11,651 research outputs found
Determination of the sticking probability of hydrocarbons on an amorphous hydrocarbons surface
Solitonic spin-liquid state due to the violation of the Lifshitz condition in FeTe
A combination of phenomenological analysis and M\"ossbauer spectroscopy
experiments on the tetragonal FeTe system indicates that the magnetic
ordering transition in compounds with higher Fe-excess, 0.11, is
unconventional. Experimentally, a liquid-like magnetic precursor with
quasi-static spin-order is found from significantly broadened M\"ossbauer
spectra at temperatures above the antiferromagnetic transition. The
incommensurate spin-density wave (SDW) order in FeTe is described by a
magnetic free energy that violates the weak Lifshitz condition in the Landau
theory of second-order transitions. The presence of multiple Lifshitz
invariants provides the mechanism to create multidimensional, twisted, and
modulated solitonic phases.Comment: 5 pages, 2 figure
Pressure-induced ferromagnetism due to an anisotropic electronic topological transition in Fe1.08Te
A rapid and anisotropic modification of the Fermi-surface shape can be
associated with abrupt changes in crystalline lattice geometry or in the
magnetic state of a material. In this study we show that such an electronic
topological transition is at the basis of the formation of an unusual
pressure-induced tetragonal ferromagnetic phase in FeTe. Around 2 GPa,
the orthorhombic and incommensurate antiferromagnetic ground-state of
FeTe is transformed upon increasing pressure into a tetragonal
ferromagnetic state via a conventional first-order transition. On the other
hand, an isostructural transition takes place from the paramagnetic
high-temperature state into the ferromagnetic phase as a rare case of a `type
0' transformation with anisotropic properties. Electronic-structure
calculations in combination with electrical resistivity, magnetization, and
x-ray diffraction experiments show that the electronic system of FeTe
is instable with respect to profound topological transitions that can drive
fundamental changes of the lattice anisotropy and the associated magnetic
order.Comment: 7 pages, 4 figur
Are We All in the Same Boat? The Role of Perceptual Distance in Organizational Health Interventions
The study investigates how agreement between leaders' and their team's perceptions influence intervention outcomes in a leadership-training intervention aimed at improving organizational learning. Agreement, i.e. perceptual distance was calculated for the organizational learning dimensions at baseline. Changes in the dimensions from pre-intervention to post-intervention were evaluated using polynomial regression analysis with response surface analysis. The general pattern of the results indicated that the organizational learning improved when leaders and their teams agreed on the level of organizational learning prior to the intervention. The improvement was greatest when the leader's and the team's perceptions at baseline were aligned and high rather than aligned and low. The least beneficial scenario was when the leader's perceptions were higher than the team's perceptions. These results give insights into the importance of comparing leaders' and their team's perceptions in intervention research. Polynomial regression analyses with response surface methodology allow three-dimensional examination of relationship between two predictor variables and an outcome. This contributes with knowledge on how combination of predictor variables may affect outcome and allows studies of potential non-linearity relating to the outcome. Future studies could use these methods in process evaluation of interventions
Leading well is a matter of resources : leader vigour and peer support augments the relationship between transformational leadership and burnout
Although studies suggest that transformational leaders play an important role in employee health and well-being, the relationship between transformational leadership and employee burnout remains unclear. One reason may be that moderators may play an important role. Building on conservation of resources theory, we examined if leaders’ perceptions of internal and external resources in terms of vigour and peer support augmented the relationship between transformational leadership and employee burnout in a sample of municipality workers and their leaders in Sweden (N = 217). Multilevel analyses over two time points revealed that both vigour and peer support enhance this relationship, such that when leaders experience high levels of vigour or peer support, the negative relationship between transformational leadership behaviours and employee burnout was strengthened. Our findings suggest that both personal and contextual resources may help leaders to better engage in transformational leadership, which is important in order to protect employees from burning out
Coherent laminar and turbulent motion of toroidal vortex bundles
Motivated by experiments performed in superfluid helium, we study numerically
the motion of toroidal bundles of vortex filaments in an inviscid fluid. We
find that the evolution of these large-scale vortex structures involves the
generalised leapfrogging of the constituent vortex rings. Despite three
dimensional perturbations in the form of Kelvin waves and vortex reconnections,
toroidal vortex bundles retain their coherence over a relatively large distance
(compared to their size), in agreement with experimental observations.Comment: 22 pages, 12 figure
No leader is an island : contextual antecedents to line managers’ constructive and destructive leadership during an organizational intervention
Purpose: Line managers can make or break organizational interventions, yet little is known about what makes them turn in either direction. As leadership does not occur in a vacuum it has been suggested that the organizational context plays an important role. Building on the intervention and leadership literature, we examine if span of control and employee readiness for change are related to line managers’ leadership during an organizational intervention.
Design: Leadership is studied in terms of intervention-specific constructive, as well as passive and active forms of destructive, leadership behaviors. As a sample, we use employees (N = 172) from 37 groups working at a process industry plant. Multilevel analyses over two time points, with both survey and organizational register data were used to analyze the data.
Findings: The results revealed that span of control was negatively related to constructive leadership and positively related to passive destructive leadership during the intervention. Employee readiness for change was positively related to constructive leadership, and negatively related to both passive and active destructive leadership.
Practical implications: Our findings suggest that contextual factors need to be assessed and considered if we want line managers to engage in constructive rather than destructive leadership during interventions.
Originality/value: The present study is the first to address line managers’ making or breaking of organizational interventions by examining the influence of context on both their destructive and constructive leadership
First-order structural transition in the magnetically ordered phase of Fe1.13Te
Specific heat, resistivity, magnetic susceptibility, linear thermal expansion
(LTE), and high-resolution synchrotron X-ray powder diffraction investigations
of single crystals Fe1+yTe (0.06 < y < 0.15) reveal a splitting of a single,
first-order transition for y 0.12. Most
strikingly, all measurements on identical samples Fe1.13Te consistently
indicate that, upon cooling, the magnetic transition at T_N precedes the
first-order structural transition at a lower temperature T_s. The structural
transition in turn coincides with a change in the character of the magnetic
structure. The LTE measurements along the crystallographic c-axis displays a
small distortion close to T_N due to a lattice striction as a consequence of
magnetic ordering, and a much larger change at T_s. The lattice symmetry
changes, however, only below T_s as indicated by powder X-ray diffraction. This
behavior is in stark contrast to the sequence in which the phase transitions
occur in Fe pnictides.Comment: 6 page
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