Electrochemical promotion of catalysis controlled by chemical potential difference across a mixed ionic-electronic conducting ceramic membrane - An example of wireless NEMCA

A La_0.6Sr_0.4Co_0.2F_0.8O₃ mixed ionic electronic conducting (MIEC) membrane was used in a dual chamber reactor for the promotion of the catalytic activity of a platinum catalyst for ethylene oxidation. By controlling the oxygen chemical potential difference across the membrane, a driving force for oxygen ions to migrate across the membrane and backspillover onto the catalyst surface is established. The reaction is then promoted by the formation of a double layer of oxide anions on the catalyst surface. Thelectronic conductivity of the membrane material eliminates the need for an external circuit to pump the promoting oxide ion species through the membrane and onto the catalyst surface. This renders this "wireless" system simpler and more amenable for large-scale practical application. Preliminary experiments show that the reaction rate of ethylene oxidation can indeed be promoted by almost one order of magnitude upon exposure to an oxygen atmosphere on the sweep side of the membrane reactor, and thus inducing an oxygen chemical potential difference across the membrane, as compared to the rate under an inert sweep gas. Moreover, the rate does not return to its initial unpromoted value upon cessation of the oxygen flow on the sweep side, but remains permanently promoted. A number of comparisons are drawn between the classical electrochemical promotion that utilises an external circuit and the "wireless" system that utilises chemical potential differences. In addition a 'surface oxygen capture' model is proposed to explain the permanent promotion of the catalyst activity. © 2007 Springer Science+Business Media, LLC.

European urban spaces in crisis - the mapping of affective pracitices with Living with Difference: introduction

The introduction outlines the notion of urban space and crisis in Europe while taking into account the more recent protests and riots in different cities, in and beyond Europe. It is argued that the phenomen of protest is happening alongside the economic crisis underscoring an alternative political public civic spirit expressing to a certain degree the renaissance and timely making of, what might be called in the digital age, #œuvre. Its forces and emotional properties capture a political realm that unfolds as a globalized urban transnational public space, still progressing. Further, it introduces the collection of papers for the special themed feature. Five papers look at affective practices through a Continental European lens, which places the meaning of race, migration and intersecting identity angles at the centre of debates of individual encounters in public spaces. The final and sixth paper, written by Brenda Yeoh, looks through a Singapore/East Asia lens, and comments on the common European threats as well as on the historical specificity and implications of distinctive geo-political spaces for affective practices.

Memory Cost Analysis for OpenFlow Multiple Table Lookup

Multiple Table Lookup architectures in Software Defined Networking (SDN) open the door for exciting new network applications. The development of the OpenFlow protocol supported the SDN paradigm. However, the first version of the OpenFlow protocol specified a single table lookup model with the associated constraints in flow entry numbers and search capabilities. With the introduction of multiple table lookup in OpenFlow v1.1, flexible and efficient search to support SDN application innovation became possible. However, implementation of multiple table lookup in hardware to meet high performance requirements is non-trivial. One possible approach involves the use of multi-dimensional lookup algorithms. A high lookup performance can be achieved by using embedded memory for flow entry storage. A detailed study of OpenFlow flow filters for multi-dimensional lookup is presented in this paper. Based on a proposed multiple table lookup architecture, the memory consumption and update performance using parallel single field searches are evaluated. The results demonstrate an efficient multi-table lookup implementation with minimum memory usage.

Recognising difference while promoting cohesion: the role of collaborative networks in education

The chapter outlines various approaches taken to the challenge of divided societies through education systems and links this to debates on political approaches to conflict resolution in Northern Ireland. The education debate has structural and affective components, while the political debate revolves around the privileging of identity or commonality. Applying the principle of recognition and the importance of tolerance is seen to provide a range of policy options, but the evidence of education interventions in Northern Ireland does not highlight any one policy option as the most effective, nor did the end of the violent conflict produce a new consensus on a way forward. The chapter argues that a key additional element to effective practice might be provided through the promotion of shared education through collaborative networks of schools which allows for the continued operation of separate schools while promoting an integrated experience for pupils and teachers.

Binaural Reproduction of Finite Difference Simulations Using Spherical Array Processing

Due to its efficiency and simplicity, the finite-difference time-domain method is becoming a popular choice for solving wideband, transient problems in various fields of acoustics. So far, the issue of extracting a binaural response from finite difference simulations has only been discussed in the context of embedding a listener geometry in the grid. In this paper, we propose and study a method for binaural response rendering based on a spatial decomposition of the sound field. The finite difference grid is locally sampled using a volumetric array of receivers, from which a plane wave density function is computed and integrated with free-field head related transfer functions, in the spherical harmonics domain. The volumetric array is studied in terms of numerical robustness and spatial aliasing. Analytic formulas that predict the performance of the array are developed, facilitating spatial resolution analysis and numerical binaural response analysis for a number of finite difference schemes. Particular emphasis is placed on the effects of numerical dispersion on array processing and on the resulting binaural responses. Our method is compared to a binaural simulation based on the image method. Results indicate good spatial and temporal agreement between the two methods.

