Novel photocatalyst-based colourimetric indicator for oxygen: Use of a platinum catalyst for controlling response times

The preparation and characterisation of a novel, UV-activated, solvent-based, colourimetric indicator for oxygen is described, comprising a redox dye (methylene blue, MB), semiconductor photocatalyst (Pt-TiO2), and a sacrificial electron donor (SED = glycerol), all dispersed/dissolved in a polymer medium (sulfonated polystyrene. SPS). Upon exposure to UVA light, the Pt-TiO2/MB/glycerol/SPS oxygen indicator is readily photobleached as the MB is converted into its oxygen-sensitive, leuco form, LMB. In contrast to its non-platinised TiO2 counterpart (TiO2/MB/glycerol/SPS oxygen indicator), the recovery of the original colour is faster (ca. 1.5 days cf. 5 days at 21 degrees C). This is due to the catalytic action of the 0.38 wt% platinum loaded onto the semiconductor photocatalyst. TiO2, on the oxidation of the photogenerated LMB by ambient O-2. Furthermore, by increasing the level of platinum loading, recovery times can be decreased further; e.g. a Pt-TiO2/MB/glycerol/SPS oxygen indicator with platinum level of 1.52 wt% recovers fully within 12 h. A study of the kinetics of recovery as a function of film thickness revealed the recovery step is not controlled by the diffusion of O-2 through the film, but instead dependent upon the slow rate of oxidation of LMB to MB by O-2 in the low dielectric polymer encapsulation medium. Other work showed this recovery is only moderately dependant upon temperatures above -10 degrees C and very sensitive to relative humidity above 30% RH. Potential uses of this UV light activated indicator are discussed briefly. (C) 2011 Elsevier B.V. All rights reserved.

A Bayesian network hybrid model for representing accident and emergency waiting times

The paper introduces a new modeling approach that represents the waiting times in an accident and emergency (A&E) department in a UK based national health service (NHS) hospital. The technique uses Bayesian networks to capture the heterogeneity of arriving patients by representing how patient covariates interact to influence their waiting times in the department. Such waiting times have been reviewed by the NHS as a means of investigating the efficiency of A&E departments (emergency rooms) and how they operate. As a result activity targets are now established based on the patient total waiting times with much emphasis on trolley waits.

Good things come to those who wait:Time discounting differences between adult offenders and nonoffenders

Criminal behavior has been explained by the idea that offenders have a lack of self-control. Yet, Wilson and Daly reported that juvenile offenders exhibit time-discounting tendencies similar to those of nonoffending juveniles. As no previous study has compared time-discounting behavior of adult offenders with nonoffenders, we raise the question, do adult offenders exhibit shorter time horizons or the tendency to discount future rewards? To answer this question, 89 offenders (ex-prisoners and prisoners) and 106 nonoffenders completed a time-discounting measure containing 27 different monetary choices. Our results show that, counter to findings with juvenile offenders, adult offenders (ex-prisoners) exhibit significantly shorter time horizons and discount more than nonoffenders as delayed payoffs increase to medium and large rewards. Furthermore, both offenders and nonoffenders are less likely to discount as the reward of future gains increases to medium and large.

Delay times and rates for Type Ia supernovae and thermonuclear explosions from double-detonation sub-Chandrasekhar mass models

We present theoretical delay times and rates of thermonuclear explosions that are thought to produce Type Ia supernovae (SNe Ia), including the double-detonation sub-Chandrasekhar mass model, using the population synthesis binary evolution code startrack. If detonations of sub-Chandrasekhar mass carbon-oxygen white dwarfs following a detonation in an accumulated layer of helium on the white dwarf's surface ('double-detonation' models) are able to produce thermonuclear explosions which are characteristically similar to those of SNe Ia, then these sub-Chandrasekhar mass explosions may account for at least some substantial fraction of the observed SN Ia rate. Regardless of whether all double-detonations look like 'normal' SNe Ia, in any case the explosions are expected to be bright and thus potentially detectable. Additionally, we find that the delay time distribution of double-detonation sub-Chandrasekhar mass SNe Ia can be divided into two distinct formation channels: the 'prompt' helium-star channel with delay times

Improving MTM-UAS to predetermine automotive maintenance times

The preventive knowledge of serviceability times is a critical factor for the quantification of after-sales services costs of a vehicle. Predetermined motion time system are frequently used to set labor rates in industry by quantifying the amount of time required to perform specific tasks. The first such system is known as Methods-time measurement (MTM). Several variants of MTM have been developed differing from each other on their level of focus. Among them MTM-UAS is suitable for processes that average around 1-3 min. However experimental tests carried out by the authors in Elasis (Research Center of FIAT Group) demonstrate that MTM-UAS is not the optimal approach to measure serviceability times. The reason is that it doesn't take into account ergonomic factors. In the present paper the authors propose to correct the MTM-UAS method including in the task analysis the study of human postures and efforts. The proposed approach allows to estimate with an "acceptable" error the time needed to perform maintenance tasks since the first phases of product design, by working on Digital Mock-up and human models in virtual environment. As a byproduct of that analysis, it is possible to obtain a list of maintenance times in order to preventively set after-sales service costs. © 2012 Springer-Verlag.

MacIntyre and Havel as green political thinkers: Unreasonable thinking in turbulent times

Purpose This chapter explores the ideas of Alasdair MacIntyre and Vaclav Havel and what these two thinkers can contribute to green political theory. Design/methodology/approach This chapter includes examination of some of the key works of Havel and MacIntyre and analysis of these works from the point of view of green political theory. Findings The section ‘Havel and the Imperative to “Live in Truth”: Dissent and Green Politics’ explores Havel’s thought with a particular emphasis on his ethicised notion of political action and critique (‘living in truth’) and his focus on the centrality of dissent (both intellectually and in practice) as central to political critique and action. The section ‘MacIntyre as a Green Thinker: Vulnerability in Political and Moral Theory’ offers an overview of MacIntyre interpreted as a putative green thinker, with a particular emphasis on his ideas of dependence and vulnerability. The Conclusion attempts to draw some common themes together from both thinkers in terms of what they have to offer contemporary green political thought. Research limitations/implications What is presented here is introductory, ground clearing and therefore necessarily suggestive (as well as under-developed). That is, it is the start of a new area of exploration rather than an analysis based on any exhaustive and comprehensive knowledge of both thinkers. Practical implications This chapter offers some initial lines of exploration for scholars interested in the overlap between green thinking and the work of Havel and MacIntyre. Originality/value This is the first exploration of the connections between the works of Havel and MacIntyre and green political theory.