Pottery in the computer age

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Dispersive diffusion controlled distance dependent recombination in amorphous semiconductors

The photoluminescence in amorphous semiconductors decays according to power law $t^{-delta}$ at long times. The photoluminescence is controlled by dispersive transport of electrons. The latter is usually characterized by the power $alpha$ of the transient current observed in the time-of-flight experiments. Geminate recombination occurs by radiative tunneling which has a distance dependence. In this paper, we formulate ways to calculate reaction rates and survival probabilities in the case carriers execute dispersive diffusion with long-range reactivity. The method is applied to obtain tunneling recombination rates under dispersive diffusion. The theoretical condition of observing the relation $delta = alpha/2 + 1$ is obtained and theoretical recombination rates are compared to the kinetics of observed photoluminescence decay in the whole time range measured.Comment: To appear in Journal of Chemical Physic

Structural Properties of the Disordered Spherical and other Mean Field Spin Models

We extend the approach of Aizenman, Sims and Starr for the SK-type models to their spherical versions. Such an extension has already been performed for diluted spin glasses. The factorization property of the optimal structures found by Guerra for the SK model, which holds for diluted models as well, is verified also in the case of spherical systems, with the due modifications. Hence we show that there are some common structural features in various mean field spin models. These similarities seem to be quite paradigmatic, and we summarize the various techniques typically used to prove the structural analogies and to tackle the computation of the free energy per spin in the thermodynamic limit.Comment: 24 page

Barriers and Facilitators of Suicide Risk Assessment in Emergency Departments: A Qualitative Study of Provider Perspectives

Objective To understand emergency department (ED) providers’ perspectives regarding the barriers and facilitators of suicide risk assessment and to use these perspectives to inform recommendations for best practices in ED suicide risk assessment. Methods Ninety-two ED providers from two hospital systems in a Midwestern state responded to open-ended questions via an online survey that assessed their perspectives on the barriers and facilitators to assess suicide risk as well as their preferred assessment methods. Responses were analyzed using an inductive thematic analysis approach. Results Qualitative analysis yielded six themes that impact suicide risk assessment. Time, privacy, collaboration and consultation with other professionals and integration of a standard screening protocol in routine care exemplified environmental and systemic themes. Patient engagement/participation in assessment and providers’ approach to communicating with patients and other providers also impacted the effectiveness of suicide risk assessment efforts. Conclusions The findings inform feasible suicide risk assessment practices in EDs. Appropriately utilizing a collaborative, multidisciplinary approach to assess suicide-related concerns appears to be a promising approach to ameliorate the burden placed on ED providers and facilitate optimal patient care. Recommendations for clinical care, education, quality improvement and research are offered