37 Works

Dissimilar titanium and titanium aluminide joints manufactured by laser beam welding and laser additive manufacturing

Irmela Burkhardt
Durch die zunehmenden Anforderungen an Leichtbaukonstruktionen motiviert, ist das Ziel ungleichartige Ti- und γ-TiAl-Ti-Legierungs-Verbindungen aus Blechen rissfrei mittels Laserstrahlschweißen herzustellen. Dies wurde durch Vorheizen erreicht. Die Rissentstehung konnte der Mikrostruktur-Phasen-Entwicklung zugeordnet werden. Der Einfluss der Grenzfläche auf den Versagensort und die Zugeigenschaften wurde durch Zugversuche ermittelt. Zudem wurde das gewonnene Wissen bezüglich der Mikrostruktur-Phasen-Entwicklung an der Grenzfläche erfolgreich auf laserauftragsgeschweißte Strukturen übertragen und die Grenzen der Übertragbarkeit bezüglich der Rissbildung aufgezeigt. Folglich wurden die Grundlagen...

Resilience through aroecology and ecological restoration : the system of rice intensification with intercropping

Tavseef Mairaj Shah & Ralf Otterpohl

Predicting long-term dynamics of soil salinity and sodicity on a global scale

Amirhossein Hassani, Adisa Azapagic & Nima Shokri
Knowledge of spatiotemporal distribution and likelihood of (re)occurrence of salt-affected soils is crucial to our understanding of land degradation and for planning effective remediation strategies in face of future climatic uncertainties. However, conventional methods used for tracking the variability of soil salinity/sodicity are extensively localized, making predictions on a global scale difficult. Here, we employ machine-learning techniques and a comprehensive set of climatic, topographic, soil, and remote sensing data to develop models capable of making...

On the potential of gassy marine soils triggering submarine slope instabilities

Pauline Kaminski & Jürgen Grabe
The development of debris flows and turbidity currents in the course of a submarine slope failure event can cause major damage in offshore infrastructure. Additionally, the tsunamogenic potential of large slope failures at continental margins poses a direct threat to coastal communities. Therefore, the trigger mechanisms of submarine slope failures have been thoroughly investigated in the past. However, the influence of free gas in the sediment, which has been observed close to several slide events,...

Agroecological engineering interventions in rice cultivation: food security and sustainable rural development in South Asia

Tavseef Mairaj Shah
Die ökologischen Folgen der industriellen Landwirtschaft und die rasante Erschöpfung der Boden- und Wasserressourcen machen ein Umdenken der Ernährungssysteme unerlässlich. Reis, das Grundnahrungsmittel für mehr als die Hälfte der Weltbevölkerung, kann dabei eine entscheidende Rolle spielen. Diese Arbeit liefert Argumente für agrarökologische Interventionen im Reisanbau, um die negativen Auswirkungen des Ernährungssystems zu mildern und nachhaltige Entwicklungsziele in ländlichen Gebieten zu erreichen. In diesem Zusammenhang wird über die im Rahmen von SRIBI (System of Rice Intensification...

Characterization and performance of LbL-coated multibore membranes : zeta potential, MWCO, permeability and sulfate rejection

Saskia Dillmann, Shambhavi Arvind Kaushik, Jakob Stumme & Mathias Ernst
The characterization of membranes is suitable to investigate changes in the membrane properties caused by Layer-by-Layer (LbL) modification. Besides permeability, rejection, and molecular-weight cut-off (MWCO), which give information about the modification of the separation behaviour of the membrane, the zeta potential is capable of describing the surface charge of the membrane and its variation impacted by the properties of the polyelectrolyte multilayers (PEM). In this study, a new method for zeta potential measurement of hollow...

