Efficient assessment of noise transmission through highly flexible slender structures

In this work, we propose an efficient methodology for the assessment of noise transmission through cables and hoses. An interactive simulation with a geometrically exact Cosserat rod enables simple and fast modelling of various configurations. Subsequently, we linearise the equations of motion at the static equilibrium for given boundary conditions and, using the resulting system matrices, compute the mechanical impedance matrix. The computation result, i.e. the impedance matrix, is available within seconds. The impedance matrix either can be used to compute reaction forces for given excitation or, if the excitation is unknown, allows to analyse the transmission of noise by looking at single matrix elements. The latter is especially useful in early, purely virtual development phases

Crystallographic order and decomposition of [MnIII6CrIII]3+ single-molecule magnets deposited in submonolayers and monolayers on HOPG studied by means of molecular resolved Atomic Force Microscopy (AFM) and Kelvin Probe Force Microscopy in UHV

Gryzia A, Volkmann T, Brechling A, et al. Crystallographic order and decomposition of [MnIII6CrIII]3+ single-molecule magnets deposited in submonolayers and monolayers on HOPG studied by means of molecular resolved Atomic Force Microscopy (AFM) and Kelvin Probe Force Microscopy in UHV. Nanoscale Research Letters. 2014;9(1): 60.Monolayers and submonolayers of [MnIII6CrIII]3+ single-molecule magnets (SMMs) adsorbed on highly oriented pyrolytic graphite (HOPG) using the droplet technique characterized by non-contact atomic force microscopy (nc-AFM) as well as by Kelvin probe force microscopy (KPFM) show island-like structures with heights resembling the height of the molecule. Furthermore, islands were found which revealed ordered 1D as well as 2D structures with periods close to the width of the SMMs. Along this, islands which show half the heights of intact SMMs were observed which are evidences for a decomposing process of the molecules during the preparation. Finally, models for the structure of the ordered SMM adsorbates are proposed to explain the observations

Characterization of multifunctional β-NaEuF4/NaGdF4 core–shell nanoparticles with narrow size distribution

We characterized NaEuF4/NaGdF4 core–shell nanoparticles

Stainless steel made to rust: a robust water-splitting catalyst with benchmark characteristics

The oxygen evolution reaction (OER) is known as the efficiency-limiting step for the electrochemical cleavage of water mainly due to the large overpotentials commonly used materials on the anode side cause. Since Ni–Fe oxides reduce overpotentials occurring in the OER dramatically they are regarded as anode materials of choice for the electrocatalytically driven water-splitting reaction. We herewith show that a straightforward surface modification carried out with AISI 304, a general purpose austenitic stainless steel, very likely, based upon a dissolution mechanism, to result in the formation of an ultra-thin layer consisting of Ni, Fe oxide with a purity >99%. The Ni enriched thin layer firmly attached to the steel substrate is responsible for the unusual highly efficient anodic conversion of water into oxygen as demonstrated by the low overpotential of 212 mV at 12 mA cm−2 current density in 1 M KOH, 269.2 mV at 10 mA cm−2 current density in 0.1 M KOH respectively. The Ni, Fe-oxide layer formed on the steel creates a stable outer sphere, and the surface oxidized steel samples proved to be inert against longer operating times (>150 ks) in alkaline medium. In addition Faradaic efficiency measurements performed through chronopotentiometry revealed a charge to oxygen conversion close to 100%, thus underpinning the conclusion that no “inner oxidation” based on further oxidation of the metal matrix below the oxide layer occurs. These key figures achieved with an almost unrivalled-inexpensive and unrivalled-accessible material, are among the best ever presented activity characteristics for the anodic water-splitting reaction at pH 13

