320 research outputs found
Risks, alternative knowledge strategies and democratic legitimacy: the conflict over co-incineration of hazardous industrial waste in Portugal.
The decision to incinerate hazardous industrial waste in cement plants (the socalled
‘co-incineration’ process) gave rise to one of the most heated environmental
conflicts ever to take place in Portugal. The bitterest period was between 1997 and
2002, after the government had made a decision. Strong protests by residents,
environmental organizations, opposition parties, and some members of the
scientific community forced the government to backtrack and to seek scientific
legitimacy for the process through scientific expertise. The experts ratified the
government’s decision, stating that the risks involved were socially acceptable.
The conflict persisted over a decade and ended up clearing the way for a more
sustainable method over which there was broad social consensus – a multifunctional
method which makes it possible to treat, recover and regenerate most
wastes. Focusing the analysis on this conflict, this paper has three aims: (1) to
discuss the implications of the fact that expertise was ‘confiscated’ after the
government had committed itself to the decision to implement co-incineration and
by way of a reaction to the atmosphere of tension and protest; (2) to analyse the
uses of the notions of ‘risk’ and ‘uncertainty’ in scientific reports from both
experts and counter-experts’ committees, and their different assumptions about
controllability and criteria for considering certain practices to be sufficiently safe
for the public; and (3) to show how the existence of different technical scientific
and political attitudes (one more closely tied to government and the corporate
interests of the cement plants, the other closer to the environmental values of reuse
and recycling and respect for the risk perception of residents who challenged
the facilities) is closely bound up with problems of democratic legitimacy. This
conflict showed how adopting more sustainable and lower-risk policies implies a
broader view of democratic legitimacy, one which involves both civic movements
and citizens themselves
Limiting nutrients for bean production on contrasting soil types of Lake Victoria Crescent of Uganda
Common bean (Phaseolus vulgaris L.) is one of the most important grain
legumes in East Africa, but its yield has remained below the genetic
potential. Declining soil fertility is among the primary constraints to
bean production in most East African bean producing regions. Often
existing recommendations are generic and inept to guide farm level
decision making on nutrient replenishment. A greenhouse nutrient
omission study was conducted to determine the limiting nutrients in
three soils of Masaka District, commonly cropped to beans:
\u201cLiddugavu\u201d a Phaeozem, \u201cLimyufumyufu\u201d a
Cambisol and \u201cLuyinjayinga\u201d an Umbrisol soil. Nine
treatments; (i) complete nutrient treatment, (ii) N omitted, (iii) P
omitted, (iv) K omitted, (v) Mg omitted, (vi) S omitted, (vii) Ca
omitted, (viii) Micronutrients omitted and (ix) control without
nutrients. Each treatment was randomly assigned to the three soils and
replicated three times using a completely randomised design. Nitrogen,
phosphorus and potassium were limiting nutrients for bean production in
Umbrisol (Luyinjayinja) while in Cambisol (\u2018Limyufumyufu), common
bean production was most limited by soil acidity. The performance
varied with soil types, with beans grown on the Phaeozem registering
greater leaf number and growth, confirming both scientist\u2019s and
local farmer\u2019s knowledge that this soil has greater potential
than the other two soils.Le haricot commun (Phaseolus vulgaris L.) est un des l\ue9gumes
\ue0 grains les plus importants en Afrique de l\u2019Est, mais son
rendement reste toujours en dessous de son potentiel
g\ue9n\ue9tique. La baisse de la fertilit\ue9 du sol est parmi
les contraintes primaires \ue0 la production du haricot dans la
plupart des r\ue9gions productrices de l\u2019Afrique de
l\u2019Est. Le plus souvent, les recommandations sont
g\ue9n\ue9riques et inad\ue9quates pour guider la prise de
d\ue9cision au niveau champ sur le r\ue9approvisionnement en
nutriment. Une \ue9tude sous serre sur l\u2019omission de nutriment
a \ue9t\ue9 conduite pour d\ue9terminer les nutriments limitants
dans les trois sols du district de Masaka, commun\ue9ment
utilis\ue9s pour produire du haricot\ua0: \u201cLiddugavu\u201d
un sol du Phaeozem, \u201cLimyufumyufu\u201d un sol du Cambisol et
