3,766 Works

Entwicklung einer Simulationsmethodik zur schnellen Dimensionierung komplexer Materialflusssysteme

Svenja Bahnsen, Harald Köck, Johannes Hinckeldeyn & Jochen Kreutzfeldt
Simulation models play an important role in the planning and development in intralogistics. Especially the layout and dimensioning of order picking processes, warehouses and handling engineering is often based on static estimations and rules of thumb. This leads to inferior planning results, because dynamic effects, such as peaks of orders, and sequential process steps are often neglected. The most common solution at the moment are event discrete simulation models, which create a significant workload for...

Dealloying progress during nanoporous structure evolution analyzed by In situ resistometry

Eva-Maria Steyskal, Michael Seidl, Matthias Graf & Roland Würschum
The progress of dealloying, an electrochemical synthesis method capable of producing nanoporous structures with bulk outer dimensions, is studied by in situ resistometry. The resistance increases by three orders of magnitude while nanoporous gold or platinum is formed. Simultaneous monitoring of charge flow and electrical resistance increase proves to be an ideal combination for analyzing the etching progress, which in accordance with recent studies can be demonstrated to occur in two steps referred to as...

An external calibration system for DBF receiver arrays at Ka-band

Minh Nhat Pham
In der vorliegenden Arbeit wird ein Online-Kalibrierverfahren mit an-Bord Sonden für DBF Empfangssysteme entwickelt. Das sogenannte externe Konzept ist nicht nur für die Kalibrierung der Kanalschwankungen entwickelt aber auch für die Kalibrierung der Kanal-schwankungen und –Kopplung erweitert. Die Anwendbarkeit des Kalibrierkonzepts ist durch Experimente in Labor demonstriert.

Reclaiming biologically pretreated greywater for reuse by photocatalytic oxidation: qualitative study on the removal of trace organics

Holger Gulyas, Carlos F. Liriano Jorge, Margrit Reich & Ralf Otterpohl
This study was carried out for gathering qualitative information about the potential of photocatalytic oxidation for the removal of trace organics (analysed by gas chromatography coupled to mass spectrometry, GC/MS) from biologically pretreated greywater to make it suitable for high quality reuse applications like groundwater recharge. Additionally, fractions of bulk organics (humic substances, building blocks, and low molecular weight organic acids) were quantified by liquid chromatography with organic carbon detection. Biologically pretreated greywater was subjected...

M02.010 Determination of settleable matter

Tanja Millfahrt & Alina Stahl
This method describes the determination of settleable matter by volume in water and waste water (see DIN 38409-9).

M03.005 Qualitative and quantitative determination of saponins by LC-MSTOF and LC-MS/MS

Alina Stahl & Heike Frerichs
Mit der vorliegenden Methode können die Ginsenoside Panaxatriol, Panaxadiol, Rb1, Rd, Rg3, Rh2, Compound K und F2, sowie die beiden Sojasaponine Aa und Bb in enzymatisch behandelten Soja- oder Ginsengextrakten quantitativ erfasst werden. Die quantitative Messung verschiedener Saponine (aktuell z.B. Rg1, Rb1, Panaxatriol und Panaxadiol) erfolgt mittels LC-MSMS (Sciex Qtrap 5500) mit einer Luna C18-Säule in positiver und negativer Polarität (gleichzeitig). Die Auswertung erfolgt über eine externe Kalibrierung mit Integration der Peakfläche. Sollen andere Saponin-Abbauprodukte...

Experimental and analytical investigation of cemented tungsten carbide ultra-short pulse laser ablation

Juan Pablo Calderón Urbina, Christian Daniel & Claus Emmelmann
Ultra-short pulse laser processing of hard materials, such as cemented tungsten carbide, requires an accurate and agile experimental and analytical investigation to obtain adequate information and setting parameters to maximize ablation rate. Therefore, this study presents a systematic approach which, first, experimentally searches for the variables with the most significant influence on the objective using a design of experiments method; and second, analyzes by means of existing ablation theory the interaction of the material and...

