7,974 research outputs found
A COMPARISON OF HYPOTHETICAL PHONE AND MAIL CONTINGENT VALUATION RESPONSES FOR GREEN PRICING ELECTRICITY PROGRAMS
To date, much of the policy and research debate on contingent valuation mode effects has relied on experiences drawn from other research disciplines. This study provides the first contingent valuation phone-mail comparison that meets current standards for response rates, draws from a general population, is relevant to the valuation of general environmental goods, and allows comparisons with actual sign-ups. Consistent with previous research in other disciplines, social desirability bias is found in responses to subjective questions --thus leading to more environmentally favorable responses on the phone. However, this effect does not carry over to hypothetical participation decisions. Hypothetical bias is found in both modes. Yet, application of calibration methods using debriefing questions provided nearly identical values across modes. As such, neither mode appears to dominate from the perspective of providing more valid estimates of actual participation decisions. The selection of survey mode must be based on other criteria.Environmental Economics and Policy,
ZUR BEURTEILUNG DER REIBSENKENDEN UND VERSCHLEISSMINDERNDEN EIGENSCHAFTEN VON SCHMIERĂ–LEN UNTER LABORBEDINGUNGEN
Ionization by bulk heating of electrons in capacitive radio frequency atmospheric pressure microplasmas
Electron heating and ionization dynamics in capacitively coupled radio
frequency (RF) atmospheric pressure microplasmas operated in helium are
investigated by Particle in Cell simulations and semi-analytical modeling. A
strong heating of electrons and ionization in the plasma bulk due to high bulk
electric fields are observed at distinct times within the RF period. Based on
the model the electric field is identified to be a drift field caused by a low
electrical conductivity due to the high electron-neutral collision frequency at
atmospheric pressure. Thus, the ionization is mainly caused by ohmic heating in
this "Omega-mode". The phase of strongest bulk electric field and ionization is
affected by the driving voltage amplitude. At high amplitudes, the plasma
density is high, so that the sheath impedance is comparable to the bulk
resistance. Thus, voltage and current are about 45{\deg} out of phase and
maximum ionization is observed during sheath expansion with local maxima at the
sheath edges. At low driving voltages, the plasma density is low and the
discharge becomes more resistive resulting in a smaller phase shift of about
4{\deg}. Thus, maximum ionization occurs later within the RF period with a
maximum in the discharge center. Significant analogies to electronegative low
pressure macroscopic discharges operated in the Drift-Ambipolar mode are found,
where similar mechanisms induced by a high electronegativity instead of a high
collision frequency have been identified
Remarks on the self-shrinking Clifford torus
On the one hand, we prove that the Clifford torus in is
unstable for Lagrangian mean curvature flow under arbitrarily small Hamiltonian
perturbations, even though it is Hamiltonian -stable and locally area
minimising under Hamiltonian variations. On the other hand, we show that the
Clifford torus is rigid: it is locally unique as a self-shrinker for mean
curvature flow, despite having infinitesimal deformations which do not arise
from rigid motions. The proofs rely on analysing higher order phenomena:
specifically, showing that the Clifford torus is not a local entropy minimiser
even under Hamiltonian variations, and demonstrating that infinitesimal
deformations which do not generate rigid motions are genuinely obstructed.Comment: 31 pages, v3: additional details for proof of local uniqueness of the
Clifford torus as a self-shrinker provide
Scalar correlations in a quark plasma and low mass dilepton production
We investigate possible consequences of resonant scalar interactions for
dilepton production from a quark plasma at the chiral phase transition. It is
found that this production mechanism is strongly suppressed compared to the
Born process and has no significance for present experiments.Comment: 7 pages revtex, 2 ps figure
Mineralogy of soils with unusually high exchangeable Al from the western Amazon region.
Some soils from the western Amazon region contain KCl-extractable Al contents 5 to 10 times greater than is typical for highly weathered soils containing predominantly kaolinite and gibbsite. We studied a soil sequence from the Brazilian western Amazon consisting of two Typic Udifluvents on the levee of the Javari River, onde Aeric Endoaquent in the backswamp, and two Typic Hapludults on an adjacent terrace
Enhanced Detection of Emotional Facial Expressions in Borderline Personality Disorder
Background: Borderline personality disorder (BPD) is commonly proposed to be
characterized by an enhanced sensitivity for emotional stimuli. In the present
study, we investigated whether BPD patients show a superior detection of
emotional facial expressions relative to healthy controls. The detection of
emotional information in the environment represents an important facet of
emotional sensitivity. Sampling and Methods: Twenty patients with BPD were
compared with 25 healthy controls. The participants were presented a rapid,
continuous stream of neutral and randomly inserted emotional facial
expressions and were asked to report the presentation of an emotional facial
stimulus after each trial. Availability of cognitive resources was manipulated
via two different task demands. Results: The participants with BPD performed
significantly better in the detection of positive and negative facial
expressions compared to the healthy controls. False alarm rates did not differ
significantly between the two groups. Conclusions: The BPD participants showed
an enhanced detection of emotional expressions that might be related to the
emotional disturbances they experience. In particular, we will discuss the
role of this superior emotion detection (in combination with previously
reported deficits in the labeling of emotional states) for the understanding
of emotional instability in BPD
Tunable sub-luminal propagation of narrowband x-ray pulses
Group velocity control is demonstrated for x-ray photons of 14.4 keV energy
via a direct measurement of the temporal delay imposed on spectrally narrow
x-ray pulses. Sub-luminal light propagation is achieved by inducing a steep
positive linear dispersion in the optical response of Fe M\"ossbauer
nuclei embedded in a thin film planar x-ray cavity. The direct detection of the
temporal pulse delay is enabled by generating frequency-tunable spectrally
narrow x-ray pulses from broadband pulsed synchrotron radiation. Our
theoretical model is in good agreement with the experimental data.Comment: 8 pages, 4 figure
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