Long-range triplet proximity effect in multiply connected ferromagnet-superconductor hybrids

Applying the linearized Usadel equations, we consider the nucleation of superconductivity in multiply connected mesoscopic superconductor/ferromagnet (S/F) hybrids such as a thin superconducting ring on a ferromagnet with a uniform in-plane magnetization M and a spin-active S/F interface. We demonstrate that the exchange field in F provokes a switching between superconducting states with different vorticities which may increase the critical temperature ( Tc ) of the superconductor in a magnetic field. We study the interplay between oscillations in Tc due to the Little--Parks effect and oscillations in Tc induced by the exchange field. Furthermore, we analyse the influence of long-range spin-triplet correlations on the switching between different vorticities.Comment: 11 pages, 7 figure

Technological agglomeration and the emergence of clusters and networks in nanotechnology

Based on the analysis of two clusters in nanotechnologies (MESA+ in the Netherlands and Minatec in Grenoble in France), the paper examines the emergence and effects of technological agglomeration. The social and technical arrangements of a regional centre for nanotechnology both enable and constrain the ongoing activities and research lines that can be followed. Technology platforms and their co-location are a pre-requisite for nanotechnology research and agglomeration of such platforms are both a means and outcome for institutional entrepreneurs to mobilise resources, build networks and construct regional centres of excellence in nanotechnology. Technological agglomeration shapes the networks that evolve and leads to the convergence of scientific disciplines.TECHNOLOGICAL AGGLOMERATION;TECHNOLOGY PLATFORM;CLUSTER;DISTRICT; CONVERGING TECHNOLOGY;MULTILEVEL ACTIVITIES

The role of regional institutional entrepreneurs in the emergence of clusters in nanotechnologies

In the case of new technologies like nanotechnology, institutional entrepreneurs appear who have to act at different levels (organizational, regional, national) at the same time. We reconstruct, in some detail, the history of two cases, in Grenoble and in Twente/Netherlands. An intriguing finding is that institutional entrepreneurs build their environment before changing their institution. They first mobilize European support to convince local and national levels before actual cluster building occurs. Only later will there be reactions against any de-institutionalisation caused at the base location. The Dutch case shows another notable finding: when mobilizing support the entrepreneur will have to agree to further conditions, and then ends up in a different situation (a broad national consortium) than originally envisaged (the final cluster involved a collaboration of Twente with two other centres). In general, an institutional entrepreneur attempts to create momentum, and when this is achieved, he has to follow rather than lead it.INSTITUTIONAL ENTREPRENEUR; DEINSTITUTIONALISATION; CLUSTER; LOCATION; EMERGING TECHNOLOGIES; PROMISE; NANOTECHNOLOGY

The expected background spectrum in NaI dark matter detectors and the DAMA result

Detailed Monte Carlo simulations of the expected radioactive background rates and spectra in NaI crystals are presented. The obtained spectra are then compared to those measured in the DAMA/NaI and DAMA/LIBRA experiments. The simulations can be made consistent with the measured DAMA spectrum only by assuming higher than reported concentrations of some isotopes and even so leave very little room for the dark matter signal. We conclude that any interpretation of the annual modulation of the event rate observed by DAMA as a dark matter signal, should include full consideration of the background spectrum. This would significantly restrict the range of dark matter models capable of explaining the modulation effect.Comment: 17 pages, 6 figure

On the structure of subsets of an orderable group with some small doubling properties

The aim of this paper is to present a complete description of the structure of subsets S of an orderable group G satisfying |S^2| = 3|S|-2 and is non-abelian

Theoretical backgrounds of durability analysis by normalized equivalent stress functionals

Generalized durability diagrams and their properties are considered for a material under a multiaxial loading given by an arbitrary function of time. Material strength and durability under such loading are described in terms of durability, safety factor and normalized equivalent stress. Relations between these functionals are analysed. We discuss some material properties including time and load stability, self-degradation (ageing), and monotonic damaging. Phenomenological strength conditions are presented in terms of the normalized equivalent stress. It is shown that the damage based durability analysis is reduced to a particular case of such strength conditions. Examples of the reduction are presented for some known durability models. The approach is applicable to the strength and durability description at creep and impact loading and their combination

Equilibrium Configuration of Black Holes and the Inverse Scattering Method

The inverse scattering method is applied to the investigation of the equilibrium configuration of black holes. A study of the boundary problem corresponding to this configuration shows that any axially symmetric, stationary solution of the Einstein equations with disconnected event horizon must belong to the class of Belinskii-Zakharov solutions. Relationships between the angular momenta and angular velocities of black holes are derived.Comment: LaTeX, 14 pages, no figure

Promoting Team-Based Exercise Among African American Breast Cancer Survivors

Physical activity benefits the health and well-being of breast cancer survivors (BCS). Yet, many African American survivors do not routinely exercise and have increased risk of poor outcomes. The purpose of this mixed-method study was to identify motivational factors compelling African American BCS to participate in a 14-week team walking program and to intend to continue exercise after the intervention concluded. Focus groups were held with participants (n = 12) before and after training. Content analysis discovered themes before the intervention: Not wanting to go at it alone, exercise not a life or treatment priority, cancer treatment affected activity, advocates to exercise, and can exercise really help? Four themes postintervention themes included: In the same boat, changed mind-set, improved weight and activity, and overcoming barriers. Physical data verified improvements. Results suggest that a team-based exercise training program may assist in overcoming a sedentary behavior tendency and subsequently improve health among survivors