4,772 research outputs found
Manejo da pesca e a interdisciplinaridade
The present state of world fisheries shows that fishery management is unable to sustain yields andresolve the conflicts between conservation and development. Fishery science recognized the importance of multi-disciplinarity long ago, particularly in subjects like stock recruitment, abundance fluctuations and trophic relationships. In order to attain a better level of understanding and efficiency, fishery management needs to incorporate and integrate an interdisciplinary approach, where important aspects as sociology and economics of the different actors and stakeholders must be weighted and considered
Geometrical statistics of the vorticity vector and the strain rate tensor in rotating turbulence
We report results on the geometrical statistics of the vorticity vector
obtained from experiments in electromagnetically forced rotating turbulence. A
range of rotation rates is considered, from non-rotating to rapidly
rotating turbulence with a maximum background rotation rate of rad/s
(with Rossby number much smaller than unity). Typically, in our experiments
. The measurement volume is located in the
centre of the fluid container above the bottom boundary layer, where the
turbulent flow can be considered locally statistically isotropic and
horizontally homogeneous for the non-rotating case, see van Bokhoven et al.,
Phys. Fluids 21, 096601 (2009). Based on the full set of velocity derivatives,
measured in a Lagrangian way by 3D Particle Tracking Velocimetry, we have been
able to quantify statistically the effect of system rotation on several flow
properties. The experimental results show how the turbulence evolves from
almost isotropic 3D turbulence ( rad/s) to quasi-2D
turbulence ( rad/s) and how this is reflected by several
statistical quantities. In particular, we have studied the orientation of the
vorticity vector with respect to the three eigenvectors of the local strain
rate tensor and with respect to the vortex stretching vector. Additionally, we
have quantified the role of system rotation on the self-amplification terms of
the enstrophy and strain rate equations and the direct contribution of the
background rotation on these evolution equations. The main effect is the strong
reduction of extreme events and related (strong) reduction of the skewness of
PDFs of several quantities such as, for example, the intermediate eigenvalue of
the strain rate tensor and the enstrophy self-amplification term.Comment: 17 pages, 6 figures, 3 table
Improved Fine Particles Monitoring in Smart Cities by Means of Advanced Data Concentrator
Traffic reduction and air-quality improvement are among the main goals of several projects worldwide. This article presents a fine particle monitoring based on heterogeneous air quality mobile sensors and an advanced data concentrator (AdDC), so that the level of pollution in the urban area, where few accurate fixed measurement stations are present, can be assessed with better accuracy. Some urban buses are used to carry low-cost sensors, thus implementing a mobile sensor network and increasing the time and space resolution of air quality information. The data obtained by these low-cost sensors are significantly affected by uncertainties, also due to atmospheric factors, such as humidity. The proposed AdDC processes all the obtained measurements and exploits the information obtained by the accurate fixed stations to improve the accuracy of the low-cost mobile sensors. In particular, a new compensation methodology, specifically targeted to the fine particles monitoring, is proposed. The monitoring of relative humidity is added, with the relevant on-the-fly calibration, so that the measured values can be used to correct the effects of humidity on PM2.5 sensors. The validity of the proposed system is proven by means of simulations performed on an appropriate set up
Classical bridge functions in classical and quantum plasma liquids
Bridge functions, the missing link in the exact description of strong
correlations, are indirectly extracted from specially designed molecular
dynamics simulations of classical one-component plasma liquids and accurately
parameterized. Their incorporation into an advanced integral equation theory
description of Yukawa one-component plasma liquids and a novel dielectric
formalism scheme for quantum one-component plasma liquids leads to an
unprecedented agreement with available molecular dynamics simulations and new
ab initio path integral Monte Carlo simulations, respectively.Comment: 6 pages, 4 figures, 2 table
Testing the isomorph invariance of the bridge functions of Yukawa one-component plasmas. I. Intermediate and long range
It has been recently conjectured that bridge functions remain nearly
invariant along phase diagram lines of constant excess entropy for the broad
class of R-simple liquids. To test this hypothesis, the bridge functions of
Yukawa systems are computed outside the correlation void with the
Ornstein-Zernike inversion method and structural input from ultra-accurate
molecular dynamics simulations. The effect of statistical, grid, finite-size,
tail and isomorphic errors is quantified. Uncertainty propagation analysis is
complemented with a detailed investigation of the sensitivity of the bridge
function to periodic and aperiodic multiplicative perturbations in the radial
distribution function. In the long and intermediate range, bridge functions are
demonstrated to be approximately isomorph invariant.Comment: 22 pages; 12 figure
In whose name? : political representation and civil organisations in Brazil
There is now considerable evidence that civil organisations have become de facto and de jure representatives
of particular segments of the population and interests in the design, implementation, and monitoring of
public policy. This paper explores two questions that are becoming increasingly important in the debate
on the role of “civil society” in contemporary democracy: Who do civil organisations represent when they
act as representatives in the polity; and, in what terms is this representation constructed? The role of civil
organisations in political representation has received little or no attention in the research agendas on the
reconfiguration of representation or on the democratising of democracy. Furthermore, there are no wellestablished
theoretical models beyond the classic electoral or membership ones which set out how civil
organisations could establish their representativeness. The vast majority of civil organisations in middleand
low-income countries, however, are not membership based and few make use of electoral procedures
to authorise a mandate or establish accountability.
This paper examines which organisations define themselves as political representatives and the forms
of representation they are constructing. It also explores some of the possible consequences of different
forms of representation for democracy. The paper draws on findings of a survey of civil organisations –
that is, neighbourhood or community associations, membership organisations, NGOs, and coordinators
of networks of these organisations – in the city of São Paulo, Brazil. We find that organisations that
publicly claim to be representatives of particular publics in fact do engage in extensive representation
activities; and, that the dynamics of representation among civil organisations are closely related to those of
traditional political channels of representation. Furthermore, we find that the congruency arguments civil
organisations make publicly to support their representativeness are crystallising around a small number of
notions of representation. The most common are mediation, proximity, and services. The least common
are identity, electoral, and membership
The 2009 EU Industrial R&D Investment SCOREBOARD
The 2009 "EU Industrial R&D Investment Scoreboard" (the Scoreboard) presents information on the top 1000 EU companies and the top 1000 non-EU companies ranked by their investments in research and development (R&D).
The Scoreboard data are drawn from the latest available companies' accounts, i.e. the fiscal year 2008 . In the last part of this reporting period, the world economy entered into a strong financial and economic crisis that affected companies throughout the world. Some of the effects of the crisis are already reflected in these company results, namely on indicators such as sales, operating profits and market capitalisation. However, the full effects of the crisis, especially on R&D, tend to lag and are not yet captured in this Scoreboard.JRC.J.3-Knowledge for Growt
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