144 research outputs found
Selbst gemacht ist gut gemacht? Der Einfluss von Self-Service Reporting auf die QualitÀt von Managemententscheidungen
Instrumente des Self-Service Reportings haben das Potenzial, datengetriebene Entscheidungsfindung auf allen Ebenen zu ermöglichen oder zu erleichtern. Der Einsatz dieser Technologie wird maĂgebliche VerĂ€nderungen des Entscheidungsverhaltens mit sich bringen. Bisher existieren wenige wissenschaftliche Erkenntnisse darĂŒber, wie der Einsatz von Self-Service Reporting die QualitĂ€t der getroffenen Entscheidungen beeinflusst. Diese Arbeit geht eben jener Frage nach und untersucht die Auswirkungen auf die QualitĂ€t sowie die Bereitschaft zum Treffen der Entscheidung in einem Investitionskontext. Es wird ein Experiment mit zwei Gruppen durchgefĂŒhrt, bei dem die Probanden auf der Basis unterschiedlich prĂ€sentierter Informationen eine Auswahl vornehmen mĂŒssen. Die Ergebnisse des Experiments zeigen, dass der Einsatz von Self-Service Reporting einen negativen Einfluss auf die QualitĂ€t von Entscheidungen hat und zu einer geminderten Entscheidungsbereitschaft fĂŒhrt.
Keywords: Self-Service; Entscheidungsverhalten; Investition; Bias
Perpendicularly magnetized Mn-Co-Ga-based thin films with high coercive field
MnCoGa epitaxial thin films were grown on MgO substrates by
magnetron co-sputtering. Structures were tetragonal or cubic depending on Co
content. Composition dependence of saturation magnetization and uniaxial
magnetic anisotropy of the films were investigated. A high (1.2 MJ
m) was achieved for the MnCoGa film with the
magnetic moment 0.84. Valence band spectra were obtained by hard X-ray
photoelectron spectroscopy. Sharp peaks in the cubic case, which were absent in
the tetragonal case, prove that a van Hove singularity causes a band
Jahn-Teller effect with tetragonal distortion. Observations agree well with the
first-principles calculations
Completely compensated ferrimagnetism and sublattice spin crossing in the half-metallic Heusler compound Mn1.5FeV0.5Al
The Slater-Pauling rule states that L21 Heusler compounds with 24 valence
electrons do never exhibit a total spin magnetic moment. In case of strongly
localized magnetic moments at one of the atoms (here Mn) they will exhibit a
fully compensated half-metallic ferrimagnetic state instead, in particular,
when symmetry does not allow for antiferromagnetic order. With aid of magnetic
and anomalous Hall effect measurements it is experimentally demonstrated that
Mn1.5V0.5FeAl follows such a scenario. The ferrimagnetic state is tuned by the
composition. A small residual magnetization, that arises due to a slight
mismatch of the magnetic moments in the different sublattices results in a
pronounced change of the temperature dependence of the ferrimagnet. A
compensation point is confirmed by observation of magnetic reversal and sign
change of the anomalous Hall effect. Theoretical models are presented that
correlate the electronic structure and the compensation mechanisms of the
different half-metallic ferrimagnetic states in the Mn-V-Fe-Al Heusler system.Comment: Under revie
Evidence for Localized Moment Picture in Mn-based Heusler Compounds
X-ray absorption spectroscopy (XAS) and X-ray magnetic circular dichroism
(XMCD) were used to probe the oxidation state and element specific magnetic
moments of Mn in Heusler compounds with different crystallographic structure.
