898 research outputs found
Is Customer Satisfaction Driving Revenue A Longitudinal Analysis With Evidence From The Banking Industry
The connection between customer satisfaction and the financial performance of companies has been under academic scrutiny for quite some time. Evidence regarding the long term impact of customer satisfaction is however relatively scarce. Furthermore, research has so far often neglected potential industry idiosyncrasies in estimating the consequences of changes in customer satisfaction. We provide an insight into the overall long run impact of customer satisfaction on operating revenues based on a longitudinal dataset for the Austrian retail banking industry. Our results corroborate the intuition of a positive long run effect of satisfaction on revenues. We can show, that a time lag of 1,5 years has to elapse for satisfaction to have a positive impact on sales
Nanostructured thermoelectrics: Bi2Te3 / Sb2Te3 based superlattice systems fabricated by MBE and sputtering
Thermoelectric materials yield mutual conversion of thermal to electrical energy by the Seebeck and Peltier effect. Synthesis of thermoelectric materials with high energy conversion efficiencies is a challenge for decades since transport properties are inversely interrelated. For this, semiconducting materials with optimized charge carrier concentration and thus Seebeck coefficients and electrical conductivities, high charge carrier mobilities, and low thermal conductivities are required. It has been proposed to overcome the unfavourable interrelations between the transport properties and increase efficiencies by introducing superlattice (SL) structures in thin films, making use of electron quantum confinement effects and phonon scattering.
The aim of this work was to facilitate the fabrication of high-efficiency Bi2Te3-based thin films and SLs for room temperature applications, using new synthesis routes. Besides Molecular Beam Epitaxy growth on hot substrates, the nanoalloying method was applied, which allows to avoid re-evaporation of the volatile Te and thus control over chemical chemical composition and charge carrier concentration. For this thin element films were deposited by sputtering or evaporation on a cold substrate and annealed ex-situ, yielding the desired Bi2Te3-related compound. In addition, the nanoalloying method allowed to control texture in this highly anisotropic rhombohedral layered material without using substrates with epitaxial relation to the films. Transport properties, chemical composition and texture were measured and correlated for optimizing synthesis parameters. The nanoalloying synthesis method yielded Bi2Te3 - related thin films and SLs with controlled texture and chemical composition and improved efficiencies beyond bulk material’s efficiencies. The films were strongly c-oriented, providing enhanced stability of the SL structures against interdiffusion
Exponentially fast Thinning of Nanoscale Films by Turbulent Mixing
Films are nanoscopic elements of foams, emulsions and suspensions, and form a
paradigm for nanochannel transport that eventually tests the limits of
hydrodynamic descriptions. Here, we study the collapse of a freestanding film
to its equilibrium. The generation of nanoscale films usually is a slow linear
process; using thermal forcing we find unprecedented dynamics with
exponentially fast thinning. The complex interplay of thermal convection,
interface and gravitational forces yields optimal turbulent mixing and
transport. Domains of collapsed film are generated, elongated and convected in
a beautiful display of chaotic mixing. With a timescale analysis we identify
mixing as the dominant dynamical process responsible for exponential thinning.Comment: accepted for publication in Phys. Rev. Let
Macroscopic quantum entanglement between an optomechanical cavity and a continuous field in presence of non-Markovian noise
Probing quantum entanglement with macroscopic objects allows to test quantum
mechanics in new regimes. One way to realize such behavior is to couple a
macroscopic mechanical oscillator to a continuous light field via radiation
pressure. In view of this, the system that is discussed comprises an
optomechanical cavity driven by a coherent optical field in the unresolved
sideband regime where we assume Gaussian states and dynamics. We develop a
framework to quantify the amount of entanglement in the system numerically.
Different from previous work, we treat non-Markovian noise and take into
account both the continuous optical field and the cavity mode. We apply our
framework to the case of the Advanced Laser Interferometer Gravitational-Wave
Observatory (Advanced LIGO) and discuss the parameter regimes where
entanglement exists, even in the presence of quantum and classical noises
Stimulation of autophagy reduces neurodegeneration in a mouse model of human tauopathy
The accumulation of insoluble proteins is a pathological hallmark of several neurodegenerative disorders. Tauopathies are caused by the dysfunction and aggregation of tau protein and an impairment of cellular protein degradation pathways may contribute to their pathogenesis. Thus, a deficiency in autophagy can cause neurodegeneration, while activation of autophagy is protective against some proteinopathies. Little is known about the role of autophagy in animal models of human tauopathy. In the present report, we assessed the effects of autophagy stimulation by trehalose in a transgenic mouse model of tauopathy, the human mutant P301S tau mouse, using biochemical and immunohistochemical analyses. Neuronal survival was evaluated by stereology. Autophagy was activated in the brain, where the number of neurons containing tau inclusions was significantly reduced, as was the amount of insoluble tau protein. This reduction in tau aggregates was associated with improved neuronal survival in the cerebral cortex and the brainstem. We also observed a decrease of p62 protein, suggesting that it may contribute to the removal of tau inclusions. Trehalose failed to activate autophagy in the spinal cord, where it had no impact on the level of sarkosyl-insoluble tau. Accordingly, trehalose had no effect on the motor impairment of human mutant P301S tau transgenic mice. Our findings provide direct evidence in favour of the degradation of tau aggregates by autophagy. Activation of autophagy may be worth investigating in the context of therapies for human tauopathie
- …