A process model of the formation of spatial presence experiences

In order to bridge interdisciplinary differences in Presence research and to establish connections between Presence and “older” concepts of psychology and communication, a theoretical model of the formation of Spatial Presence is proposed. It is applicable to the exposure to different media and intended to unify the existing efforts to develop a theory of Presence. The model includes assumptions about attention allocation, mental models, and involvement, and considers the role of media factors and user characteristics as well, thus incorporating much previous work. It is argued that a commonly accepted model of Spatial Presence is the only solution to secure further progress within the international, interdisciplinary and multiple-paradigm community of Presence research

Ordered Rape : A Principal–Agent Analysis of Wartime Sexual Violence in the DR Congo

Policy makers and academics often contend that organizational anarchy permits soldiers to perpetrate sexual violence. A recent United Nations report supports this thesis especially with regard to the massive sexual abuse in the Congolese civil war. We challenge the anarchy argument and maintain, based on a principal-agent framework, that opportunistic military commanders can order their soldiers to rape through the use of sanctions and rewards. Our qualitative and quantitative analysis of a survey of 96 Congolese ex-soldiers shows that ordered rape is more likely in organizations where soldiers fear punishment and in which commanders distribute drugs as stimulants

Cain´s choice : causes of one-sided violence against civilians

This article offers a survey of the literature on one-sided violence, focussing on strategic and organizational explanations of this phenonmenon. The authors discuss the circumstances under which international interventions are successful and reduce the death toll

Industrielle Prozesswärme im Kontext eines treibhausgasneutralen Energiesystems

Im Rahmen einer aktuellen Studie zur Transformation des Europäischen Energiesystems zur Klimaneutralität unter Berücksichtigung der Gaskrise entwickelte das Wuppertal Institut ein Szenario (EU27+UK) für die Transformation der europäischen Industrie inklusive Raffinerien und Kokereien, in dem die industriellen Treibhausgasemissionen bis zum Jahr 2050 um 99 % gegenüber 2018 gemindert werden. Der Endenergiebedarf der Industrie sinkt in diesem Szenario durch den Einsatz von Wärmepumpen, andere Energieeffizienzmaßnahmen sowie einen Rückgang der Produktion in Raffinerien bis 2040 deutlich und der Bedarf an fossilen Gasen kann zeitnah gemindert und bis 2045 auf nahezu Null gesenkt werden. Im Rahmen dieses Szenarios erfolgte auch eine detaillierte Abbildung der Entwicklung der Prozesswärmebereitstellung in Deutschland. Die Bereit- stellung von Niedertemperaturwärme (< 150 °C) erfolgt im Szenario größtenteils über Wärmepumpen und Fernwärme. Solar- und Geothermie spielen eine (kleinere) Rolle. Für die Dampfbereitstellung (150 - 500 °C) werden vielfach hybride Strom/H2-Kessel eingesetzt, daneben Biomasse. In der Chemieindustrie spielen auch langfristig Reststoffe aus Steamcrackern eine wichtige Rolle. Die Bereitstellung von Hochtemperaturwärme erfolgt prozessspezifisch je nach den technischen Gegebenheiten der Prozesse (z. B. H2 in den Direktreduktions- anlagen und Biomasse in den Walzwerken der Stahlindustrie, abfallbasierte Brennstoffe vor allem in den Klinkeröfen der Zementindustrie, Biomethan und Strom in der Glasindustrie, Strom für Primär- und Sekundäraluminium). Biogene Energieträger in Kombination mit CCS (BECCS) ermöglichen in der Stahlindustrie und in der mineralischen Industrie die Bereitstellung von Hochtemperaturwärme und gleichzeitig negative Emissionen zur Kompensation von Restemissionen

Riesz-projection based simulation and analysis of resonant photonic devices and machine-learning based parameter optimization

We present Riesz projection based methods relying on contour integration for efficiently computing quasi-normal modes and modal expansions of near-field and far-field physical quantities. We use a finite-element method based implementation of these methods for the analysis of nanophotonic resonators for quantumoptics applications. We use Bayesian optimization methods for finding best geometry parameters yielding, e.g., resonators with maximized quality factor