The results were compared with theoretical calculations, and it was found that
in full Heusler alloys, Mn is metallic (oxidation state near 0) on both
sublattices. The magnetic moment is large and localized when octahedrally
coordinated by the main group element, consistent with previous theoretical
work, and reduced when the main group coordination is tetrahedral. By contrast,
in the half Heusler compounds the magnetic moment of the Mn atoms is large and
the oxidation state is +1 or +2. The magnetic and electronic properties of Mn
in full and half Heusler compounds are strongly dependent on the structure and
sublattice, a fact that can be exploited to design new materials.Comment: 15 pages, 4 figure
From colossal to zero: Controlling the Anomalous Hall Effect in Magnetic Heusler Compounds via Berry Curvature Design
Since the discovery of the anomalous Hall effect (AHE), the anomalous Hall
conductivity (AHC) has been thought to be zero when there is no net
magnetization. However, the recently found relation between the intrinsic AHE
and the Berry curvature predicts other possibilities, such as a large AHC in
non-colinear antiferromagnets with no net magnetization but net Berry
curvature. Vice versa, the AHE in principle could be tuned to zero,
irrespective of a finite magnetization. Here, we experimentally investigate
this possibility and demonstrate that, the symmetry elements of Heusler magnets
can be changed such that the Berry curvature and all the associated properties
are switched while leaving the magnetization unaffected. This enables us to
tune the AHC from 0 {\Omega}-1cm-1 up to 1600 {\Omega}-1cm-1 with an
exceptionally high anomalous Hall angle up to 12 %, while keeping the
magnetization same. Our study shows that the AHC can be controlled by
selectively changing the Berry curvature distribution, independent of the
magnetization.Comment: Published in Physical Review X. 16 pages, 5 figure
Recommended from our members
From Colossal to Zero: Controlling the Anomalous Hall Effect in Magnetic Heusler Compounds via Berry Curvature Design
Since the discovery of the anomalous Hall effect (AHE), the anomalous Hall conductivity (AHC) has been thought to be zero when there is no net magnetization. However, the recently found relation between the intrinsic AHE and the Berry curvature predicts other possibilities, such as a large AHC in noncolinear antiferromagnets with no net magnetization but net Berry curvature. Vice versa, the AHE in principle could be tuned to zero, irrespective of a finite magnetization. Here, we experimentally investigate this possibility and demonstrate that the symmetry elements of Heusler magnets can be changed such that the Berry curvature and all the associated properties are switched while leaving the magnetization unaffected. This enables us to tune the AHC from 0 Ω-1 cm-1 up to 1600 Ω-1 cm-1 with an exceptionally high anomalous Hall angle up to 12%, while keeping the magnetization the same. Our study shows that the AHC can be controlled by selectively changing the Berry curvature distribution, independent of the magnetization
a review
It is well documented that global warming is unequivocal. Dairy production
systems are considered as important sources of greenhouse gas emissions;
however, little is known about the sensitivity and vulnerability of these
production systems themselves to climate warming. This review brings different
aspects of dairy cow production in Central Europe into focus, with a holistic
approach to emphasize potential future consequences and challenges arising
from climate change. With the current understanding of the effects of climate
change, it is expected that yield of forage per hectare will be influenced
positively, whereas quality will mainly depend on water availability and soil
characteristics. Thus, the botanical composition of future grassland should
include species that are able to withstand the changing conditions (e.g.
lucerne and bird's foot trefoil). Changes in nutrient concentration of forage
plants, elevated heat loads and altered feeding patterns of animals may
influence rumen physiology. Several promising nutritional strategies are
available to lower potential negative impacts of climate change on dairy cow
nutrition and performance. Adjustment of feeding and drinking regimes, diet
composition and additive supplementation can contribute to the maintenance of
adequate dairy cow nutrition and performance. Provision of adequate shade and
cooling will reduce the direct effects of heat stress. As estimated genetic
parameters are promising, heat stress tolerance as a functional trait may be
included into breeding programmes. Indirect effects of global warming on the
health and welfare of animals seem to be more complicated and thus are less
predictable. As the epidemiology of certain gastrointestinal nematodes and
liver fluke is favourably influenced by increased temperature and humidity,
relations between climate change and disease dynamics should be followed
closely. Under current conditions, climate change associated economic impacts
are estimated to be neutral if some form of adaptation is integrated.
Therefore, it is essential to establish and adopt mitigation strategies
covering available tools from management, nutrition, health and plant and
animal breeding to cope with the future consequences of climate change on
dairy farming
Bringing Stellar Evolution & Feedback Together: Summary of proposals from the Lorentz Center Workshop, 2022
Stars strongly impact their environment, and shape structures on all scales
throughout the universe, in a process known as ``feedback''. Due to the
complexity of both stellar evolution and the physics of larger astrophysical
structures, there remain many unanswered questions about how feedback operates,
and what we can learn about stars by studying their imprint on the wider
universe. In this white paper, we summarize discussions from the Lorentz Center
meeting `Bringing Stellar Evolution and Feedback Together' in April 2022, and
identify key areas where further dialogue can bring about radical changes in
how we view the relationship between stars and the universe they live in.Comment: Accepted to the Publications of the Astronomical Society of the
Pacifi
- âŠ