Efficient superfluorescent light sources with broad bandwidth

We demonstrate various efficient broad-band light sources at ~1µm wavelength with a 3dB bandwidth of up to 65nm at 108mW output power, based on rare-earth doped silica fibers and a simple adjustable spectral filter

THE CAPSTONE EXPERIENCE COURSE IN AGRICULTURAL CURRICULUM

Capstone courses are being developed in colleges of agriculture in response to demands from agribusiness firms, students, and other university stakeholders. With data from a faculty survey, the factors affecting the success of capstone courses in agricultural economics as well as other agricultural disciplines are identified.Teaching/Communication/Extension/Profession,

Electrically detected interferometry of Majorana fermions in a topological insulator

We show how a chiral Dirac fermion (a massless electron or hole) can be converted into a pair of neutral chiral Majorana fermions (a particle equal to its own antiparticle). These two types of fermions exist on the metallic surface of a topological insulator, respectively, at a magnetic domain wall and at a magnet-superconductor interface. Interferometry of Majorana fermions is a key operation in topological quantum computation, but the detection is problematic since these particles have no charge. The Dirac-Majorana converter enables electrical detection of the interferometric signal.Comment: 4 pages, 2 figure

On Making Good Games - Using Player Virtue Ethics and Gameplay Design Patterns to Identify Generally Desirable Gameplay Features

This paper uses a framework of player virtues to perform a theoretical exploration of what is required to make a game good. The choice of player virtues is based upon the view that games can be seen as implements, and that these are good if they support an intended use, and the intended use of games is to support people to be good players. A collection of gameplay design patterns, identified through their relation to the virtues, is presented to provide specific starting points for considering design options for this type of good games. 24 patterns are identified supporting the virtues, including RISK/REWARD, DYNAMIC ALLIANCES, GAME MASTERS, and PLAYER DECIDED RESULTS, as are 7 countering three or more virtues, including ANALYSIS PARALYSIS, EARLY ELIMINATION, and GRINDING. The paper concludes by identifying limitations of the approach as well as by showing how it can be applied using other views of what are preferable features in games

Towards a practical approach for self-consistent large amplitude collective motion

We investigate the use of an operatorial basis in a self-consistent theory of large amplitude collective motion. For the example of the pairing-plus-quadrupole model, which has been studied previously at equilibrium, we show that a small set of carefully chosen state-dependent basis operators is sufficient to approximate the exact solution of the problem accuratly. This approximation is used to study the interplay of quadrupole and pairing degrees of freedom along the collective path for realistic examples of nuclei. We show how this leads to a viable calculational scheme for studying nuclear structure, and discuss the surprising role of pairing collapse.Comment: 19 pages, 8 figures Revised version To be published in Phys. Rev.

Are the Mediterranean countries competitive in fresh fruit and vegetable exports?

The Barcelona Agreement was signed in 1995, setting forth a structure with bilateral agreements between the EU and twelve Mediterranean countries. The agreement also foresaw the creation of a free trade area in the Euro-Mediterranean region by 2010. For many of the countries surrounding the Mediterranean sea, fruit and vegetables are very important products. In light of the increasing trade liberalization and thus increasing competition between countries, this paper aims to investigate further the competitiveness of Mediterranean countries with respect to fresh fruit and vegetables. The results generally show that the competitiveness of the investigated countries has deteriorated over the period. In only two cases, there is an increase in competitiveness.International Relations/Trade,

Revanchist Russia? Russian perceptions of Belarusian and Ukrainian sovereignty, 1990-2008

The theme of this thesis concerns post-Soviet Russian foreign policy perceptions of Belarusian and Ukrainian sovereignty between 1990 and 2008. In the thesis I argue that Russian perceptions became increasingly revanchist in nature during this period, and that we may distinguish between two different types of revanchism, the consequences of which for Belarusian and Ukrainian sovereignty are quite different. I argue that all Russian perceptions of international affairs are constituted by perceptions of Russia. Thus, perceptions of Belarusian and Ukrainian sovereignty may be divided into three categories, or paradigms, each of which centres on a specific concept that legitimises the existence of Russia, and determines how Belarus and Ukraine are viewed. The three central concepts are the concepts of Law, Power, and Nation, respectively. In the introduction, I outline these paradigms, both in abstract terms and in relation to Russian foreign policy in general, as well as Russian foreign policy towards Belarus and Ukraine. Subsequently, I present my methodology and my literature review, together with a discussion of the theoretical assumptions, which provide the foundation for my argument. Then, I briefly outline Russian foreign policy making during the period relevant for my thesis, before the four main chapters of my thesis outline in roughly chronological fashion how the relative significance of the three paradigms has changed over time. Overall, I find that whereas the paradigm of Power has generally dominated perceptions, the paradigm of Law has gradually lost influence, whereas the influence of the paradigm of Nation has gradually increased. Since I define both the paradigm of Power and the paradigm of Nation as “revanchist,” I conclude that Russian perceptions of Belarusian and Ukrainian sovereignty between 1990 and 2008 gradually became more revanchist in nature

Comment on ``Two Time Scales and Violation of the Fluctuation-Dissipation Theorem in a Finite Dimensional Model for Structural Glasses''

In cond-mat/0002074 Ricci-Tersenghi et al. find two linear regimes in the fluctuation-dissipation relation between density-density correlations and associated responses of the Frustrated Ising Lattice Gas. Here we show that this result does not seem to correspond to the equilibrium quantities of the model, by measuring the overlap distribution P(q) of the density and comparing the FDR expected on the ground of the P(q) with the one measured in the off-equilibrium experiments.Comment: RevTeX, 1 page, 2 eps figures, Comment on F. Ricci-Tersenghi et al., Phys. Rev. Lett. 84, 4473 (2000

Lifetime quenching in Yb doped fibres

We have discovered that in ytterbium-doped silica fibres the excited state lifetime of a fraction of the Yb ions can be quenched to a very small value, leading to a strong unbleachable loss. This unexpected behaviour seems to be caused by some, yet unidentified, impurity or structural defect. It is of considerable relevance for various Yb doped lasers and-amplifiers including Er:Yb codoped fibres as used in telecommunication amplifiers although it should also be emphasized that fibres can be produced that are free from the quenching effect