Overall process analysis and optimisation for CO₂ capture from coal fired power plants based on phase change solvents forming two liquid phases

Ulrich Liebenthal, Diego D. D. Pinto, Juliana G. M.-S. Monteiro, Hallvard F. Svendsen & Alfons Kather
In this work the potential of a novel post-combustion CO₂ capture process is analysed with respect to the integrated overall process. As solvent a blend of two amines (DEEA/MAPA) which forms two liquid phases under CO₂ loading is used. The two phases have distinct physical characteristics. Only the heavy phase, rich in CO₂ loading, is led to the desorber. The novel solvent combination promises very low energy consumption compared to a 30 wt.-% MEA solution....

High-rate nitrification of membrane-filtrated saline landfill leachate using fixed-bed biofilm reactors

Sreenivasan Ramaswami
Alleine durch Umkehrosmose (UO) kann hochammoniumhaltigen Deponiesickerwässer nicht ausreichend behandelt werden. Die mehrstufige Hochdruckmembrananlage (inklusiv UO und Nanofiltration (NF) Verfahren) für die Sickerwasseraufbereitung in Deponie Ihlenberg ergibt sich ein unzureichender Ammoniumrückhalt. In dieser Arbeit wurde die Nitrifikation in belüfteten Festbettreaktoren untersucht, um dieses Problem zu lösen. Mit dem NF-Permeat des UO-Retentats des Rohsickerwassers (mit 16 g/L Cl-, 45 mS/cm) wurden Nitrifikationseffizienzen über 97% bei Volumenbelastungsraten von ca. 1100 g NH4+-N/(m3∙d) bei 25°C erreicht. Basierend der...

Compilation for real-time systems : an overview of the WCET-aware C compiler WCC

Dominic Paul Oehlert, Arno Luppold & Heiko Falk
Traditionell finden Design und zeitliche Analyse eines eingebetteten harten Echtzeitsystems getrennt voneinander statt. Dies führt zu einem komplexen Designfluss, der menschliche Interaktion benötigt. Weiter optimieren Standardcompiler in Bezug auf die durchschnittliche Performanz, so dass der Systemdesigner nicht bei der Optimierung hinsichtlich der schlimmstmöglichen Programmlaufzeit unterstützt wird. Der WCET-Aware C Compiler WCC verbessert diese Situation, indem Planbarkeitsanalysen eng in den Compilierungs- und Optimierungsprozess mit eingebuden werden. Weiter bietet der Compiler gezielte Möglichkeiten um echtzeitbewusst Optimierungen durchzuführen...

Development of a scalable method for the efficient simulation of flows using dynamic goal-oriented local grid-adaptation

Manuel Manzke
Zur effizienten Simulation von maritimen Strömungen wurde ein Verfahren zur lokalen dynamischen Gitter Adaption in ein paralleles Berechnungsverfahren, welches auf dem Druckkorrekturalgorithmus basiert und unstrukturierte Gitter nutzt, integriert. Es wurden verschiedene Verfeinerungs-Indikatoren implementiert, angefangen bei Strömungsmerkmal-basierten bis hin zu ziel-orientierten Fehler Abschätzungen, welche aus der adjungierten Lösung des primalen Strömungsproblems gewonnen werden. Die Effizienz der Simulation von freien Oberflächen Strömungen wurde durch ein explizites Verfahren zu Schärfung der Grenzfläche, welches auf existierende VoF Methoden angewendet...

School locations and traffic Emissions — Environmental (In) justice findings using a new screening method

Philine Gaffron & Deb Niemeier
It has been shown that the location of schools near heavily trafficked roads can have detrimental effects on the health of children attending those schools. It is therefore desirable to screen both existing school locations and potential new school sites to assess either the need for remedial measures or suitability for the intended use. Current screening tools and public guidance on school siting are either too coarse in their spatial resolution for assessing individual sites...

