1,564 research outputs found
Modification of surface energy in nuclear multifragmentation
Within the statistical multifragmentation model we study modifications of the
surface and symmetry energy of primary fragments in the freeze-out volume. The
ALADIN experimental data on multifragmentation obtained in reactions induced by
high-energy projectiles with different neutron richness are analyzed. We have
extracted the isospin dependence of the surface energy coefficient at different
degrees of fragmentation. We conclude that the surface energy of hot fragments
produced in multifragmentation reactions differs from the values extracted for
isolated nuclei at low excitation. At high fragment multiplicity, it becomes
nearly independent of the neutron content of the fragments.Comment: 11 pages with 13 figure
Control of the woolly apple aphid (Erisoma lanigerum Hausm.) by releasing earwigs (Forficula auricularia L.) and support oil applications - an interim report of first year results
The woolly apple aphid (Erisoma lanigerum Hausm.) has been recognised for some years as
a serious pest in organic fruit growing where they may cause severe economic damage due
to a lack of control strategies. Based on preliminary results a new project has been started in
2007 testing combinations of releasing earwigs and oil applications in order to develop an onfarm
control strategy. In this paper we present preliminary results of the first year of the
project´s field trials. They showed good efficacies for applying oil preparations by brush. The
efficacy of releasing earwigs depended on the infestation intensity
State-Dependent Optical Lattices for the Strontium Optical Qubit
We demonstrate state-dependent optical lattices for the Sr optical qubit at
the tune-out wavelength for its ground state. We tightly trap excited state
atoms while suppressing the effect of the lattice on ground state atoms by more
than four orders of magnitude. This highly independent control over the qubit
states removes inelastic excited state collisions as the main obstacle for
quantum simulation and computation schemes based on the Sr optical qubit. Our
results also reveal large discrepancies in the atomic data used to calibrate
the largest systematic effect of Sr optical lattice clocks.Comment: 6 pages, 4 figures + 6 pages supplemental materia
Interference-contrast optical activity: a new technique for probing the chirality of anisotropic samples and more
We introduce interference-contrast optical activity (ICOA) as a new technique for probing the chirality of anisotropic samples and more. ICOA could underpin a new class of ‘chiral microscopes’, with potential applications spanning the range of chirality and beyond. Two possible versions of ICOA are described explicitly; one designed to probe the optical rotation of a transparent sample regardless of the sample’s linear birefringence (ICOA-OR) and another designed to probe gradients in the optical rotation of a transparent sample (ICOA-GOR). Simulated results for α-quartz lead us to suggest that ICOA-GOR might be applied to help monitor the growth of chiral crystals in the pharmaceutical industry. Possible directions for future research are highlighted
V2:Performance of the solid deuterium ultra-cold neutron source at the pulsed reactor TRIGA Mainz
The performance of the solid deuterium ultra-cold neutron source at the
pulsed reactor TRIGA Mainz with a maximum peak energy of 10 MJ is described.
The solid deuterium converter with a volume of V=160 cm3 (8 mol), which is
exposed to a thermal neutron fluence of 4.5x10^13 n/cm2, delivers up to 550 000
UCN per pulse outside of the biological shield at the experimental area. UCN
densities of ~ 10/cm3 are obtained in stainless steel bottles of V ~ 10 L
resulting in a storage efficiency of ~20%. The measured UCN yields compare well
with the predictions from a Monte Carlo simulation developed to model the
source and to optimize its performance for the upcoming upgrade of the TRIGA
Mainz into a user facility for UCN physics.Comment: 23 pages, 8 figure
The importance of vegetation in understanding terrestrial water storage variations
Funding Information: The article processing charges for this openaccess publication were covered by the Max Planck Society. Publisher Copyright: © 2022 Tina Trautmann et al.So far, various studies have aimed at decomposing the integrated terrestrial water storage variations observed by satellite gravimetry (GRACE, GRACE-FO) with the help of large-scale hydrological models. While the results of the storage decomposition depend on model structure, little attention has been given to the impact of the way that vegetation is represented in these models. Although vegetation structure and activity represent the crucial link between water, carbon, and energy cycles, their representation in large-scale hydrological models remains a major source of uncertainty. At the same time, the increasing availability and quality of Earth-observation-based vegetation data provide valuable information with good prospects for improving model simulations and gaining better insights into the role of vegetation within the global water cycle. In this study, we use observation-based vegetation information such as vegetation indices and rooting depths for spatializing the parameters of a simple global hydrological model to define infiltration, root water uptake, and transpiration processes. The parameters are further constrained by considering observations of terrestrial water storage anomalies (TWS), soil moisture, evapotranspiration (ET) and gridded runoff (Q) estimates in a multi-criteria calibration approach. We assess the implications of including varying vegetation characteristics on the simulation results, with a particular focus on the partitioning between water storage components. To isolate the effect of vegetation, we compare a model experiment in which vegetation parameters vary in space and time to a baseline experiment in which all parameters are calibrated as static, globally uniform values. Both experiments show good overall performance, but explicitly including varying vegetation data leads to even better performance and more physically plausible parameter values. The largest improvements regarding TWS and ET are seen in supply-limited (semi-arid) regions and in the tropics, whereas Q simulations improve mainly in northern latitudes. While the total fluxes and storages are similar, accounting for vegetation substantially changes the contributions of different soil water storage components to the TWS variations. This suggests an important role of the representation of vegetation in hydrological models for interpreting TWS variations. Our simulations further indicate a major effect of deeper moisture storages and groundwater-soil moisture-vegetation interactions as a key to understanding TWS variations. We highlight the need for further observations to identify the adequate model structure rather than only model parameters for a reasonable representation and interpretation of vegetation-water interactions.publishersversionpublishe
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