Controlling the large-scale fabrication of supraparticles

Alexander Plunkett, Catriona Eldridge, Gerold A. Schneider & Berta Domènech Garcia
Controlling the nanoscale interactions of colloidal building blocks is a key step for the transition from single nanoparticles to tailor-made, architected morphologies and their further integration into functional materials. Solvent evaporation-induced self-assembly within emulsion droplets emerges as a fast, versatile, and low-cost approach to obtain spherical, complex structures, such as supraparticles. Nevertheless, some process-structure relationships able to describe the effects of emulsion conditions on the synthesis outcomes still remain to be understood. Here, we explore...

Building resilience to climate change induced extreme weather events through agriculture with a focus on the system of rice intensification

Tavseef M. Shah & Ralf Otterpohl
The temperate Himalayan valley of Kashmir is certainly not out of the sphere of influence of climate change induced irregular and extreme weather events. The effects of climate change have become more evident in recent years with drier winters and prolonged dry spells during the agricultural season, when rains are most needed for the crops. The catastrophic floods of September 2014, which led to complete destruction of the harvest-ready crops (mostly rice paddies) is fresh...

Influence of the experimental set-up and voltage ramp on the dielectric breakdown strength and breakdown site in borosilicate glass

Pia-Kristina Fischer & Gerold A. Schneider
The dielectric breakdown strength of borosilicate glass and alumina was measured as a function of the voltage ramp rate on different material thicknesses and with different electrode configurations. While this is not a completely new approach, with our work we want to highlight the importance of appropriate measurement set-up and contribute to a better understanding and analysis of dielectric breakdown. The measurement of breakdown tests is generally anything but trivial and the comparison of breakdown...

Agricultural resilience-sustainability and food security in South Asia in the context of changes in global climate

Tavseef Mairaj Shah & Ralf Otterpohl
One of the areas that is directly affected by the changes in global climate and involves the poorest of the world is agriculture and hence by association food security. Unsustainable farming practices like the excessive use of mineral fertilizers and plowing have further aggravated the situation, having led to an irreversible destruction of cultivable soils worldwide. In this regard, certain areas of South Asia have been described as among the regions most vulnerable to climate...

Precursor film spreading during liquid imbibition in nanoporous photonic crystals

Luisa G. Cencha, Guido Dittrich, Patrick Huber, Claudio L. A. Berli & Raul Urteaga
When a macroscopic droplet spreads, a thin precursor film of liquid moves ahead of the advancing liquid-solid-vapor contact line. Whereas this phenomenon has been explored extensively for planar solid substrates, its presence in nanostructured geometries has barely been studied so far, despite its importance for many natural and technological fluid transport processes. Here we use porous photonic crystals in silicon to resolve by light interferometry capillarity-driven spreading of liquid fronts in pores of few nanometers...

Data for Publication Exploring key ionic interactions for magnesium degradation in simulated body fluid - a data-driven approach

Berit Zeller-Plumhoff, Melissa Gile, Melissa Priebe, Hanna Slominska, Benjamin Boll, Björn Wiese, Tim Würger, Regine Willumeit-Römer & Robert Horst Meißner
This is the readme file for all data used within the publication "Exploring key ionic interactions for magnesium degradation in simulated body fluid - a data-driven approach" Created: 25th January 2020 by Dr. Berit Zeller-Plumhoff Contact: berit.zeller-plumhoff@hzg.de The publication is based on a number of experimental and computational data sets. These are: - microCT imaging data (raw and processed) before and after degradation - Fiji/ImageJ scripts for automated processing and read-out of the imaging data...

Analysis of the German industry to determine the resource potential of CO2 emissions for PtX applications in 2017 and 2050

Tjerk Zitscher, Ulf Neuling, Antoine Habersetzer & Martin Kaltschmitt
The production and use of crude oil-based materials, e.g., fossil fuels and bulk chemicals of organic origin, results in an increasing level of CO2 emissions within the atmosphere. One way to reduce such CO2 emissions is to substitute them with synthetic fuels and bulk chemicals. For the production of such CO2 neutral materials, CO2 from various sources can serve as a carbon source. Against this background, this paper analyses and quantifies CO2 emissions released from...

