Der (ungerade) Collatz-Baum

Ohne Zusammenfassung     

Development of a technology orientated programming system for industrial robots

The disassembly of used goods is characterized by strongly varying quantities and a wide range of different kinds and states of products. Furthermore, the requirements of a disassembly system are determined by the disassembly object, by the process as well as by the disassembly system itself. As a result of the high labor costs in industrial countries and the huge amount of used goods, an automated disassembly is favored for the industrial disassembly. New methods for the programming of industrial robots have to be developed because the costs for a programming of small lot sizes are a key factor of the economic efficiency of small and medium sized enterprises (SME). In this paper an off-line programming environment for programming of industrial robots in the field of automated disassembly is presented. The exemplary implementation is realized at a pilot disassembly system, which was built up at the Institut für Werkzeugmaschinen und Fabrikbetrieb (IWF) of the Technische Universität Berlin.     

Automated multiscale morphometry of muscle disease from second harmonic generation microscopy using tensor-based image processing

Practically, all chronic diseases are characterized by tissue remodeling that alters organ and cellular function through changes to normal organ architecture. Some morphometric alterations become irreversible and account for disease progression even on cellular levels. Early diagnostics to categorize tissue alterations, as well as monitoring progression or remission of disturbed cytoarchitecture upon treatment in the same individual, are a new emerging field. They strongly challenge spatial resolution and require advanced imaging techniques and strategies for detecting morphological changes. We use a combined second harmonic generation (SHG) microscopy and automated image processing approach to quantify morphology in an animal model of inherited Duchenne muscular dystrophy (mdx mouse) with age. Multiphoton XYZ image stacks from tissue slices reveal vast morphological deviation in muscles from old mdx mice at different scales of cytoskeleton architecture: cell calibers are irregular, myofibrils within cells are twisted, and sarcomere lattice disruptions (detected as "verniers") are larger in number compared to samples from healthy mice. In young mdx mice, such alterations are only minor. The boundary-tensor approach, adapted and optimized for SHG data, is a suitable approach to allow quick quantitative morphometry in whole tissue slices. The overall detection performance of the automated algorithm compares very well with manual "by eye" detection, the latter being time consuming and prone to subjective errors. Our algorithm outperfoms manual detection by time with similar reliability. This approach will be an important prerequisite for the implementation of a clinical image databases to diagnose and monitor specific morphological alterations in chronic (muscle) diseases.     

Effective electrical conductivity of nanocomposites. Influence of image forces on contact conductivity of metal‐filled polymer nanocomposites

The generalized effective conductivity of a heterogeneous medium with chaotic structure is defined based on the ideas of the renormalization group transformation method and the theory of fractals. The fractal sets obtained from rectangular lattices have been used to construct the structure of a nanocomposite with random distribution of components (phases). A model for the calculation of effective electrical conductivity of filled polymer nanocomposites is developed. It is based on conductivity between two filler particles separated by matrix polymer as an elementary conductivity event and the application of an iterative averaging method. The comparison of the calculation and experimental data of different filled polymer systems shows good agreement. PACS: 72.80 Tm; 72.60+ g; and 84.32 Ff. POLYM. COMPOS., 31:1541–1553, 2010. © 2009 Society of Plastics Engineers     

DEVELOPMENT OF RANEY-TYPE LOW TEMPERATURE METHANOL SYNTHESIS CATALYSTS†

Catalysts prepared by caustic leaching of Cu—Zn—Al alloys are shown to have activities greater than those of a commercial copper-based catalyst.

Complete leaching of alloys containing 50 wt.% aluminium, with between 0 and 50 wt.% copper, and the balance zinc produced catalysts having a wide range of activities. The most active catalysts for methanol production were produced from alloys containing from 10 to 20 wt.% zinc.

The activities of catalysts prepared by the partial leaching of an alloy containing approximately 36% copper, 15% zinc and 48% aluminium were shown to pass through a maximum at a leaching time of 2.75 hours. This catalyst had more than double the activity of a commercial catalyst al reaction conditions similar to those employed industrially.     

Direct Hydrogenolysis of Highly Concentrated Glycerol Solutions Over Supported Ru,Pd and Pt Catalyst Systems

Abstract  

The evaluation of supported precious metal catalysts, in combination with and without solid acids, for the hydrogenolysis of highly concentrated glycerol solutions, with the aim to produce lower alcohols, in particular 1-propanol was studied. GCMS analysis of the product mixtures obtained has shed some light on the possible mechanism leading to unwanted condensation products, as well as the composition of these compounds.     

Growth processes in a cascade of bioreactors: Mathematical models

Mathematical modeling of continuous multiple bioreactors is complicated by two factors. First, the chemical environments differ in different reactors, so biomass receives an environmental shock when it is transferred between reactors. Second, biomass occurs as discrete cells, which of course are and remain segregated from one another, so an element of biomass that enters a reactor does not mix with the biomass already present. This differs from the behavior of an element of liquid which enters a reactor in that such an element quickly mixes with the liquid already present. The biomass in a bioreactor receiving biomass from an external source is therefore heterogeneous with respect to the history of environmental conditions and composition. This article shows how to construct a mathematical model of multiple bioreactor apparatus that accounts for these complications. It also describes simpler models that do not account for both of them.     

Volatile Foraging Kairomones in the Littoral Zone: Attraction of an Herbivorous Freshwater Gastropod to Algal Odors

Volatile organic compounds (VOCs) produced by algae and cyanobacteria are primarily responsible for odors in fresh waters. Among other functions, VOCs may serve as important infochemicals in biofilms of benthic primary producers. VOCs liberated by benthic, mat-forming cyanobacteria can be used as habitat-finding cues by insects, nematodes, and possibly other organisms. We developed a new gastropod behavioral assay that allows detection of food preference without offering food, thus allowing the distinction between taste, which requires direct contact with the food source, and the detection of odorous infochemicals, which work over distance. We demonstrated that VOCs released from disintegrated cells of a benthic, mat-forming, green alga (Ulothrix fimbriata) are food-finding cues (“foraging kairomones”) that attract the herbivorous freshwater snail Radix ovata. A mixture of three C₅ lipoxygenase compounds and 2(E),4(E)-heptadienal that mimic the major VOCs released by U. fimbriata attracted the snails, whereas neither the mixture of C₅ compounds nor 2(E),4(E)-heptadienal were effective when given alone. This study suggests that VOCs can play a steering role as infochemicals in freshwater benthic habitats, as has been established for many organismic interactions in terrestrial ecosystems.