Hysteretic ac losses in a superconductor strip between flat magnetic shields

Hysteretic ac losses in a thin, current-carrying superconductor strip located between two flat magnetic shields of infinite permeability are calculated using Bean's model of the critical state. For the shields oriented parallel to the plane of the strip, penetration of the self-induced magnetic field is enhanced, and the current dependence of the ac loss resembles that in an isolated superconductor slab, whereas for the shields oriented perpendicular to the plane of the strip, penetration of the self-induced magnetic field is impaired, and the current dependence of the ac loss is similar to that in a superconductor strip flanked by two parallel superconducting shields. Thus, hysteretic ac losses can strongly augment or, respectively, wane when the shields approach the strip.Comment: 9 pages, 5 figures, submitted to PR

The role of fixed cost in international environmental negotiations.

We investigate the relative efficiency of an agreement based on a uniform standard without transfers and one based on differentiated standards with transfers when strictly identical countries deal with transboundary pollution. We especially ask what role fixed cost plays. Two approaches are examined: the Nash bargaining solution, involving two countries, and the coalition formation framework, involving numerous countries and emphasizing self-enforcing agreements. In the former, in terms of welfare, strictly identical countries may wish to reduce their emissions in a non-uniform way under the differentiated agreement. For this result to hold, the fixed cost of investment in abatement technology must be sufficiently high. The nature of the threat point of negotiations, however, also plays a crucial role. As concerns global abatement, the two countries abate more under the uniform agreement than under the differentiated one. In terms of coalition formation when numerous countries are involved, a grand coalition could emerge under a differentiated agreement.bargaining; standards; costs; Transboundary pollution;

New Zealand’s Social Assistance System: Financial Incentives to Work

This paper is a stock take of the financial incentives to work present in New Zealand’s social assistance system. The purpose of this paper is to provide a basis for research on problems facing the social assistance system and dilemmas that would be likely to arise when considering potential initiatives to address such problems. The current financial incentives to work contained in the social assistance system reflect efforts to tailor different financial incentives to different groups in the population. No single structure of financial incentives is appropriate for all people and at all times. It is therefore necessary from time to time to consider whether existing financial incentives continue to meet government objectives, such as encouraging work among different groups in the population. Improving the structure of financial incentives, however, defies simple solutions and requires trade-offs between competing and conflicting objectives to be made. In order to set the scene for later discussion, this paper begins with a brief description of the evolution of New Zealand’s social assistance system. This paper then moves on to discuss the financial returns from social assistance programmes and the distribution of the financial disincentives to work present in the current social assistance system. A number of further considerations are then discussed, particularly accommodation and childcare costs and the length of time that people tend to spend on social welfare benefits. This paper then considers the need for trade-offs between policy outcomes when developing policy initiatives to improve financial incentives to work before presenting a summary of its main findings. Appendixes to this paper describe the programmes that make up New Zealand’s three-tier social assistance system, key features of the personal income tax scale, a method for calculating Effective Marginal Tax Rates (EMTRs), and TaxMod and the Household Economic Survey (HES).Social Security, Social Assistance

New Zealand’s Family Assistance Tax Credits: Evolution and Operation

The Family Assistance Tax Credits provide income-tested (and in some cases work-tested) financial assistance for families with financially dependent children who are living at home. This paper describes the evolution and operation of the Family Assistance programmes. This description clarifies how these programmes have evolved and operate and provides a basis for future research. The topics discussed in this paper are as follows: the programmes that preceded the Family Assistance programmes; the changing levels of assistance, abatement regimes and eligibility criteria for each of the Family Assistance programmes; the roles of the Inland Revenue Department and the Ministry of Social Development in administering the Family Assistance programmes; the definitions of income in operation in the social welfare and tax systems, the calculation of the taxation and abatement of social welfare benefits and the calculation of Family Assistance entitlement; the calculation of the impact of the Family Assistance programmes on the financial rewards from work; and the fiscal cost to the government of the social assistance system in general and the Family Assistance programmes in particular.Social security, social assistance, refundable tax rebates

EFFICIENCY AND EQUITY ASPECTS OF NONPOINT SOURCE POLLUTION CONTROLS

Environmental Economics and Policy,

SIRT1 selectively exerts the metabolic protective effects of hepatocyte nicotinamide phosphoribosyltransferase

Calorie restriction abates aging and cardiometabolic disease by activating metabolic signaling pathways, including nicotinamide adenine dinucleotide (NA

Tradeable Emission Permits in Oligopoly

The paper considers an oligopolistic industry in which pollution is a by-product of production. Firms are assumed to have emission permits that restrict the amount that they pollute. These permits are assumed to be tradeable and the paper discusses a structure in which the same set of firms operates both in the product market as well as in the pollution permits market. The paper demonstrates that in such a structure allowing trade in emission permits is not necessarily beneficial. In particular it may lead to the choice of inferior production and abatement technologies, it may lead to a market equilibrium with lower output rates and higher prices and it may result in a shift of production from a low cost to a high cost firm.pollution control;oligopoly;trade;emission permit

Cloaking of Arbitrarily-Shaped Objects with Homogeneous Coatings

We present a theory for the cloaking of arbitrarily-shaped objects and demonstrate electromagnetic scattering-cancellation through designed homogeneous coatings. First, in the small-particle limit, we expand the dipole moment of a coated object in terms of its resonant modes. By zeroing the numerator of the resulting rational function, we accurately predict the permittivity values of the coating layer that abates the total scattered power. Then, we extend the applicability of the method beyond the small-particle limit, deriving the radiation corrections of the scattering-cancellation permittivity within a perturbation approach. Our method permits the design of invisibility cloaks for irregularly-shaped devices such as complex sensors and detectors