Compilation for real-time systems a decade after predator

Heiko Falk, Shashank Jadhav, Arno Luppold, Kateryna Muts, Dominic Paul Oehlert, Nina Piontek & Mikko Julian Roth
On the occasion of Peter Marwedel’s 70th anniversary, this article provides a survey over a decade of research in the field of compiler techniques for real-time systems. Ten years ago, during the EU-funded project Predator, it was him who led the work package on compilers. As will be shown in this survey, the work done in this domain had such a fundamental character that it laid the ground for follow-up research that lasts since the...

Modeling eelgrass spatial response to nutrient abatement measures in a changing climate

Ivo Christian Bobsien, Wolfgang Hukriede, Christian Schlamkow, René Friedland, Norman Dreier, Philipp Schubert, Rolf Karez & Thorsten B. H. Reusch
For many coastal areas including the Baltic Sea, ambitious nutrient abatement goals have been set to curb eutrophication, but benefits of such measures were normally not studied in light of anticipated climate change. To project the likely responses of nutrient abatement on eelgrass (Zostera marina), we coupled a species distribution model with a biogeochemical model, obtaining future water turbidity, and a wave model for predicting the future hydrodynamics in the coastal area. Using this, eelgrass...

Design of personalized devices—the tradeoff between individual value and personalization workload

Juliane Kuhl, Andreas Ding, Ngoc Tuan Ngo, Andrés Braschkat, Jens Fiehler & Dieter Krause
Personalized medical devices adapted to the anatomy of the individual promise greater treatment success for patients, thus increasing the individual value of the product. In order to cater to individual adaptations, however, medical device companies need to be able to handle a wide range of internal processes and components. These are here referred to collectively as the personalization workload. Consequently, support is required in order to evaluate how best to target product personalization. Since the...

Submillimeter-Accurate Marker Localization within Low Gradient Magnetic Particle Imaging Tomograms

Florian Griese, Tobias Knopp, René Werner, Alexander Schlaefer & Martin Möddel
Magnetic Particle Imaging (MPI) achieves a high temporal resolution, which opens up a wide range of real-time medical applications such as device tracking and navigation. These applications usually rely on automated techniques for finding and localizing devices and fiducial markers in medical images. In this work, we show that submillimeter-accurate automatic marker localization from low gradient MPI tomograms with a spatial resolution of several millimeters is possible. Markers are initially identified within the tomograms by...

Supply chain sustainability performance indicators-A systematic literature review

Muhammad Amad Saeed & Wolfgang Kersten
This research article aims to identify sustainability performance indicators (SPIs) and provide practical guidance for assessing organizations and their supply chains’ sustainability-related performances. We conducted a systematic literature review to analyze scientific journal articles related to sustainable supply chains and performance measurement. We assessed sustainability performance by identifying 1054 indicators from selected scientific journal articles. In addition, in-depth analyses of selected journal articles, predefined attribute categories, and the text restructuring resulted in a unique and...

Three dimensional flows beneath a thin layer of 2D turbulence induced by Faraday waves

Raffaele Colombi, Michael Schlüter & Alexandra von Kameke
Abstract: Faraday waves occur on a fluid being subject to vertical shaking. Although it is well known that form and shape of the wave pattern depend on driving amplitude and frequency, only recent studies discovered the existence of a horizontal velocity field at the surface, called Faraday flow. This flow exhibits attributes of two-dimensional turbulence and is replicated in this study. Despite the increasing attention towards the inverse energy flux in the Faraday flow and...

Korrosionssimulation von pressgehärteten Stählen und Filiformfäden auf Aluminium

Tom Gießgen
Ein Simulationsmodell für die Vorhersage von Korrosionsschäden an lackierten pressgehärteten Stählen und Aluminium, wie sie beispielsweise in Pkw-Karosserien verwendet werden, wird entwickelt. Dazu werden die Eigenschaften der metallischen Phasen und Lackschichten mit metallografischen und elektrochemischen Methoden (Polarisationskurven, galvanostatische Auflösung, Impedanzspektroskopie) untersucht. Ein neuer Ansatz zur Beschreibung des Einflusses der Korrosionsprodukte auf den Korrosionsfortschritt wird präsentiert.

