Managerial failure in mid-Victorian Britain?: Corporate expansion during a promotion boom

This article examines the mid-1840s expansion of the British railway network, which was associated with a large deterioration in shareholder value. Using a counterfactual approach and new data on railway competition, we argue that the expansion of the railway companies, and their subsequent decline in financial performance, was not due to managerial failure. Rather, the promotion of new routes by established railways and mergers with other companies was part of a managerial strategy to maintain incumbent positions, and may have been preferable to not expanding whilst their competitors did.

A DFT study of the transition metal promotion effect on ethylene chemisorption on Co(0001)

Transition metals are often introduced to a catalyst as promoters to improve catalytic performance. In this work, we study the promotion effect of transition metals on Co, the preferred catalytic metal for Fischer-Tropsch synthesis because of its good compromise of activity, selectivity and stability, for ethylene chemisorption using density functional theory (DFT) calculations, aiming to provide some insight into improving the alpha-olefin selectivity. In order to obtain the general trend of influence on ethylene chemisorption, twelve transition metals (Zr, Mn, Re, Ru, Rh, It, Ni, Pd, Pt, Cu, Ag and Au) are calculated. We find that the late transition metals (e.g. Pd and Cu) can decrease ethylene chemisorption energy. These results suggest that the addition of the late transition metals may improve alpha-olefin selectivity. Electronic structure analyses (both charge density distributions and density of states) are also performed and the understanding of calculated results is presented. (C) 2009 Elsevier B.V. All rights reserved.

Caught in a 'spiral': barriers to healthy eating and dietary health promotion needs from the perspective of unemployed young people and their service providers

The number of young people in Europe who are not in education, employment or training (NEET) is increasing. Given that young people from disadvantaged backgrounds tend to have diets of poor nutritional quality, this exploratory study sought to understand barriers and facilitators to healthy eating and dietary health promotion needs of unemployed young people aged 16-20 years. Three focus group discussions were held with young people (n=14). Six individual interviews and one paired interview with service providers (n=7). Data were recorded, transcribed verbatim and thematically content analysed. Themes were then fitted to social cognitive theory (SCT). Despite understanding of the principles of healthy eating, a ‘spiral’ of interrelated social, economic and associated psychological problems was perceived to render food and health of little value and low priority for the young people. The story related by the young people and corroborated by the service providers was of a lack of personal and vicarious experience with food. External, environmental factors such as the proliferation and proximity of fast food outlets and the high perceived cost of ‘healthy’ compared to ‘junk’ food rendered the young people low in self-efficacy and perceived control to make healthier food choices. Agency was instead expressed through consumption of junk food and substance abuse. Both the young people and service providers agreed that for dietary health promotion efforts to succeed, social problems needed addressed and agency encouraged through (individual and collective) active engagement of the young people themselves.

‘Plugging the Gap’: Shared Education and the promotion of community relations through schools in Northern Ireland

Although there is no consensus amongst educationalists as to the role schools play as drivers of hostilities in divided societies, there is broad agreement that they can facilitate more positive intergroup relations. In Northern Ireland the promotion of school based inter-group contact has been offered as a means through which this can happen. Until 2007, the approach was twofold, reflected on the one hand in short-term contact opportunities for pupils in predominantly Catholic and Protestant schools, and on the other, in support for integrated schools which educate Catholics and Protestants together. In 2007 the Shared Education Programme was introduced to ‘bridge the gap’ between short-term opportunities for contact, and ‘full immersion’ integrated schools. Informed by contact theory, shared education offers curriculum based interaction between pupils attending all school types, aimed at promoting the type of contact likely to reduce negative social attitudes and ultimately contribute to social harmony. In this paper, we examine the impact of shared education thus far. Our analysis suggests that whilst shared education is generally effective in promoting positive assessments of other group members, there is a danger that programme impact may be inhibited by the foregrounding of educational over reconciliation priorities. Appreciating that the downplaying reconciliation objectives may have been necessary when the programme was established in order to maximize recruitment to it, we argue that if the full potential of shared education is to be realized, moving forward, it is important for schools to engage with issues of group differences.

