The power of adaptiveness and additional queries in random-self-reductions

We study random-self-reductions from a structural complexity-theoretic point of view. Specifically, we look at relationships between adaptive and nonadaptive random-self-reductions. We also look at what happens to random-self-reductions if we restrict the number of queries they are allowed to make. We show the following results:

Correction to: When terminology hinders research: the colloquialisms of transitions of control in automated driving

Cognition, Technology & Work -     

Experimental investigation and simulation of machining thin-walled workpieces

An enhanced simulation model is presented in this paper to predict form deviations in end milling processes of thin-walled structures. The calculation of tool engagement is based on level curves representing surface geometry of the workpiece and the NC code driven sweep volume. To consider influences of force-induced deflections resulting in static form errors on machined surface of the workpiece, a model for superposed stresses is enclosed. Derived from the tool engagement, the cutting force is predicted using a parametric force model. The experimental investigations within the measuring of static and dynamic form errors during processing and afterwards are shown and measurement results are compared with results of the cutting simulation to verify the proposed method. The presented achievements are deduced from research activities aiming at an increased understanding of shape deviation induced by interactions between tool, workpiece and clamping device during machining.     

Silicon Availability Affects the Stoichiometry and Content of Calcium and Micro Nutrients in the Leaves of Common Reed

Purpose

Although silicon is not an essential element in sensu stricto for plant growth, it affects plant stress resistance and may affect the composition of cell wall compounds, especially of grasses. Where silicon availability alters the stoichiometry of macro nutrients in grasses, data on the interaction with calcium and micro nutrients are rare and hence are focussed on in this study.

Methods

The effect of silicon availability on calcium and micro nutrient content of the leaf blades of common reed, Phragmites australis, were assessed in a pot experiment with three levels of silicon supply.

Results

Calcium and micro nutrient concentrations and stoichiometry in leaf blades is altered by changing silicon availability during plant growth. In addition, Scanning Electron Microscopy (SEM) reveals that elevated silicon supply promotes silica deposition and changes the element content of micro and macro nutrients in the near epidermis tissue of P. australis leaves.

Conclusion

Silicon availability has a major impact on calcium and micro nutrient content and stoichiometry in grasses. This in turn may considerably affect the nutrient cycling in grass dominated ecosystems.     

Analysis of Annular Thermoelectric Couples with Nonuniform Temperature Distribution by Means of 3-D Multiphysics Simulation

Thermoelectric (TE) modules with annular geometry are very attractive for waste heat recovery within the automotive world, especially when integrated as stacks into tubular heat exchangers. The required temperature difference is built up between the coolant, which flows inside an inner tube, and the exhaust gas, which flows around an outer tube. The flow pattern of the exhaust gas can be axial or circumferential, which can lead to higher heat transfer coefficients on the outer surface of the tube. However, this multidimensional construction in combination with a complex flow pattern can lead to a nonuniform heat flux. Additionally, the system experiences a nonuniform temperature distribution which consequently leads to complex conditions regarding the electrical potential. The relevant effects are investigated using a three-dimensional (3-D) numerical model implemented in the computational fluid dynamics (CFD) simulation environment Star-CCM+. The model supports temperature-dependent characteristics of the materials, contact resistances, and parasitic effects in the TE module. Furthermore, it involves techniques to quickly find the exact maximum power point of the TE module with the given boundary conditions. Using the validated model the influence of the nonuniform temperature distribution is investigated with emphasis on the electrical output and TE efficiency.     

Active Ingredients in Individual Psychotherapy: Searching for Common Factors.

Every serious school of psychotherapy has its own theory--often only vaguely formulated--concerning the active ingredients in psychotherapy. Many of these theories are presented as mutually exclusive. The author presents an overview of some of the important, primarily psychoanalytically founded, theories of the factors in individual psychotherapy that are responsible for inducing change. It is impossible to pinpoint any single factor that is crucial in every therapy. What is needed is a nondogmatic, multiple-factor model that successfully incorporates the knowledge obtained from the many existing theories of psychotherapy-induced change. In practice, it is often difficult to maintain the traditional distinction between specific and nonspecific factors, just as it is difficult to distinguish the roles played by purely therapeutic factors--relating to the technique of the therapist--and by extratherapeutic factors. The author also addresses the epistemological status of the various claims put forward, by the many different theories of psychotherapy, concerning the active ingredients in psychotherapy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Diffusion coefficient of ferrocene in 1-butyl-3-methylimidazolium tetrafluoroborate - concentration dependence and solvent purity

The ionic liquid l-butyl-3-methylimidazolium tetrafluoroborate is used as electrolyte in the electrochemical determination of the diffusion coefficient of ferrocene as a function of concentration by cyclic voltammetry and chronoamperometry. An improved synthesis of the room temperature ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate is described, which yields a product of high purity suitable for electrochemical purposes. A qualitative color test is discussed which allows the simple detection of silver ion contaminations. The diffusion coefficient of ferrocene appears to be concentration dependent in the solvent chosen.