430 research outputs found
Desarrollo del comportamiento proambiental en los individuos y sus determinantes
Este artículo analiza el comportamiento proambiental en individuos ofreciendo una clasificación del comportamiento según la diversidad/ intensidad de las acciones ambientales emprendidas, y explicando el desarrollo del comportamiento pro-ambiental y algunos de los factores que lo determinan. Mediante análisis cluster y modelos de ecuaciones estructurales, aplicado al Estudio 2837 del CIS, se obtiene una clasificación en cinco grupos de individuos que pone de manifiesto cómo se desarrolla el comportamiento pro-ambiental, desde niveles con poca intensidad en acciones medioambientales muy concretas (como el reciclado) hasta niveles de mayor implicación proambiental en un buen número de acciones proambientales.
The aim of this study is to learn more about pro-environmental conduct in individuals, providing classification in levels of conduct according to diversity/intensity of environmental actions, showing how proenvironmental conduct develops in people and identifying the factors that determine such conduct. The application of cluster analysis and structural equation models to CIS Study 2837 classifies individuals with different degrees of environmental involvement into five groups, showing how pro-environmental conduct develops in people, from specific activities (such as recycling) performed with reduced intensity to greater and more intense pro-environmental involvement
Characterisation and calibration of a scintillating fibre detector with > 4000 multi-anode photomultiplier channels
In the Kaos spectrometer at the Mainz Microtron a high-resolution coordinate
detector for high-energy particles is operated. It consists of scintillating
fibres with diameters of 4000 multi-anode
photomultiplier channels. It is one of the most modern focal-plane detectors
for magnetic spectrometers world-wide. To correct variations in the detection
efficiency, caused by the different gains and the different optical
transmittances, a fully automated off-line calibration procedure has been
developed. The process includes the positioning of a radioisotope source
alongside the detector plane and the automated acquisition and analysis of the
detector signals. It was possible to characterise and calibrate each individual
fibre channel with a low degree of human interaction.Comment: Nucl. Instrum. Meth. A (2012
The association of treatment with hydroxychloroquine and hospital mortality in COVID-19 patients
How is environmental proactivity accomplished? Drivers and barriers in firms' pro-environmental change process
The contaminating effects of economic activity and the scarcity of natural resources has led firms to a situation in which corporate strategy has been compromised by environmental issues. The objective of this paper is to analyse some of the factors determining the pro-environmental change process by considering the drivers encouraging firms to progress in environmental protection and the barriers that curb this progress. Using a structural equation model implemented on a sample of 303 firms, our results confirm a direct and positive effect of stakeholder pressure and of the expectations of obtaining competitive advantages from the pro-environmental change process. The results also confirmed the indirect effect of stakeholder pressure on pro-environmental change through managers'' expectations of obtaining competitive advantages, which play a mediating role in the firm''s response. Although managers interpret the barriers we have studied as obstacles to adopting environmental protection measures, they do not prevent any firm from reaching advanced levels of pro-environmental change
Recoil polarization and beam-recoil double polarization measurement of \eta electroproduction on the proton in the region of the S_{11}(1535) resonance
The beam-recoil double polarization P_{x'}^h and P_{z'}^h and the recoil
polarization P_{y'} were measured for the first time for the
p(\vec{e},e'\vec{p})\eta reaction at a four-momentum transfer of Q^2=0.1
GeV^2/c^2 and a center of mass production angle of \theta = 120^\circ at MAMI
C. With a center of mass energy range of 1500 MeV < W < 1550 MeV the region of
the S_{11}(1535) and D_{13}(1520) resonance was covered. The results are
discussed in the framework of a phenomenological isobar model (Eta-MAID). While
P_{x'}^h and P_{z'}^h are in good agreement with the model, P_{y'} shows a
significant deviation, consistent with existing photoproduction data on the
polarized-target asymmetry.Comment: 4 pages, 1 figur
Search for Light Gauge Bosons of the Dark Sector at the Mainz Microtron
A new exclusion limit for the electromagnetic production of a light U(1)
gauge boson {\gamma}' decaying to e^+e^- was determined by the A1 Collaboration
at the Mainz Microtron. Such light gauge bosons appear in several extensions of
the standard model and are also discussed as candidates for the interaction of
dark matter with standard model matter. In electron scattering from a heavy
nucleus, the existing limits for a narrow state coupling to e^+e^- were reduced
by nearly an order of magnitude in the range of the lepton pair mass of 210
MeV/c^2 < m_e^+e^- < 300 MeV/c^2. This experiment demonstrates the potential of
high current and high resolution fixed target experiments for the search for
physics beyond the standard model.Comment: 4 pages, 7 figure
Measurement of the Target-Normal Single-Spin Asymmetry in Quasielastic Scattering from the Reaction He-3(up arrow) (e,e \u27)
We report the first measurement of the target single-spin asymmetry, A(y), in quasielastic scattering from the inclusive reaction He-3(up arrow)(e,e\u27) on a He-3 gas target polarized normal to the lepton scattering plane. Assuming time-reversal invariance, this asymmetry is strictly zero for one-photon exchange. A nonzero A(y) can arise from the interference between the one-and two-photon exchange processes which is sensitive to the details of the substructure of the nucleon. An experiment recently completed at Jefferson Lab yielded asymmetries with high statistical precision at Q(2) = 0.13, 0.46, and 0.97 GeV2. These measurements demonstrate, for the first time, that the He-3 asymmetry is clearly nonzero and negative at the 4 sigma-9 sigma level. Using measured proton-to-He-3 cross-section ratios and the effective polarization approximation, neutron asymmetries of -(1-3)% were obtained. The neutron asymmetry at high Q(2) is related to moments of the generalized parton distributions (GPDs). Our measured neutron asymmetry at Q(2) = 0.97 GeV2 agrees well with a prediction based on two-photon exchange using a GPD model and thus provides a new, independent constraint on these distributions
Reply to Comment on "High-Precision Determination of the Electric and Magnetic Form Factors of the Proton"
In arXiv:1108.3058v1 [nucl-ex], Arrington criticizes the Coulomb corrections
we applied in the analysis of high precision form factor data (see
Phys.Rev.Lett.105:242001, 2010, arXiv:1007.5076v3 [nucl-ex]). We show, by
comparing different calculations cited in the Comment, that the criticism of
the Comment neglects the large uncertainty of "more modern" TPE corrections.
This uncertainty has also been seen in recent polarized measurements. We rerun
our analysis using one of these calculations. The results show that the Comment
exaggerates the quantitative effect at small Q^2.Comment: 1 page, 2 figure, To appear as a Reply Comment in Physical Review
Letter
The electric and magnetic form factors of the proton
The paper describes a precise measurement of electron scattering off the
proton at momentum transfers of \ GeV. The
average point-to-point error of the cross sections in this experiment is
0.37%. These data are used for a coherent new analysis together with all world
data of unpolarized and polarized electron scattering from the very smallest to
the highest momentum transfers so far measured. The extracted electric and
magnetic form factors provide new insight into their exact shape, deviating
from the classical dipole form, and of structure on top of this gross shape.
The data reaching very low values are used for a new determination of the
electric and magnetic radii. An empirical determination of the
Two-Photon-Exchange (TPE) correction is presented. The implications of this
correction on the radii and the question of a directly visible signal of the
pion cloud are addressed.Comment: 38 pages, 20 figures. Updated data files. PRC versio
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