Sector analysis provides additional spatial information on the permanent prostate brachytherapy learning curve

PURPOSE: To evaluate the permanent prostate brachytherapy (PPB) learning curve using postimplant multisector dosimetric analysis and to assess the correlation between sector -specific dosimetry and patient-reported outcome measures (PROMs).

METHODS AND METHODS: First 200 patients treated with (125)I PPB monotherapy (145 Gy) at a single institution were assessed. Postimplant dosimetry (PID) using CT was evaluated for whole prostate (global) and 12 sectors, assessing minimum dose to 90% of prostate (D90) and dose to 0.1 cm(3) of rectum (D0.1cc). Global and sector PID results were evaluated to investigate changes in D90 with case number. Urinary and bowel PROMs were assessed using the International Prostate Symptom Score and the Expanded Prostate Cancer Index Composite questionnaire. The correlation between global and individual sector PID and urinary/bowel PROMs was also evaluated.

RESULTS: Linear regression confirmed a significant improvement in global D90 with case number (r(2) = 0.20; p = 0.001) at a rate of 0.11 Gy/case. Postimplant D90 of base sectors increased at a rate of 0.11-0.15 Gy/case (p = 0.0001) and matched global improvement. The regression lines of midgland and apex sectors were significantly different from global D90 (p = 0.01). Posterior midgland sectors showed a significant reduction in D90 with case number at a rate of 0.13-0.19 Gy/case (p = 0.01). Dose to posterior midgland sectors correlated with rectal D0.1cc dose but not bowel PROMs. Dose to posterior midgland sectors correlated with urinary International Prostate Symptom Score change, which was not apparent when global D90 alone was considered.

CONCLUSIONS: Sector analysis provided increased spatial information regarding the PPB learning curve. Furthermore, sector analysis correlated with urinary PROMs and rectal dose.

The role of low coverage sodium surface species on electrochemical promotion in a Pt/YSZ system

The effect of sodium-modification on the catalyst and electrocatalytic properties of a platinum catalyst supported on a YSZ solid electrolyte was studied. Increasing the sodium coverage on the catalyst surface appears to block some of the three-phase boundary (tpb) sites and reduces the rate of the charge transfer reaction. The promotion of the platinum surface reaction (ethylene oxidation) seems to a first approximation to be a function of the rate of oxygen supply or removal to or from the surface irrespective of whether this is contaminated by sodium or not (samples with sodium contamination require a higher overpotential to achieve the same current density as a clean sample because of poisoning in the tpb). At high negative polarisations (oxygen removed from the surface) the sodium contaminated samples show a significant increase in rate, possibly due to the decomposition of e.g. sodium hydroxides and carbonates. © 2012 Elsevier B.V.

Electrochemical promotion of a Pt catalyst supported on La 0.6Sr 0.4Co 0.2Fe 0.8O 3 - δ hollow fibre membranes

The use of wireless electrochemical promotion of catalysis (EPOC) of a Pt catalyst supported on a mixed ionic electronic conducting hollow fibre membranes is investigated. This reactor configuration offers high surface areas per unit volume and is ideally suited for scaled-up applications. The MIEC membrane used is the La _0.6Sr _0.4Co _0.2Fe _0.8O ₃ perovskite (LSCF) with a Pt catalyst film deposited on the outer surface of the LSCF membrane. Experimental results showed that after initial catalyst deactivation (in the absence of an oxygen chemical potential difference across the membrane) the catalytic rate can be enhanced by using an oxygen sweep and wireless EPOC can be used for the in situ regeneration of a deactivated catalyst. © 2012 Elsevier B.V.

In situ catalyst activity control in a novel membrane reactor-Reaction driven wireless electrochemical promotion of catalysis

A dual chamber membrane reactor was used in order to study the effect of macroscopically applied oxygen chemical potential differences to a platinum catalyst supported on a mixed oxygen ion and electronic conducting membrane. It is believed that the oxygen chemical potential difference imposed by the use of an oxygen sweep in one of the reactor chambers causes the back-spillover of oxygen species from the support onto the catalyst surface, resulting in the modification of the catalytic activity. The use of different sweep gases, such as ethylene and hydrogen was investigated as the means to reverse the rate modification by removing the spilt over species from the catalyst surface and returning the system to its initial state. Oxygen sweep in general had a positive effect on the reaction rate with rate increases up to 20% measured. Experimental results showed that hydrogen is a more potent sweep gas than ethylene in terms of the ability to reverse rate modification. A 10% rate loss was observed when using an ethylene sweep as compared with an almost 60% rate decrease when hydrogen was used as the sweep gas. © 2009 Elsevier Ltd. All rights reserved.