\u201cLuyinjayinga\u201d un sol du Umbrisol. Neuf traitements, (i)
traitement complet de nutriments, (ii) N omis, (iii) P omis, (iv) K
omis, (v) Mg omis, (iv) S omis, (vii) Ca omis, (viii) micronutriments
omis et (ix) control sans nutriments. Chacun des traitements a
\ue9t\ue9 al\ue9atoirement distribu\ue9 aux trois types de sols
et r\ue9pliqu\ue9 trois fois dans un dispositif compl\ue8tement
al\ue9atoire. Azote, phosphore, et potassium ont \ue9t\ue9 les
nutriments limitants pour la production du haricot dans Umbrisol
(Luyinjayinja) tandis que dans Cambisol (\u2018Limyufumyufu), la
production du haricoct commun a \ue9t\ue9 limit\ue9e par
l\u2019acidit\ue9 du sol. Les performances varient en fonction des
types de sols, avec le haricot produit sur le Phaeozem comptant plus de
feuilles et de croissance, confirmant \ue0 la fois les connaissances
des scientifiques et des populations locales qui stipulent que le sol a
un potentiel plus \ue9lev\ue9 que les deux autres sols
The large longitudinal spread of solar energetic particles during the January 17, 2010 solar event
We investigate multi-spacecraft observations of the January 17, 2010 solar
energetic particle event. Energetic electrons and protons have been observed
over a remarkable large longitudinal range at the two STEREO spacecraft and
SOHO suggesting a longitudinal spread of nearly 360 degrees at 1AU. The flaring
active region, which was on the backside of the Sun as seen from Earth, was
separated by more than 100 degrees in longitude from the magnetic footpoints of
each of the three spacecraft. The event is characterized by strongly delayed
energetic particle onsets with respect to the flare and only small or no
anisotropies in the intensity measurements at all three locations. The presence
of a coronal shock is evidenced by the observation of a type II radio burst
from the Earth and STEREO B. In order to describe the observations in terms of
particle transport in the interplanetary medium, including perpendicular
diffusion, a 1D model describing the propagation along a magnetic field line
(model 1) (Dr\"oge, 2003) and the 3D propagation model (model 2) by (Dr\"oge et
al., 2010) including perpendicular diffusion in the interplanetary medium have
been applied, respectively. While both models are capable of reproducing the
observations, model 1 requires injection functions at the Sun of several hours.
Model 2, which includes lateral transport in the solar wind, reveals high
values for the ratio of perpendicular to parallel diffusion. Because we do not
find evidence for unusual long injection functions at the Sun we favor a
scenario with strong perpendicular transport in the interplanetary medium as
explanation for the observations.Comment: The final publication is available at http://www.springerlink.co
Molecular velocity auto-correlation of simple liquids observed by NMR MGSE method
The velocity auto-correlation spectra of simple liquids obtained by the NMR
method of modulated gradient spin echo show features in the low frequency range
up to a few kHz, which can be explained reasonably well by a long
time tail decay only for non-polar liquid toluene, while the spectra of polar
liquids, such as ethanol, water and glycerol, are more congruent with the model
of diffusion of particles temporarily trapped in potential wells created by
their neighbors. As the method provides the spectrum averaged over ensemble of
particle trajectories, the initial non-exponential decay of spin echoes is
attributed to a spatial heterogeneity of molecular motion in a bulk of liquid,
reflected in distribution of the echo decays for short trajectories. While at
longer time intervals, and thus with longer trajectories, heterogeneity is
averaged out, giving rise to a spectrum which is explained as a combination of
molecular self-diffusion and eddy diffusion within the vortexes of hydrodynamic
fluctuations.Comment: 8 pages, 6 figur
Update on the correlation of the highest energy cosmic rays with nearby extragalactic matter
Data collected by the Pierre Auger Observatory through 31 August 2007 showed
evidence for anisotropy in the arrival directions of cosmic rays above the
Greisen-Zatsepin-Kuz'min energy threshold, \nobreak{eV}. The
anisotropy was measured by the fraction of arrival directions that are less
than from the position of an active galactic nucleus within 75 Mpc
(using the V\'eron-Cetty and V\'eron catalog). An updated
measurement of this fraction is reported here using the arrival directions of
cosmic rays recorded above the same energy threshold through 31 December 2009.