Do Gifts Increase Consent to Home-based HIV Testing? A Difference-in-differences Study in Rural KwaZulu-Natal, South Africa

Background Despite the importance of HIV testing for controlling the HIV epidemic, testing rates remain low. Efforts to scale-up testing coverage and frequency in hard-to-reach and at-risk populations commonly focus on home-based HIV testing. This study evaluates the effect of a gift (a food voucher for families, worth US$ 5) on consent rates for home-based HIV testing.
Methods We use data on 18,478 men and women who participated in the 2009 and 2010 population-based HIV surveillance carried out by the Wellcome Trust Africa Centre for Health and Population Studies in rural KwaZulu-Natal, South Africa. Our quasi-experimental difference-in-differences approach controls for unobserved confounding in estimating the causal effect of the intervention on HIV testing consent rates.
Results Allocation of the gift to a family in 2010 increased the probability of family members consenting to test in 2010 by 25 percentage points (95% CI 21-30; p<0.001). The intervention effect persisted, slightly attenuated, in the year following the intervention (2011), further increasing intervention value for money.
Conclusions In HIV hyperendemic settings a gift can be highly effective at increasing consent rates for home-based HIV testing. Given the importance of HIV testing for treatment uptake and individual health, as well as for HIV treatment-and-prevention strategies and for monitoring the population impact of the HIV response, gifts should be considered as a supportive intervention for HIV testing initiatives where consent rates have been low.

Counter-Mappings: Cartography and Difference

Introduction to the co-edited book 'Cartographies of Differences: Interdisciplinary Perspectives

Visible Difference, Stigmatising Language(s) and the Distinctive Construction of Prejudices against Others in Leeds and Warsaw

The chapter argues that language and cultural communication matter in a transnational world and that the transmission of prejudices against minorities has to be closely analysed while contextualising national histories with minorities. Looking at two spatial sites (Leeds and Warsaw) and analysing interview material that was drawn from a larger study, the authors discuss the way local people address difference particularly through the axes of gendered ethnicity (Muslim men) and gendered class (male underclass). It explores how the same categories of difference are discursively produced in Poland and the UK/ England; to what degree they differ or overlap.

Influence of Soil and Irrigation Management on the Quality of Seedless Crimson Table Grapes

The market for table grapes is moving into mass production of specialty seed-less grapes in covered areas, aiming at obtaining premium prices with early or late production of high quality products. Production of quality seedless grapes is not straightforward since it is requires the correct combination of various independent characteristics, such as color, sugars, size and quantity at the right moment for successful harvesting and marketing. The present study was carried out at the two largest Portuguese producers located in Alentejo, and has the objective of studying the effect of irrigation management strategies and two different soils on the various relevant parameters for successful production and marketing. The management strategies were the application of ten day stress at the end of the cycle, in order to promote early maturing of the grapes. Three different timings of the stress were applied. Soil moisture, sap flow, bark thickness, as well as leaf water potential, stomatal conductance and chlorophyll content were measured regularly during the production season. The results indicate that the roots explore a rather large soil volume and the plants can successfully withstand reasonable periods of drought without significant changes to the plant physiology. Additionally late rains can mask the effect of any farmer applied drought and invalidate any farmer induced stress to the plants. Water-logged soils tend to cause early onset of maturity, but cause the ripening stage to extend over a longer period of time, and thus, in effect result in a delay in the harvest date. Topography also has some effect on the ripening, since hot air tends to accumulate under the plastic at the higher areas of the field. This work is funded by PRODER, 4.1, within the scope of project MORECRIMSON

Seismic retrofitting of RC buildings using CFRP and post-tensioned metal straps: shake table tests

This article examines the effectiveness of two innovative retrofitting solutions at enhancing the seismic behaviour of a substandard reinforced concrete building tested on a shake table as part of the Pan-European funded project BANDIT. To simulate typical substandard construction, the reinforcement of columns and beam-column joints of the full-scale structure had inadequate detailing. An initial series of shake table tests were carried out to assess the seismic behaviour of the bare building and the effectiveness of a first retrofitting intervention using Post-Tensioned Metal Straps. After these tests, columns and joints were repaired and subsequently retrofitted using a retrofitting solution consisting of Carbon Fibre Reinforced Polymers and Post-Tensioned Metal Straps applied on opposite frames of the building. The building was then subjected to unidirectional and three-dimensional incremental seismic excitations to assess the effectiveness of the two retrofitting solutions at improving the global and local building performance. The article provides details of the above shake table testing programme and retrofitting solutions, and discusses the test results in terms of the observed damage, global damage indexes, performance levels and local strains. It is shown that whilst the original bare building was significantly damaged at a peak ground acceleration (PGA) of 0.15g, the retrofitted building resisted severe threedimensional shake table tests up to PGA=0.60g without failure. Moreover, the retrofitting intervention enhanced the interstorey drift ratio capacity of the 1st and 2nd floors by 160% and 110%, respectively. Therefore, the proposed dual retrofitting system is proven to be very effective for improving the seismic performance of substandard buildings.

Full-Scale Shaking Table Tests on a Substandard RC Building Repaired and Strengthened with Post-Tensioned Metal Straps

The effectiveness of a novel Post-Tensioned Metal Strapping (PTMS) technique at enhancing the seismic behaviour of a substandard RC building was investigated through full-scale shake-table tests during the EU-funded project BANDIT. The building had inadequate reinforcement detailing in columns and joints to replicate old construction practices. After the bare building was initially damaged significantly, it was repaired and strengthened with PTMS to perform additional seismic tests. The PTMS technique improved considerably the seismic performance of the tested building. Whilst the bare building experienced critical damage at an earthquake of PGA=0.15g, the PTMS-strengthened building sustained a PGA=0.35g earthquake without compromising stability.