Classical and all-floating FETI methods for the simulation of arterial tissues

High-resolution and anatomically realistic computer models of biological soft tissues play a significant role in the understanding of the function of cardiovascular components in health and disease. However, the computational effort to handle fine grids to resolve the geometries as well as sophisticated tissue models is very challenging. One possibility to derive a strongly scalable parallel solution algorithm is to consider finite element tearing and interconnecting (FETI) methods. In this study we propose and investigate the application of FETI methods to simulate the elastic behavior of biological soft tissues. As one particular example we choose the artery which is - as most other biological tissues - characterized by anisotropic and nonlinear material properties. We compare two specific approaches of FETI methods, classical and all-floating, and investigate the numerical behavior of different preconditioning techniques. In comparison to classical FETI, the all-floating approach has not only advantages concerning the implementation but in many cases also concerning the convergence of the global iterative solution method. This behavior is illustrated with numerical examples. We present results of linear elastic simulations to show convergence rates, as expected from the theory, and results from the more sophisticated nonlinear case where we apply a well-known anisotropic model to the realistic geometry of an artery. Although the FETI methods have a great applicability on artery simulations we will also discuss some limitations concerning the dependence on material parameters.Comment: 29 page

Thermal kinetic inductance detectors for ground-based millimeter-wave cosmology

We show measurements of thermal kinetic inductance detectors (TKID) intended for millimeter wave cosmology in the 200-300 GHz atmospheric window. The TKID is a type of bolometer which uses the kinetic inductance of a superconducting resonator to measure the temperature of the thermally isolated bolometer island. We measure bolometer thermal conductance, time constant and noise equivalent power. We also measure the quality factor of our resonators as the bath temperature varies to show they are limited by effects consistent with coupling to two level systems.Comment: 8 pages, 4 figures. Submitted to Journal of Low Temperature Physic

Phase field modelling of grain boundary premelting using obstacle potentials

We investigate the multi-order parameter phase field model of Steinbach and Pezzolla [I. Steinbach, F. Pezzolla, A generalized field method for multiphase transformations using interface fields, Physica D 134 (1999) 385-393] concerning its ability to describe grain boundary premelting. For a single order parameter situation solid-melt interfaces are always attractive, which allows to have (unstable) equilibrium solid-melt-solid coexistence above the bulk melting point. The temperature dependent melt layer thickness and the disjoining potential, which describe the interface interaction, are affected by the choice of the thermal coupling function and the measure to define the amount of the liquid phase. Due to the strictly finite interface thickness also the interaction range is finite. For a multi-order parameter model we find either purely attractive or purely repulsive finite-ranged interactions. The premelting transition is then directly linked to the ratio of the grain boundary and solid-melt interfacial energy.Comment: 12 page

Realization of a space reversal operator

In this paper we propose the realization of a bosonic-fermionic interaction in the context of trapped ions whose effect upon the ion center of mass degrees of freedom is properly speaking a spatial inversion. The physical system and its features are accurately described and some applications are briefly discussed.Comment: 9 pages; to appear in Rep. Math. Phys., in summer 200

In Search of the Optimal CRM Curriculum: A Skills Framework for the Salesforce Administrator Role

Customer relationship management (CRM) systems, the enterprise systems used to digitize aspects of the sales, support, & marketing functions, are heavily adopted throughout industry, resulting in demand for skilled employees. Higher education is generally expected to respond to industry needs, and assessing these needs is a long-standing task in Information Systems (IS) pedagogy. A recent paper suggests that CRM curricula in higher education is often inadequate and proposes a skills framework for a CRM Analyst. We leverage this skills framework to perform a content analysis of 61 job listings for Salesforce Administrator roles. Our framework indicates that a CRM curriculum should generate student competence in the categories of data & middleware, soft skills, project management & business analysis skills, and to obtain a baseline Salesforce Administrator certification. These findings can assist instructors in developing CRM courses and programs and expand our existing understanding of CRM pedagogy

Thermal Kinetic Inductance Detectors for Millimeter-Wave Astrophysics

Thermal Kinetic Inductance Detectors (TKIDs) combine the excellent noise performance of traditional bolometers with a radio frequency (RF) multiplexing architecture that enables the large detector counts needed for the next generation of millimeter-wave instruments. Here we present dark prototype TKID pixels that demonstrate a noise equivalent power NEP = 2×10⁻¹⁷√W/Hz with a 1/f knee at 0.1 Hz, suitable for background-limited noise performance at 150 GHz from a ground-based site. We discuss the optimizations in the device design and fabrication techniques to realize optimal electrical performance and high quality factors at a bath temperature of 250 mK

The Survey on "Family Models in Germany" (FAMOD): a Description of the Data

The FAMOD project, which is funded by the German Research Foundation (DFG), investigates the diversity of existing family Models after separation or divorce in Germany. The project’s aim is to provide detailed information about the living conditions of mothers, fathers, and children in different post-separation family configurations, namely in sole physical custody (SPC) and in joint physical custody (JPC) arrangements. Employing a multi-actor design, the survey closely examines the well-being of the Individual family members in order to identify the potentials and challenges within a specific physical custody care arrangement. Because JPC families are still extremely rare in Germany (less than 1% of all families with minor children), this project is the first to collect data from a sufficient number of JPC families for detailed statistical analyses. Based on a quota sample, FAMOD provides data of 1,554 families in Germany (nuclear, SPC, and JPC families). This working paper contains a description of the sampling procedure, details about the process of data collection, and a benchmarking of selected core sociodemographic variables against the results from other German surveys