liquid dollar exchange rates, information is concentrated among dealers that trade most frequently and specialize their activity in a particular rate. In cross-rates, traders that engage in triangular arbitrage are best informed. Better-informed traders are also located on larger trading floors. In cross-rates, the ability to forecast flows explains all of the advantage of the triangular arbitrageurs. In liquid dollar rates, specialist traders can forecast both order flow and the component of exchange rate changes that is uncorrelated with flow.

Determining the Reaeration Coefficient and Hydrodynamic Properties of Rivers Using Inert Gas Tracers

Various contaminants which can be aerobically degraded find their way directly or indirectly into surface water bodies. The reaeration coefficient (K2) characterises the rate at which oxygen can transfer from the atmosphere across the air-water interface following oxygen depletion in a water body. Other mechanisms (like advection, dispersion and transient storage) determine how quickly the contaminants can spread in the water, affecting their spatial and temporal concentrations. Tracer methods involving injection of a gas into the water body have traditionally been used for direct (in-situ) measurement of K2 in a given reach. This paper shows how additional modelling of tracer test results can be used to quantify also hydrodynamic mechanisms (e.g. dispersion and storage exchange coefficients, etc.). Data from three tracer tests conducted in the River Lagan (Northern Ireland) using an inert gas (krypton, Kr) are re-analysed using two solute transport models (ADM, TSM) and an inverse-modelling framework (OTIS-P). Results for K2 are consistent with previously published values for this reach (K2(20)~10-40 d-1). The storage area constituted 30-60% of the main cross-section area and the storage exchange rate was between 2.5×10-3-3.2×10-3s-1. The additional hydrodynamic parameters obtained give insight into transport and dispersion mechanisms within the reach.

Why and how FDI stocks are a biased measure of MNE affiliate activity

Many international business (IB) studies have used foreign direct investment (FDI) stocks to measure the aggregate value-adding activity of multinational enterprises (MNE) affiliates in host countries. We argue that FDI stocks are a biased measure of that activity, because the degree to which they overestimate or underestimate affiliate activity varies systematically with host-country characteristics. First, most FDI into countries that serve as tax havens generate no actual productive activity; thus FDI stocks in such countries overestimate affiliate activity. Second, FDI stocks do not include locally raised external funds, funds widely used in countries with well-developed financial markets or volatile exchange rates, resulting in an underestimation of affiliate activity in such countries. Finally, the extent to which FDI translates into affiliate activity increases with affiliate labor productivity, so in countries where labor is more productive, FDI stocks also result in an underestimation of affiliate activity. We test these hypotheses by first regressing affiliate value-added and affiliate sales on FDI stocks to calculate a country-specific mismatch, and then by regressing this mismatch on a host country's tax haven status, level of financial market development, exchange rate volatility, and affiliate labor productivity. All hypotheses are supported, implying that FDI stocks are a biased measure of MNE affiliate activity, and hence that the results of FDI-data-based studies of such activity need to be reconsidered. [ABSTRACT FROM AUTHOR]

Determinantes da procura da Bitcoin

Dissertação de Mestrado apresentada ao Instituto de Contabilidade e Administração do Porto para a obtenção do grau de Mestre em Contabilidade e Finanças, sob orientação da Professora Doutora Celsa Maria Carvalho Machado

Reporting Income Taxes in the Banking Sector In Angola - Accounting, Tax Regulation and Financial Reporting Evidences

This research provides an insight into income taxes reporting in Angola, based on hand collected data from the annual reports of banks. Empirical studies on Angolan companies are scarce, in part due to the limited access to data. The results show that income taxes’ reporting has improved over the years 2010-2013, becoming more reliable and understandable. The Angolan Government is boosting the economic growth through tax benefits in the investment in public debt, which cause a reduction in the banks’ effective tax rate. The new income tax law will reduce the statutory tax rate from 2015 onwards and change the taxable income, resulting in shifting the focus to promoting private investment.

