Nanometers-thick self-organized Fe stripes: bridging the gap between surfaces and magnetic materials

We have fabricated 5nm-high Fe(110) stripes by self-organized (SO) growth on a slightly vicinal R(110)/Al2O3(11-20) surface, with R=Mo, W. Remanence, coercivity and domain patterns were observed at room temperature (RT). This contrasts with conventional SO epitaxial systems, that are superparamagnetic or even non-magnetic at RT due to their flatness. Our process should help to overcome superparamagnetism without compromise on the lateral size if SO systems are ever to be used in applications

Humanising complex projects through design thinking and its effects

The last decades of research in project studies show us that humans, rather than technologies, software or mathematical models, shape project success. This is simultaneously fascinating and problematic since, while technologies, software or mathematical models are relatively predictable and straightforward, humans are far more complex, with extremely intricate links between motivations and emotions. This consideration is particularly true in complex projects where a plethora of diverse stakeholders have very different emotions and motivations toward the same project. To address this challenge, this essay proposes using design thinking principles, tools, and techniques to "humanise" complex projects. By bringing together stakeholders, including non-market stakeholders such as local communities, with diverse goals and interests and aligning them with a common purpose, design thinking can help to shape, plan, and deliver successful complex projects. While design thinking is commonly discussed in innovation studies, this essay aims to encourage its investigation and discussion in project studies

Atributo diagnóstico do solo: saturação de bases nas propriedades em transição para o sistema agroecológico, Alto Paraíso, Rondônia.

O município de Alto Paraíso apresenta agricultura familiar expressiva. Estes agricultores se associaram em uma Associação que está ligada a uma cooperativa que trabalha com café agroecológico entre outros produtos. O objetivo deste trabalho foi estudar a saturação de bases do solo em Latossolo Vermelho Amarelo nas propriedades rurais de agricultores familiares que fazem parte no município e o tipo de manejo do solo nas propriedades em transição para a agroecologia. A pesquisa teve como método: trabalho de campo com auxilio de entrevistas e aplicação de formulário de campo modificado da Empresa Brasileira de Pesquisa Agropecuária ? EMBRAPA-RO e análise de dados de solo. Concluiu-se que estas propriedades encontram-se em processo de transição de uma agricultura convencional e migratória para o sistema de uso agroecológico com auxílio dos Sistemas Agroflorestais ? SAF , os solos das propriedades em processo de transição para o modelo agroecológico indicaram um percentual de saturação maior que os solos das que empregam práticas convencionais, práticas de uso e manejo foram modificadas tendo em vista a baixa fertilidade do solo no local que mostrou a necessidade de adubação e calagem

Physical properties of the jet from DG Tauri on sub-arcsecond scales with HST/STIS

We derive the physical properties at the base of the jet from DG Tau both along and across the flow and as a function of velocity. We analysed seven optical spectra of the DG Tau jet, taken with the Hubble Space Telescope Imaging Spectrograph. The spectra were obtained by placing a long-slit parallel to the jet axis and stepping it across the jet width. The resulting position-velocity diagrams in optical forbidden emission lines allowed access to plasma conditions via calculation of emission line ratios. We find at the base of the jet high electron density, $n_e \sim$ 10$^5$, and very low ionisation, $x_e \sim 0.02-0.05$, which combine to give a total density up to $n_H \sim$ 3 10$^6$. This analysis confirms previous reports of variations in plasma parameters along the jet, (i.e. decrease in density by several orders of magnitude, increase of $x_e$ from 0.05 to a plateau at 0.7 downstream at 2$''$ from the star). Furthermore, a spatial coincidence is revealed between sharp gradients in the total density and supersonic velocity jumps. This strongly suggests that the emission is caused by shock excitation. The position-velocity diagrams indicate the presence of both fast accelerating gas and slower, less collimated material. We derive the mass outflow rate, $\dot{M}_j$, in the blue-shifted lobe in different velocity channels, that contribute to a total of $\dot{M}_j \sim$ 8 $\pm$ 4 10$^{-9}$ M$_\odot$ yr$^{-1}$. We estimate that a symmetric bipolar jet would transport at the low and intermediate velocities probed by rotation measurements, an angular momentum flux of $\dot{L}_j \sim$ 2.9 $\pm$ 1.5 10$^{-6}$ M$_\odot$ yr$^{-1}$ AU km s$^{-1}$. The derived properties of the DG Tau jet are demonstrated to be consistent with magneto-centrifugal theory. However, non-stationary modelling is required in order to explain all of the features revealed at high resolution.Comment: 16 pages, 18 figure

Secular dynamics of a planar model of the Sun-Jupiter-Saturn-Uranus system; effective stability into the light of Kolmogorov and Nekhoroshev theories

We investigate the long-time stability of the Sun-Jupiter-Saturn-Uranus system by considering a planar secular model, that can be regarded as a major refinement of the approach first introduced by Lagrange. Indeed, concerning the planetary orbital revolutions, we improve the classical circular approximation by replacing it with a solution that is invariant up to order two in the masses; therefore, we investigate the stability of the secular system for rather small values of the eccentricities. First, we explicitly construct a Kolmogorov normal form, so as to find an invariant KAM torus which approximates very well the secular orbits. Finally, we adapt the approach that is at basis of the analytic part of the Nekhoroshev's theorem, so as to show that there is a neighborhood of that torus for which the estimated stability time is larger than the lifetime of the Solar System. The size of such a neighborhood, compared with the uncertainties of the astronomical observations, is about ten times smaller.Comment: 31 pages, 2 figures. arXiv admin note: text overlap with arXiv:1010.260