The term structure of inflation compensation in the nominal yield curve

We propose a DSGE model with regime switching in the central bank’s inflation target to explain inflation compensation in the UK. Taking advantage of the well-documented change in UK monetary policy to adopt inflation targeting, we estimate our model using nominal and inflation-linked Treasury bond data from the UK from 1985 to 2007. We find that this model can account for the term structure of inflation compensation in the nominal yield curve by generating regime-dependent conditional expectations of future inflation.Inflation targeting ; Monetary policy - Great Britain

Simple ways to forecast inflation: what works best?

There are many ways to forecast the future rate of inflation, ranging from sophisticated statistical models involving hundreds of variables to hunches based on past experience. We generate a number of forecasts using a simple statistical model and an even simpler estimating rule, adding in various measures thought to be helpful in predicting the course of inflation. Then we compare their forecast accuracy. We find that no single specification outperforms all others over all time periods. For example, the median and 16 percent trimmed-mean measures outperform all other specifications during the 1990s, and survey-based inflation expectations seem to do better during volatile periods.Inflation (Finance) ; Forecasting

Principal Lenders to Uganda

This report provides a summary of public debt of Uganda specifically focusing on its external debt. A similar but limited search for Kenya is also presented as comparison. The types of lending products in terms of loan, grant, technical assistance and loan guarantees; the financial terms of these products (interest rates, tenors, grace periods, applicable commitment and service fees and non-financial terms available are presented). As a country comparison, external borrowing of Kenya is also covered in a similar but limited approach. Public Debt of Uganda is presented in Section 2 in terms of domestic and external financing in different lending products. Section 3 represents the search for external lending in terms of available data provided by the lenders websites. For Uganda, WBG (40% of total debt stock) and AfDB (16% of total debt stock) are the main multilateral lenders whereas China (25% of total debt stock) and Japan (4% of total debt stock) bilateral credits are analysed as the bilateral lenders. The current active loans with project names, available financial terms and non-financial terms are presented in this section. Section 4 covers the external lending figures of Kenya in a similar but a limited approach. As these lenders are providing similar financial and non-financial terms applicable to these countries, the general characteristics of the loan terms provided to Kenya is like the ones in Uganda. Due to the specific nature of this review, the main sources of information used were the websites of the country’s statistics, financial and budget performance reports, lenders’ websites and some academic literature and reviews to provide background information and other comprehensive reviews. There is very limited information on the agreement specific terms for non-financial issues for bilateral lenders. Financial and non-financial terms loan by loan was not available for some lenders. Based on the available information in lender websites, the guidelines of WBG and AfDB Group are reviewed in this report

Effects of the real exchange rate on output and inflation: Evidence from Turkey

This paper assesses the effects of real depreciation on the economic performance of Turkey by considering quarterly data from 1987:I to 2001:III. The empirical evidence suggests that, contrary to classical wisdom, the real depreciations are contractionary, even when external factors like world interest rates, international trade, and capital flows are controlled. Moreover, the results obtained from the analyses indicate that real exchange rate depreciations are inflationary

Transient analysis of proton electrolyte membrane fuel cells (PEMFC) at start-up and failure

A two-dimensional, transient, single-phase computational model, incorporating water transport in the membrane and the flow and transport of species in porous gas diffusion electrodes is developed to evaluate the transient performance of a PEMFC with interdigitated gas distributors. The co-flow and counter-flow of the anode and cathode reactants are discussed to address their effects on PEMFC performance and transients. The important role of water transport in the membrane on the transients is demonstrated. The membrane’s water intake or outtake determines the duration of the transients. The effect of the operating conditions on steady state and transient performances is outlined. Overshoots and undershoots are observed in the average current density, due to a step change in the cell voltage and the cathode pressure under start-up conditions. Simulation results are used to address the role of auxiliary components in the failure modes of the PEMFC

FuelCell2009-85041 Influence of Ammonia on Membrane-Electrode Assemblies in Polymer Electrolyte Fuel Cells

Abstract An experimental investigation of contamination of polymer electrolyte fuel cell (PEFC) membranes and catalyst layers with ammonia (NH 3 ) is reported. Cyclic voltammetry (CV) scans and electrochemical impedance spectroscopy (EIS) analyses show that trace amounts of ammonia can significantly contaminate both the polymer electrolyte membrane (PEM) and the catalyst layers. The results show that the catalyst layer contamination can be reversed under certain conditions, while the membrane recovery tends to be much slower, and permanent effects of ammonia contamination is observed. Mechanisms of contamination of the polymer electrolyte and catalyst layers, and performance degradation of the PEFC are also postulated. Introduction Ammonia (NH 3 ) is a potential hydrogen carrier due to its high hydrogen capacity (18% by weight) 1 . To generate hydrogen for fuel cell applications, ammonia is reformed, either by cracking 2-3 or through metal hydride reaction