La géographie du dollar et la Chine : analyse géoéconomique d'une sédition monétaire

L’équilibre économique mondial repose sur une asymétrie structurelle dont les pôles antagonistes principaux sont les États-Unis et l’Asie orientale. À la base de cet axe de tension géographique se trouve la question de la représentation mondiale de la richesse. La domination du dollar permet aux États-Unis un accès disproportionné aux ressources planétaires. Les pays créanciers, dont fait partie la Chine, hésitent à laisser flotter leur monnaie et attaquer l’hégémonie du dollar. Entre temps, les déséquilibres s’intensifient, tout comme les tensions politiques, par l’effet de ce système monétaire qui participe au maintien d’un monde unipolaire. Le système monétaire actuel n’offre aucune perspective endogène quant à la résolution des déséquilibres que son équilibre requiert. Ce mémoire cherche à identifier les stratégies géoéconomiques de la Chine pour se soustraire de l’emprise du dollar.

Liquidity traps, capital flows

This paper explores the role of capital flows and exchange rate dynamics in shaping the global economy's adjustment in a liquidity trap. Using a multi-country model with nominal rigidities, we shed light on the global adjustment since the Great Recession, a period where many advanced economies were pushed to the zero bound on interest rates. We establish three main results: (i) When the North hits the zero bound, downstream capital flows alleviate the recession by reallocating demand to the South and switching expenditure toward North goods. (ii) A free capital flow regime falls short of supporting efficient demand and expenditure reallocations and induces too little downstream (upstream) flows during (after) the liquidity trap. (iii) When it comes to capital flow management, individual countries' incentives to manage their terms of trade conflict with aggregate demand stabilization and global efficiency. This underscores the importance of international policy coordination in liquidity trap episodes.

Computationally Efficient Bootstrap Prediction Intervals for Returns and Volatilities in ARCH and GARCH Processes

We propose a novel, simple, efficient and distribution-free re-sampling technique for developing prediction intervals for returns and volatilities following ARCH/GARCH models. In particular, our key idea is to employ a Box–Jenkins linear representation of an ARCH/GARCH equation and then to adapt a sieve bootstrap procedure to the nonlinear GARCH framework. Our simulation studies indicate that the new re-sampling method provides sharp and well calibrated prediction intervals for both returns and volatilities while reducing computational costs by up to 100 times, compared to other available re-sampling techniques for ARCH/GARCH models. The proposed procedure is illustrated by an application to Yen/U.S. dollar daily exchange rate data.

First-principles electronic theory of non-collinear magnetic order in transition-metal nanowires

The structural, electronic and magnetic properties of one-dimensional 3d transition-metal (TM) monoatomic chains having linear, zigzag and ladder geometries are investigated in the frame-work of first-principles density-functional theory. The stability of long-range magnetic order along the nanowires is determined by computing the corresponding frozen-magnon dispersion relations as a function of the 'spin-wave' vector q. First, we show that the ground-state magnetic orders of V, Mn and Fe linear chains at the equilibrium interatomic distances are non-collinear (NC) spin-density waves (SDWs) with characteristic equilibrium wave vectors q that depend on the composition and interatomic distance. The electronic and magnetic properties of these novel spin-spiral structures are discussed from a local perspective by analyzing the spin-polarized electronic densities of states, the local magnetic moments and the spin-density distributions for representative values q. Second, we investigate the stability of NC spin arrangements in Fe zigzag chains and ladders. We find that the non-collinear SDWs are remarkably stable in the biatomic chains (square ladder), whereas ferromagnetic order (q =0) dominates in zigzag chains (triangular ladders). The different magnetic structures are interpreted in terms of the corresponding effective exchange interactions J(ij) between the local magnetic moments μ(i) and μ(j) at atoms i and j. The effective couplings are derived by fitting a classical Heisenberg model to the ab initio magnon dispersion relations. In addition they are analyzed in the framework of general magnetic phase diagrams having arbitrary first, second, and third nearest-neighbor (NN) interactions J(ij). The effect of external electric fields (EFs) on the stability of NC magnetic order has been quantified for representative monoatomic free-standing and deposited chains. We find that an external EF, which is applied perpendicular to the chains, favors non-collinear order in V chains, whereas it stabilizes the ferromagnetic (FM) order in Fe chains. Moreover, our calculations reveal a change in the magnetic order of V chains deposited on the Cu(110) surface in the presence of external EFs. In this case the NC spiral order, which was unstable in the absence of EF, becomes the most favorable one when perpendicular fields of the order of 0.1 V/Å are applied. As a final application of the theory we study the magnetic interactions within monoatomic TM chains deposited on graphene sheets. One observes that even weak chain substrate hybridizations can modify the magnetic order. Mn and Fe chains show incommensurable NC spin configurations. Remarkably, V chains show a transition from a spiral magnetic order in the freestanding geometry to FM order when they are deposited on a graphene sheet. Some TM-terminated zigzag graphene-nanoribbons, for example V and Fe terminated nanoribbons, also show NC spin configurations. Finally, the magnetic anisotropy energies (MAEs) of TM chains on graphene are investigated. It is shown that Co and Fe chains exhibit significant MAEs and orbital magnetic moments with in-plane easy magnetization axis. The remarkable changes in the magnetic properties of chains on graphene are correlated to charge transfers from the TMs to NN carbon atoms. Goals and limitations of this study and the resulting perspectives of future investigations are discussed.