Comparative studies between classic and wireless electrochemical promotion of a Pt catalyst for ethylene oxidation

A comparative study between a classic and a wireless electrochemical promotion experiment was undertaken as a tool towards the better understanding of both systems. The catalytic modification of a platinum catalyst for ethylene oxidation was studied. The catalyst was supported on yttria-stabilised-zirconia (YSZ), a known pure oxide ion conductor, for the classic experiment and La _0.6Sr_0.4Co_0.2Fe_0.8O _3-δ-a mixed oxide ion electronic conductor-was used for the wireless experiment. The two systems showed certain similarities in terms of the reaction classification (in both cases electrophobic behaviour was observed) and the promotion mechanism. Significant difference was observed in the time scales and the reversibility of the induced rate modification. © 2008 Springer Science+Business Media B.V.

Electrochemical promotion of a metal catalyst supported on a mixed-ionic conductor

It has been found that the catalytic activity and selectivity of a metal film deposited on a solid electrolyte could be enhanced dramatically and in a reversible way by applying an electrical current or potential between the metal catalyst and the counter electrode (also deposited on the electrolyte). This phenomenon is know as NEMCA [S. Bebelis, C.G. Vayenas, Journal of Catalysis, 118 (1989) 125-146.] or electrochemical promotion (EP) [J. Prichard, Nature, 343 (1990) 592.] of catalysis. Yttria-doped barium zirconate, BaZr_0.9Y_0.1O_{3 - α} (BZY), a known proton conductor, has been used in this study. It has been reported that proton conducting perovskites can, under the appropriate conditions, act also as oxide ion conductors. In mixed conducting systems the mechanism of conduction depends upon the gas atmosphere that to which the material is exposed. Therefore, the use of a mixed ionic (oxide ion and proton) conducting membrane as a support for a platinum catalyst may facilitate the tuning of the promotional behaviour of the catalyst by allowing the control of the conduction mechanism of the electrolyte. The conductivity of BZY under different atmospheres was measured and the presence of oxide ion conduction under the appropriate conditions was confirmed. Moreover, kinetic experiments on ethylene oxidation corroborated the findings from the conductivity measurements showing that the use of a mixed ionic conductor allows for the tuning of the reaction rate. © 2006 Elsevier B.V. All rights reserved.

Electrochemical promotion of catalysis using solid-state proton-conducting membranes

A solid-state electrochemical reactor with ceramic proton-conducting membrane has been used to study the effect of electrochemically induced hydrogen spillover on the catalytic activity of platinum during ethylene oxidation. Suitable proton-conducting electrolyte membranes (Gd-doped BaPrO ₃ (BPG) and Y-doped BaZrO₃ (BZY)) were fabricated. These materials were chosen because of their protonic conductivity in the operational temperature region of the reaction (400-700 °C). The BZY-based electrochemical cell was used to investigate the open-circuit voltage (OCV) dependence on H₂ partial pressure with comparison being made to the theoretical OCV as predicted by the Nernst equation. Furthermore, the BZY pellets were used to study the effect of proton transfer of the catalytic activity of platinum during ethylene oxidation. The reaction was found to exhibit electrochemical promotion at 400 °C and to be electrophilic in nature, i.e. proton addition to the platinum surface resulted in an increase in reaction rate. At higher temperatures, the rate was not affected, within experimental error, by proton addition or removal. Under similar conditions, AC impedance showed that there was a large overall cell resistance at 400 °C with significantly decreased resistance at higher temperatures. It is possible that there could be a relationship between large cell resistances and the onset of electrochemical promotion in this system but there is, as yet, no conclusive evidence for this. © 2003 Elsevier B.V. All rights reserved.