Spin polarization and effective mass: a numerical study in disordered two dimensional systems

We numerically study the magnetization of small metallic clusters. The magnetic susceptibility is enhanced for lower electronic densities due to the stronger influence of electron-electron interactions. The magnetic susceptibility enhancement stems mainly from an enhancement of the mass for commensurate fillings, while for non-commensurate fillings its a result of an enhancement of the Land\'e $g$ factor. The relevance to recent experimental measurements is discussed.Comment: 4 pages, 4 figures, accepted for publication in PR

Russell Square: a lifelong resource for teaching and learning

A quarter of a century ago, in 1978, Birkbeck College’s Faculty of Continuing Education (FCE, then the Department for Extra-Mural Studies of the federal University) moved to the offices that it now occupies in numbers 26 and 25 Russell Square. Then, as now, FCE was the one of the largest and most active extra-mural departments of any British university, with an enormous range of courses covering virtually every subject taught in ‘internal’ university departments and many more besides 1. Some of these courses have, from time to time, used Russell Square as a learning resource. Many more staff and students alike have (along with thousands of local workers, tourists and residents) used the square’s gardens for relaxation and recovery, without reflecting on its origins or present significance. This Occasional Paper examines the past and present fabric of Russell Square (‘the Square’) as a resource for teaching and learning. It is a composite narrative assembled by FCE staff whose disciplines range from nature conservation through garden history and architectural history to social policy. It deconstructs the Square as an entity and attempts to decipher some of its ‘meanings’ that provide links between subjects taught within FCE. We hope that it will stimulate discussion about the way this single ‘place’ – our Square - can be ‘seen’ or interpreted in different ways for diverse purposes, and about the way that it can be used as a resource for teaching and learning across disciplines

Effects of Climate Change on Water Resources

Environmental Economics and Policy, Resource /Energy Economics and Policy, Q25, Q54,

DROUGHT AND CLIMATE CHANGE: IMPLICATIONS FOR THE WEST

Environmental Economics and Policy,

The persistence of drought impacts across growing seasons: a dynamic stochastic analysis

Agricultural producers throughout much of the United States experienced one of the most severe droughts in the last 100 years during the years 1999-2006. The prolonged nature of this drought highlights a need to better understand the impacts and management of drought across growing seasons, rather than just within a growing season. Producers express specific concern about the tendency of drought impacts to persist even after drought itself has subsided. The persistence of drought impacts has received limited attention in the economics literature. The objectives of this study are two-fold: 1) to determine whether inter-year dynamics, in the form of agronomic constraints and financial flows, can cause persistence of a drought's impact in years subsequent to the drought, and 2) to determine whether the impact of one year of drought can alter the impact of a subsequent year of drought. A multi-year, dynamic and stochastic decision model is developed in a discrete stochastic programming framework and solved to address the objectives. The structure and parameters of the farm-level model are based on irrigated row crop farms in eastern Oregon, USA. Analysis of the model's solution reveals the following results: 1) the impact of a drought can persist long after the drought subsides, and 2) the impact of one year of drought can alter the impact of a subsequent year of drought. Potential implications for the administration of drought-related assistance are discussed briefly.Drought, preparedness, response, uncertainty, dynamics, discrete stochastic programming, agriculture, irrigation, eastern Oregon, row crops, crop rotation, Crop Production/Industries, Risk and Uncertainty,

Comparison of hydrogen and methane as coolants in regeneratively cooled panels

Comparison of hydrogen and methane as coolants in regeneratively cooled panel

Model reduction, centering, and the Karhunen-Loeve expansion

We propose a new computationally efficient modeling method that captures a given translation symmetry in a system. To obtain a low order approximate system of ODEs, prior to performing a Karhunen Loeve expansion, we process the available data set using a “centering” procedure. This approach has been shown to be efficient in nonlinear scalar wave equations

Prime diagnosticity in short-term repetition priming: Is primed evidence discounted, even when it reliably indicates the correct answer?

The authors conducted 4 repetition priming experiments that manipulated prime duration and prime diagnosticity in a visual forced-choice perceptual identification task. The strength and direction of prime diagnosticity produced marked effects on identification accuracy, but those effects were resistant to subsequent changes of diagnosticity. Participants learned to associate different diagnosticities with primes of different durations but not with primes presented in different colors. Regardless of prime diagnosticity, preference for a primed alternative covaried negatively with prime duration, suggesting that even for diagnostic primes, evidence discounting remains an important factor. A computational model, with the assumption that adaptation to the statistics of the experiment modulates the level of evidence discounting, accounted for these results