Análisis de la crisis financiera de estados unidos (2007-2008) y la crisis de deuda (2011): su relación e impacto sobre uno de los fundamentales de la economía colombiana, la tasa de cambio

Este documento presenta una perspectiva de como una economía pequeña y abierta (en temas comerciales y de inversión) como la colombiana, se ve afectada por choques que sufren economías grandes como la estadounidense. Durante el periodo de estudio la economía de Estados Unidos sufrió dos choques: primero la crisis de las hipotecas subprime en los años 2007-2008; luego la crisis de deuda soberana de Estados Unidos en 2011. Estos dos choques afectaron la economía colombiana. En ambos casos, se puede establecer un hecho clave que detonó las crisis. En el primero, la entrada en el capítulo 11 de protección a bancarrotas por parte de Lehman Brothers, el 15 de septiembre de 2008. En el segundo, el detonante fue la baja de la calificación de la deuda soberana de Estados Unidos por parte de Standard and Poor´s el 5 de agosto de 2011. Estos días claves en las crisis, afectaron los principales índices de la bolsa de Estados Unidos, especialmente los relacionados con la actividad financiera, luego es de suponer que posiblemente también afectaron fundamentales de la economía colombiana como lo es la tasa de cambio peso-dólar (USD/COP). Este documento tiene como objeto principal, establecer el impacto de las crisis Norteamericana de 2007-2008 y de 2011, sobre la economía colombiana, específicamente sobre la tasa de cambio USD/COP. El documento también, analiza las causas que generaron dichas crisis en Estados Unidos, haciendo énfasis en la falta de regulación y control por parte de las instituciones del gobierno en la crisis de las hipotecas subprime. De igual forma se analiza el papel de las firmas calificadoras de riesgo, en la crisis de deuda estadounidense.

Incidencia de la evolución de los intereses estratégicos de Rusia y de Kazajstán en las dinámicas de cooperación bilateral. Periodo 1991 – 2004

El trabajo desarrolla la forma en la que evolucionaron las relaciones bilaterales entre Rusia y Kazajstán desde el periodo inmediatamente posterior a la caída de la URSS donde no existía una relación cercana, hasta el año 2001 donde se empieza a hablar de una cooperación entre los dos actores que llevó a una estrecha relación bilateral.

