CO Oxidation Catalysed by Pd-based Bimetallic Nanoalloys

Density functional theory based global geometry optimization has been used to demonstrate the crucial influence of the geometry of the catalytic cluster on the energy barriers for the CO oxidation reaction over Pd-based bimetallic nanoalloys. We show that dramatic geometry change between the reaction intermediates can lead to very high energy barriers and thus be prohibitive for the whole process. This introduces challenges for both the design of new catalysts, and theoretical methods employed. On the theory side, a careful choice of geometric configurations of all reaction intermediates is crucial for an adequate description of a possible reaction path. From the point of view of the catalyst design, the cluster geometry can be controlled by adjusting the level of interaction between the cluster and the dopant metal, as well as between the adsorbate molecules and the catalyst cluster by mixing different metals in a single nanoalloy particle. We show that substitution of a Pd atom in the Pd$_{5}$ cluster with a single Ag atom to form Pd$_{4}$Ag$_{1}$ leads to a potential improvement of the catalytic properties of the cluster for the CO oxidation reaction. On the other hand, a single Au atom does not enhance the properties of the catalyst, which is attributed to a weaker hybridization between the cluster's constituent metals and the adsorbate molecules. Such flexibility of properties of bimetallic nanoalloy clusters illustrates the possibility of fine-tuning, which might be used for design of novel efficient catalytic materials.Comment: 12 pages, 8 figure

The effectiveness of employment vouchers : a simple approach.

This paper explores the optimal design of subsidies for hiring unemployed workers (?employment vouchers? for short) in the context of a dynamic model of the labor market. Focusing on the short-term and long-term effects of the vouchers on employment and unemployment, the analysis shows how the optimal policy depends on the rates of hiring and firing, and on the problems of displacement and deadweight. It also examines the roles of the government budget constraint and of the level of unemployment benefits in optimal policy design. We calibrate the model and evaluate the effectiveness of employment vouchers in reducing unemployment for a wide range of feasible parameters.Arbeitsmarkttheorie; Subvention; Personalbeschaffung; Haushaltsdefizit; Theorie;Employment policy , unemployment benefits , government budget constraint;

Expanding the welfare system : a proposal for reform.

The proposal involves the establishment of ?welfare accounts? for every person in a country. There are to be four accounts: a retirement account (covering pensions), an unemployment account (covering unemployment support), a human capital account (covering education and training), and a health account (covering insurance against sickness and disability). Instead of the current welfare state systems - where welfare services are financed predominantly out of general taxes - people would make ongoing, mandatory contributions to each of these welfare accounts. The balances in these accounts would cover people?s major welfare needs. The government is to set mandatory minimum contribution rates and maximum withdrawal rates from the accounts. The government is to have two budgetary systems: one in which non-welfare expenditures are financed through the existing array of taxes, and another system in which the public-sector expenditures on welfare services are financed through payments from people?s welfare accounts. The government would be able to redistribute income across people?s welfare accounts, but these redistributions would be constrained to be of the balanced-budget variety: total (economy-wide) taxes on each of the welfare accounts would be equal to total transfers into each of accounts. The public and private sectors would provide welfare services on an equal footing, setting prices for these services and competing with one another for the custom of the welfare account holders. We argue that moving from the current welfare state systems to a welfare account system may be expected to play a substantial role in reducing unemployment, encouraging labour force participation, promoting skills, reducing governments? budgetary pressures, cushioning people against economic risks, ensuring efficient provision of health and education services, providing social safety nets and redistributing incomes more efficiently.Sozialstaat; Reform; Einkommensumverteilung; Theorie;Welfare state , redistribution , social insurance , unemployment , health , education and training , pensions , sickness and disability ,;

How Should We Prioritise Incident Management Deployment?

With perpetual strains on resources and traffic increasing at a steady rate, transport agencies need to evaluate the road network and make informed decisions to determine which roads have the greatest risk of adverse impacts and therefore identify the roads that have the greatest case for intervention. This is especially the case for Intelligent Transport Systems (ITS) and in particular incident management services where decision-making techniques are immature relative to conventional road engineering. This problem is compounded by the fact that common evaluation tools are insufficient for ITS applications. Historical information for ITS impacts is not always readily available, impacts are not transferable and impacts are incremental to the individual user. For these reasons, a new network evaluation framework is presented in this paper for incident management deployment. The framework aims to analyse the road network and prioritise roads with respect to two factors: the historical risk associated with incidents; and the cost effectiveness of implementation. To assess the historical risk, the framework initially converts social, economic and environmental impacts to a common monetary base, enabling the addition of the incident impacts. The economic impact values must be treated as relative values of measurement, not absolute costs. The second part of the framework assesses the historical risk, taking into account both the consequence of an event, measured in economic terms described above, and the probability of an event occurring based on historical information. The third uses a cost-effective ratio comparing the reduced impacts with the project costs. The economic risk analysis presented in Figure 1 below integrates safety, reliability and environmental impacts, providing an integrated decision-making tool for proactive ITS deployment decision-making

Reflections on culture, change, and service in educational leadership

Educating a child is an overwhelming job that is impossible to do alone. School leaders must develop and nurture a well-articulated vision of success, demonstrate outstanding collaboration with all stakeholders, and model heroically ethical behavior to students and staff. School leaders use reflective practice to become change agents and to create a culture of learning for students and staff

The Effects of Respiratory Muscle Warm-up on Exercise Performance and Pulmonary Functions

Effect of a Specific Respiratory Warm-up on Run Performance, Pulmonary Functions, and Rating of Perceived Breathing The purpose of this study was to evaluate the effect of a respiratory warm-up for five minutes using an inspiratory/expiratory (IEC) device on pulmonary function (PFT) (FVC, FEV©û, FEF 25-75%, PEF), rate of perceived exertional (RPE) breathing, and performance time [300 yard shuttle run (300y) and 1.5 mile run (1.5m)] in asthmatics and non-asthmatics. Ten non-asthmatics males (22.6¡¾7.4 years) participated in phase I, twenty non-asthmatic males (24.2¡¾9.8 years) in phase II, and five asthmatics (20.8¡¾3.2 years) in phase III of this study. The Phase I pilot study examined three breathing warm-up (inspiratory only, expiratory only, and combined IEC). Results suggest the IEC produced the most favorable responses (greatest system stress, highest recovery data). In phase II and III, subjects performed initial resting PFT (asthmatics performed an additional five-minute post medication resting PFT), followed by five-minutes of a no-warm-up controlled condition (CC) or five-minutes of IEC. After completion of the CC or the IEC, subjects rested for five-minutes and then performed either a 300y or a 1.5m for time. After the runs, subjects performed one-minute recovery intervals of PF and RPE up to 15-minutes as well as five-minute intervals of PFT up to 15-minutes. Paired sample t-tests were calculated to compare CC to IEC across the two runs with statistical significance for these correlations set at p ¡Â 0.05*. The results indicated that non-asthmatics benefited from the IEC and improved performance by 3.2% (average of 25 seconds) in the 1.5m over the CC [M=13.1075 v. 12.6830, SD=2.19429 v. 1.85474, p= 0.044*]. Asthmatics increased their FEV©û at five-minutes of recovery after the IEC verses the CC for the 1.5m [M=3.3120 v. 3.4280, SD=0.51339 v. 0.54929, p= 0.019*]. The results suggest that a respiratory warm-up could be beneficial by improved performance and increased pulmonary functions to asthmatics and non-asthmatics alike