Climate impact mitigation potential of formation flight

Tobias Marks, Katrin Dahlmann, Volker Grewe, Volker Gollnick, Florian Linke, Sigrun Matthes, Eike Stumpf, Majed Swaid, Simon Unterstrasser, Hiroshi Yamashita & Clemens Zumegen
The aerodynamic formation flight, which is also known as aircraft wake-surfing for efficiency (AWSE), enables aircraft to harvest the energy inherent in another aircraft’s wake vortex. As the thrust of the trailing aircraft can be reduced during cruise flight, the resulting benefit can be traded for longer flight time, larger range, less fuel consumption, or cost savings accordingly. Furthermore, as the amount and location of the emissions caused by the formation are subject to change...

IVOCT catheter tracking and targeted drug delivery using magnetic particle imaging and magnetic particle navigation

Florian Griese
Magnetic-Particle-Imaging (MPI) visualisiert die quantitative Verteilung von magnetischen Nanopartikeln mit statischen und oszillierenden Magnetfeldern. In dieser Arbeit wird eine submillimetergenaue Lokalisierungsmethode entwickelt, um Markierungen für die Registrierung von MRT- und MPI-Volumen zu identifizieren. Mit dieser Methode wird auch ein IVOCT-Katheter in 4D bimodal mit MPI verfolgt. Des Weiteren werden Magnetic-Particle-Imaging und Magnetic-Particle-Navigation verwendet, um magnetische Partikel durch eine Verzweigung zu navigieren. Zuletzt wird die easy-axis-Orientierung von Proben mit dem neuartigen easy-axis-aligned-MPI-Kontrast bestimmt.

Taper corrosion: a complication of total hip arthroplasty

Michael Morlock, Robert Hube, Georgi Iwan Wassilew, Felix Prange, Gerd Huber & Carsten Perka
This article is distributed under the terms of the Creative Commons Attribution-Non Commercial 4.0 International (CC BY-NC 4.0) licence (https://creativecommons.org/licenses/by-nc/4.0/) which permits non-commercial use, reproduction and distribution of the work without further permission provided the original work is attributed. The focus on taper corrosion in modular hip arthroplasty increased around 2007 as a result of clinical problems with large-head metal-on-metal (MoM) bearings on standard stems. Corrosion problems with bi-modular primary hip stems focused attention on...

Modelling of flood inundation due to levee breaches : sensitivity of flood inundation against breach process parameters

Yohannis Birhanu Tadesse & Peter Fröhle
This paper analyses the sensitivity of flood inundation due to river levee breach against breach process parameters using the 1996 Awash River levee breach case at Wonji, Ethiopia. A parametric levee breach model integrated into the 2D hydrodynamic numerical model Telemac-2D is used to simulate a levee breach flood event at Wonji, Ethiopia. Levee breach process parameters are systemically varied to find out their effect on the flood inundation. The analysis of the model results...

Visualization of spatial and temporal temperature distributions with magnetic particle imaging for liver tumor ablation therapy

Johannes Salamon, Jan Henrik Dieckhoff, Michael Kaul, Caroline Jung, Gerhard Adam, Martin Möddel, Tobias Knopp, Sebastian Draack, Frank Ludwig & Harald Ittrich
Temperature-resolved magnetic particle imaging (MPI) represents a promising tool for medical imaging applications. In this study an approach based on a single calibration measurement was applied for highlighting the potential of MPI for monitoring of temperatures during thermal ablation of liver tumors. For this purpose, liver tissue and liver tumor phantoms embedding different superparamagnetic iron oxide nanoparticles (SPION) were prepared, locally heated up to 70 °C and recorded with MPI. Optimal temperature MPI SPIONs and...

Registration Year

  • 2021
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