Modeling the effect of inhomogeneous compression of GDL on local transport phenomena in a PEM fuel cell

The effects of inhomogeneous compression of gas diffusion layers (GDLs) on local transport phenomena within a polymer electrolyte membrane (PEM) fuel cell were studied theoretically. The inhomogeneous compression induced by the rib/channel structure of the flow field plate causes partial deformation of the GDLs and significantly affects material parameters. The results suggest that inhomogeneous compression does not significantly affect the polarization behavior or gas-phase mass transport. However, the effect of inhomogeneous compression on the current density distribution is evident. Local current density under the channel was substantially smaller than under the rib when inhomogeneous compression was taken into account, while the current density distribution was fairly uniform for the model which excluded the effect of inhomogeneous compression. This is caused by the changes in the selective current path, which is determined by the combinations of conductivities of components and contact resistance between them. Despite the highly uneven current distribution and variation in material parameters as a function of GDL thickness, the temperature profile was relatively even over the active area for both modeled cases, contrary to predictions in previous studies. However, an abnormally high current density significantly accelerates deterioration of the membrane and is critical in terms of cell durability. Therefore, fuel cells should be carefully designed to minimize the harmful effects of inhomogeneous compression

The effects of water and microstructure on the performance of polymer electrolyte fuel cells

n this paper, we present a comprehensive non-isothermal, one-dimensional model of the cathode side of a Polymer Electrolyte Fuel Cell. We explicitly include the catalyst layer, gas diffusion layer and the membrane. The catalyst layer and gas diffusion layer are characterized by several measurable microstructural parameters. We model all three phases of water, with a view to capturing the effect that each has on the performance of the cell. A comparison with experiment is presented, demonstrating excellent agreement, particularly with regard to the effects of water activity in the channels and how it impacts flooding and membrane hydration. We present several results pertaining to the effects of water on the current density (or cell voltage), demonstrating the role of micro-structure, liquid water removal from the channel, water activity, membrane and gas diffusion layer thickness and channel temperature. These results provide an indication of the changes that are required to achieve optimal performance through improved water management and MEA-component design. Moreover, with its level of detail, the model we develop forms an excellent basis for a multi-dimensional model of the entire membrane electrode assembly

Visualisation of water droplets during the operation of PEM fuel cells

A transparent proton exchange membrane fuel cell (PEMFC) has been designed to enable visualisation of water droplets during its operation. Images of the formation of droplets on the surface of the gas diffusion layer (GDL) on its cathode side, which result in water accumulation and blockage to the airflow channels, were recorded using a CCD camera. Measurement of the cell current and droplet characterisation have been carried out simultaneously and the effect of the airflow and external resistive load has been quantified. The droplet images show that water accumulation occurs first in the middle channels of a serpentine reactant-flow fuel cell design and that no droplets are formed at the bends of the flow channels. Water blockage to the airflow path was caused by the overlapping of two land-touching droplets developing on each side of the channel. Flooding was found to be more susceptible to the airflow than the other test operating conditions

Water droplet accumulation and motion in PEM (Proton Exchange Membrane) fuel cell mini-channels

Effective water management is one of the key strategies for improving low temperature Proton Exchange Membrane (PEM) fuel cell performance and durability. Phenomena such as membrane dehydration, catalyst layer flooding, mass transport and fluid flow regimes can be affected by the interaction, distribution and movement of water in flow plate channels. In this paper a literature review is completed in relation to PEM fuel cell water flooding. It is clear that droplet formation, movement and interaction with the Gas Diffusion Layer (GDL) have been studied extensively. However slug formation and droplet accumulation in the flow channels has not been analysed in detail. In this study, a Computational Fluid Dynamic (CFD) model and Volume of Fluid (VOF) method is used to simulate water droplet movement and slug formation in PEM fuel cell mini-channels. In addition, water slug visualisation is recorded in ex situ PEM fuel cell mini-channels. Observation and simulation results are discussed with relation to slug formation and the implications to PEM fuel cell performance