The number of arrival directions has increased from 27 to 69, allowing a more
precise measurement. The correlating fraction is , compared
with expected for isotropic cosmic rays. This is down from the early
estimate of . The enlarged set of arrival directions is
examined also in relation to other populations of nearby extragalactic objects:
galaxies in the 2 Microns All Sky Survey and active galactic nuclei detected in
hard X-rays by the Swift Burst Alert Telescope. A celestial region around the
position of the radiogalaxy Cen A has the largest excess of arrival directions
relative to isotropic expectations. The 2-point autocorrelation function is
shown for the enlarged set of arrival directions and compared to the isotropic
expectation.Comment: Accepted for publication in Astroparticle Physics on 31 August 201
Atmospheric effects on extensive air showers observed with the Surface Detector of the Pierre Auger Observatory
Atmospheric parameters, such as pressure (P), temperature (T) and density,
affect the development of extensive air showers initiated by energetic cosmic
rays. We have studied the impact of atmospheric variations on extensive air
showers by means of the surface detector of the Pierre Auger Observatory. The
rate of events shows a ~10% seasonal modulation and ~2% diurnal one. We find
that the observed behaviour is explained by a model including the effects
associated with the variations of pressure and density. The former affects the
longitudinal development of air showers while the latter influences the Moliere
radius and hence the lateral distribution of the shower particles. The model is
validated with full simulations of extensive air showers using atmospheric
profiles measured at the site of the Pierre Auger Observatory.Comment: 24 pages, 9 figures, accepted for publication in Astroparticle
Physic
The exposure of the hybrid detector of the Pierre Auger Observatory
The Pierre Auger Observatory is a detector for ultra-high energy cosmic rays.
It consists of a surface array to measure secondary particles at ground level
and a fluorescence detector to measure the development of air showers in the
atmosphere above the array. The "hybrid" detection mode combines the
information from the two subsystems. We describe the determination of the
hybrid exposure for events observed by the fluorescence telescopes in
coincidence with at least one water-Cherenkov detector of the surface array. A
detailed knowledge of the time dependence of the detection operations is
crucial for an accurate evaluation of the exposure. We discuss the relevance of
monitoring data collected during operations, such as the status of the
fluorescence detector, background light and atmospheric conditions, that are
used in both simulation and reconstruction.Comment: Paper accepted by Astroparticle Physic
The Fluorescence Detector of the Pierre Auger Observatory
The Pierre Auger Observatory is a hybrid detector for ultra-high energy
cosmic rays. It combines a surface array to measure secondary particles at
ground level together with a fluorescence detector to measure the development
of air showers in the atmosphere above the array. The fluorescence detector
comprises 24 large telescopes specialized for measuring the nitrogen
fluorescence caused by charged particles of cosmic ray air showers. In this
paper we describe the components of the fluorescence detector including its
optical system, the design of the camera, the electronics, and the systems for
relative and absolute calibration. We also discuss the operation and the
monitoring of the detector. Finally, we evaluate the detector performance and
precision of shower reconstructions.Comment: 53 pages. Submitted to Nuclear Instruments and Methods in Physics
Research Section
Advanced functionality for radio analysis in the Offline software framework of the Pierre Auger Observatory
The advent of the Auger Engineering Radio Array (AERA) necessitates the
development of a powerful framework for the analysis of radio measurements of
cosmic ray air showers. As AERA performs "radio-hybrid" measurements of air
shower radio emission in coincidence with the surface particle detectors and
fluorescence telescopes of the Pierre Auger Observatory, the radio analysis
functionality had to be incorporated in the existing hybrid analysis solutions
for fluoresence and surface detector data. This goal has been achieved in a
natural way by extending the existing Auger Offline software framework with
radio functionality. In this article, we lay out the design, highlights and
features of the radio extension implemented in the Auger Offline framework. Its
functionality has achieved a high degree of sophistication and offers advanced
features such as vectorial reconstruction of the electric field, advanced
signal processing algorithms, a transparent and efficient handling of FFTs, a
very detailed simulation of detector effects, and the read-in of multiple data
formats including data from various radio simulation codes. The source code of
this radio functionality can be made available to interested parties on
request.Comment: accepted for publication in NIM A, 13 pages, minor corrections to
author list and references in v
Search for First Harmonic Modulation in the Right Ascension Distribution of Cosmic Rays Detected at the Pierre Auger Observatory
We present the results of searches for dipolar-type anisotropies in different
energy ranges above eV with the surface detector array of
the Pierre Auger Observatory, reporting on both the phase and the amplitude
measurements of the first harmonic modulation in the right-ascension
distribution. Upper limits on the amplitudes are obtained, which provide the
most stringent bounds at present, being below 2% at 99% for EeV
energies. We also compare our results to those of previous experiments as well
as with some theoretical expectations.Comment: 28 pages, 11 figure
- …