Polaronic signature in the metallic phase of La0.7Ca0.3MnO3 films detected by scanning tunneling spectroscopy

In this work we map tunnel conductance curves with nanometric spatial resolution, tracking polaronic quasiparticle excitations when cooling across the insulator-to-metal transition in La0.7Ca0.3MnO3 films. In the insulating phase the spectral signature of polarons, a depletion of conductance at low bias flanked by peaks, is detected all over the scanned surface. These features are still observed at the transition and persist on cooling into the metallic phase. Polaron-binding energy maps reveal that polarons are not confined to regions embedded in a highly-conducting matrix but are present over the whole field of view both above and below the transition temperature.Comment: 10 pages, 4 figure

Two-point density correlations of quasicondensates in free expansion

We measure the two-point density correlation function of freely expanding quasicondensates in the weakly interacting quasi-one-dimensional (1D) regime. While initially suppressed in the trap, density fluctuations emerge gradually during expansion as a result of initial phase fluctuations present in the trapped quasicondensate. Asymptotically, they are governed by the thermal coherence length of the system. Our measurements take place in an intermediate regime where density correlations are related to near-field diffraction effects and anomalous correlations play an important role. Comparison with a recent theoretical approach described by Imambekov et al. yields good agreement with our experimental results and shows that density correlations can be used for thermometry of quasicondensates.Comment: 4 pages, 4 figures, minor change

Aspects of the FM Kondo Model: From Unbiased MC Simulations to Back-of-an-Envelope Explanations

Effective models are derived from the ferromagnetic Kondo lattice model with classical corespins, which greatly reduce the numerical effort. Results for these models are presented. They indicate that double exchange gives the correct order of magnitude and the correct doping dependence of the Curie temperature. Furthermore, we find that the jump in the particle density previously interpreted as phase separation is rather explained by ferromagnetic polarons.Comment: Proceedings of Wandlitz Days of Magnetism 200

A Calculation of the ESR Parameters of the Hydrogen Bonded Complex Radical (H2NO ... HF)

The isotropic constant (a) and the dipolar tensor (B) have been calculated for the radical H2NO bonded to HF. The semiempirical SCF (INDO) method has been used to describe the electronic configuration of the complex radical H2NO ... HF. It is suggested that a and B of the proton from HF are amenable to experimental verification

A Calculation of the ESR Parameters of the Hydrogen Bonded Complex Radical (H2NO ... HF)

The isotropic constant (a) and the dipolar tensor (B) have been calculated for the radical H2NO bonded to HF. The semiempirical SCF (INDO) method has been used to describe the electronic configuration of the complex radical H2NO ... HF. It is suggested that a and B of the proton from HF are amenable to experimental verification

Caring for the Caregiver: A Feasibility Study of an Online Program that Addresses Compassion Fatigue, Burnout, and Secondary Trauma

Background: Informal caregivers are susceptible to compassion fatigue in vicarious response to another’s suffering. The purpose of the study was to determine the feasibility of an online program that addresses compassion fatigue, burnout, and secondary traumatic stress in informal caregivers. Method: The study used a pre-post repeated measures feasibility design. Eighty-six participants were initially recruited. The intervention consisted of a 70-min online program. The participants completed surveys before and after program completion. The number of participants that completed each study phase was recorded to determine feasibility outcomes of acceptability, implementation, and demand. A Wilcoxon signed-rank test was employed to analyze survey results. Results: Ten participants completed all study phases. Of the participants recruited and consented to participate, 29% completed part of the program, 12% completed all phases, and 70% reported they would recommend the online program. The results of the Wilcoxon signed-rank test revealed that completion of the online program elicited a significant change in secondary traumatic stress-related outcomes. Conclusion: Findings provided preliminary evidence suggesting that the online program may be a feasible intervention to support informal caregiver mental health. Future efficacy testing of the online program is needed with specific consideration of the COVID-19 pandemic and resulting social isolation impacting mental health

A comparison of charcoal- and slag-based constructed wetlands for acid mine drainage remediation

Subsurface-flow constructed wetlands (CW) with charcoal- or slag-based bed matrices were investigated for their potential use in remediating acid mine drainage (AMD). A CW is effectively a reactor in which some components of the wastewater are broken down by the organisms occurring within the CW, whilst others may be degraded by physico-chemical processes or a combination thereof. Two 200 ℓ small-scale CWs were built at the University. Commercially available charcoal and <19 mm basic oxygen furnace (BOF) slag were used as the bed matrices and the units were planted with a variety of plants. The units were exposed to an artificial AMD. The results showed that the systems removed almost all soluble iron and more than 75% of the sulphate. Both CWs were able to increase the pH of the AMD.Keywords: AMD, charcoal, slag, constructed wetlands, remediatio