Análisis de las implicaciones del ascenso chino en el escenario internacional

El presente trabajo nace del interés por la creciente influencia de China en el mundo, principalmente, gracias a su acelerado crecimiento económico de los últimos años y a un estricto sistema de regulación por parte del Estado. Teniendo en cuenta lo anterior, se decidió hacer un análisis de las diferentes esferas o el contexto en el que se ha desarrollado un país que pasaba desapercibido hasta hace poco y que en la actualidad es considerado como la próxima potencia mundial. Aquí se presentan características del territorio, la población, el idioma, la política, la economía y otros aspectos importantes para este estudio. Adicionalmente, se presentan cifras que permiten observar con mayor claridad su evolución a lo largo del tiempo, su contribución a la economía mundial, las acciones del gobierno, y su situación actual a nivel tecnológico, científico, militar, ambiental, entre otros. Es así como, después de recopilar información de fuentes diversas, se procede a analizar las principales fortalezas y amenazas del ascenso chino, para, de esta manera, presentar un panorama sobre el futuro del mundo y de este país, si la situación continúa como hasta ahora. Por último, se llega a una serie de conclusiones con relación a lo anteriormente analizado y se plantean algunas recomendaciones para sobrellevar de una mejor manera los aspectos negativos que se identificaron durante la investigación.

Las regalías en Colombia y su impacto en el ámbito subnacional

Durante varios años se ha mantenido un fascinante debate sobre las regalías por lo que significanpara las finanzasde los entes subnacionales, por su impacto en el ámbito social y por su signifcado en materia tributaria para las empresas, entre otros. El objeto del presente trabajo es presentar el marco normativo que rige las regalías, las variables que las determinan desde el aspecto legal y su impacto; así como estudiar los posibles agrupamientos resultantes a nivel municipal y departamental teniendo como base un conjunto más amplio de variables diferentes al de las regalías.Respecto a los determinantes normativos se encontró que el monto de las regalías depende de la producción minera, del precio internacional del petróleo, del tipo de cambio y de la inflación. Desde el punto de vista de las entidades territoriales se encontró que las regalías asignadas dependen básicamente del PIB minero y que los ingresos tributarios departamentales y municipales no dependen del PIB no minero (PIB menos PIB minero). Finalmente, hay un grupo pequeño de entidades territoriales donde las regalías tienen cierto impacto, esto siembra una inquietud con respecto al mandato constitucional que señala que “el Estado es propietario del subsuelo y de los recursos naturales no renovables”, con lo cual el impacto debería abarcar buena parte del territorio nacional.-----For several years has been hold a fascinating debate on royalties, because of what they mean for the financesof the subnational entities, their social impact and its meaning in tax matters for companies, among others issues. The objective of this work is to present the regulatory framework governing royalties currently, show the variables that determine them from legal order and its impact; as well as studying the possible resulting groupings at the municipal and departmental levels taking as a basis a broader set of variables different of royalties.Respect to normative determinants, it was found that the amount of the royalties depends on mining production, the international oil prices, exchange rate and inflation. From the point of view of the territorial entities, it was found that assigned royalties are basically dependent on mining GDP. Meanwhile, departmental and municipal tax revenues are not dependent on GDP without mining (mining excluded from GDP). Finally, there are a small group of territorial entities where royalties have some impact, leaving some concern regarding to the constitutional mandate pointing to “the State owns the subsoil and non-renewable natural resources”, where the impact should covers most of the national territory.

Estudio de caso- lanzamiento de la marca Davivienda en Costa Rica, el Salvador y Honduras

Este documento tiene como propósito reunir y analizar el universo de información disponible al respecto del proceso de Lanzamiento de la Marca Davivienda en tres mercados Centroamericanos: Costa Rica, El Salvador y Honduras y así, lograr aprovechar al máximo las experiencias y lecciones aprendidas por la entidad durante este período. Para este propósito, la estructura del trabajo consta de un marco teórico que contempla las teorías sobre el posicionamiento de marca, procediendo a un estudio de caso formal. Este estudio se compone inicialmente de la descripción del Banco Davivienda y los países en los que la entidad ingresó tras la adquisición de la operación de HSBC. Posteriormente, se analiza el proceso del Lanzamiento de Marca desde la formulación e implementación de la estrategia hasta la evaluación y análisis de los resultados obtenidos. Por último, se presentan las conclusiones y recomendaciones con base en la teoría, resultados y aprendizajes.