6,370 research outputs found
Pumped current and voltage for an adiabatic quantum pump
We consider adiabatic pumping of electrons through a quantum dot. There are
two ways to operate the pump: to create a dc current or to create a
dc voltage . We demonstrate that, for very slow pumping,
and are not simply related via the dc conductance as . For the case of a chaotic quantum dot, we consider the statistical
distribution of . Results are presented for the limiting
cases of a dot with single channel and with multichannel point contacts.Comment: 6 pages, 4 figure
Rectification of displacement currents in an adiabatic electron pump
Rectification of ac displacement currents generated by periodic variation of
two independent gate voltages of a quantum dot can lead to a dc voltage linear
in the frequency. The presence of this rectified displacement current could
account for the magnetic field symmetry observed in a recent measurement on an
adiabatic quantum electron pump by Switkes et al. [Science 283, 1905 (1999)].Comment: 2 pages, RevTeX; 1 figur
Welfarism vs. extra-welfarism
'Extra-welfarism' has received some attention in health economics, yet there is little consensus on what distinguishes it from more conventional 'welfarist economics'. In this paper, we seek to identify the characteristics of each in order to make a systematic comparison of the ways in which they evaluate alternative social states. The focus, though this is not intended to be exclusive, is on health. Specifically, we highlight four areas in which the two schools differ: (i) the outcomes considered relevant in an evaluation; (ii) the sources of valuation of the relevant outcomes; (iii) the basis of weighting of relevant outcomes and (iv) interpersonal comparisons. We conclude that these differences are substantive. (C) 2007 Elsevier B.V. All rights reserved
Towards adaptive management: examining the strategies of policy entrepreneurs in Dutch water management
The growing awareness of the complexities and uncertainties in water management has put into question the existing paradigms in this field. Increasingly more flexible, integrated, and adaptive policies are promoted. In this context, the understanding of how to effect policy change is becoming more important. This article analyzes policy making at the micro level, focusing on the behavior of policy entrepreneurs, which we understand here as risk-taking bureaucrats who seek to change policy and are involved throughout the policy-change process. Policy entrepreneurs have received a certain level of attention in the adaptive co-management literature and the policy sciences in past decades. Yet, the understanding of the actions they can take to facilitate policy change remains limited. This study addresses this gap in focusing on the strategies that policy entrepreneurs employ in their efforts to effect policy change. The article draws on both theoretical exploration and in-depth field research on water management in the Netherlands, which included a series of semi-structured interviews and a focus group with policy entrepreneurs. We conclude that policy entrepreneurs employ four types of strategies: (1) attention and support-seeking strategies, to demonstrate the significance of a problem and to convince a wide range of participants about their preferred policy; (2) linking strategies, to link with other parties, projects, ideas, and policy games; (3) relational management strategies, to manage the relational factor in policy-change trajectories; and finally, (4) arena strategies, to influence the time and place wherein decisions are made. Our study suggests that by employing these strategies when the "time is right," the development of policy streams and consequently their coupling can, to some extent, be influenced and steered. In other words, policy entrepreneurs can, to a degree, prepare for a window of opportunity and hence direct policy change
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