Tetrabromidocuprates(II)—synthesis, structure and EPR

André Zabel, Alette Winter, Alexandra Kelling, Uwe Schilde & Peter Strauch
Metal-containing ionic liquids (ILs) are of interest for a variety of technical applications, e.g., particle synthesis and materials with magnetic or thermochromic properties. In this paper we report the synthesis of, and two structures for, some new tetrabromidocuprates(II) with several “onium” cations in comparison to the results of electron paramagnetic resonance (EPR) spectroscopic analyses. The sterically demanding cations were used to separate the paramagnetic Cu(II) ions for EPR measurements. The EPR hyperfine structure in the...

Building-linked location-based Instantaneous services system

Julian Ohrt & Volker Turau

A New Integrated Lab-on-a-Chip System for Fast Dynamic Study of Mammalian Cells under Physiological Conditions in Bioreactor

Janina Stephanie Bahnemann, Negar Rajabi, Grischa Fuge, Oscar Platas Barradas, Jörg Müller, Ralf Pörtner & An-Ping Zeng
For the quantitative analysis of cellular metabolism and its dynamics it is essential to achieve rapid sampling, fast quenching of metabolism and the removal of extracellular metabolites. Common manual sample preparation methods and protocols for cells are time-consuming and often lead to the loss of physiological conditions. In this work, we present a microchip-bioreactor setup which provides an integrated and rapid sample preparation of mammalian cells. The lab-on-a-chip system consists of five connected units that...

Towards sustainable development by new town planning : case study of Mazandaran Province of Iran

Ali Zahedi
Das New-Town-Planungskonzept wurde als alternative Lösung zur Regulierung des Stadt-Land-Wachstums in der iranischen Provinz Mazandaran übernommen. Die Forschung wurde in drei Hauptaspekten durchgeführt. Erstens, lokale Entwicklung durch die Gründung von Kleinunternehmen mit Low-Tech-Lösungen. Zweitens, das menschliche Wohlbefinden Beurteilung im Kandelous Dorf durch die Berücksichtigung von Wohnen, Einkommen und Arbeit, Work-Life-Balance, Bildung, Umweltqualität, Gesundheit, bürgerschaftliches Engagement und Governance, persönliche Sicherheit, soziale Zusammenhänge, Glück und Themen der Lebenszufriedenheit, Drittens , das Studiengebiet ist ein guter Ort, um...

A holistic approach for low cost heliostat fields

Andreas Pfahl, Michael Randt, Florian Meier, Martin Zaschke, Chris Geurts & Michael Buselmeier
The AutoR-project takes a holistic approach to reduce the cost of heliostat fields: Wireless control and energy supply enables to use smaller heliostats which need less steel per mirror area (but usually have high wiring cost). A low cost but high efficient drive system is chosen which reduces energy consumption to a minimum amount and leads to low cost for PV cell and energy storage. The usual boundary layer wind tunnels tests for heliostats are...

Artificial intelligence and digital transformation in supply chain management : innovative approaches for supply chains

This volume contains research contributions by an international group of authors addressing innovative and technology-based approaches for logistics and supply chains. They present business models and investment options for enhanced strategic decision making as well as recent approaches for supply chain analytics and risk management. This volume, edited by Wolfgang Kersten, Thorsten Blecker and Christian Ringle, provides valuable insights into the digitalization of Supply Chain Management and Logistics with regard to: Innovation and Technology Management,...

SmartAirCargoTrailer : autonomous short distance transports in air cargo

Benjamin Bierwirth, Ulrich Schwanecke, Thomas Gietzen, Daniel Andrés Lopéz & Robert Brylka
Purpose: SmartAirCargoTrailers improve short-distance air cargo transports within airport premises. They create real-time-transparency between the partners in the transport chain and thereby reduces waiting times while at the same time increasing equipment utilization. An autonomous truck with swap bodies facilitates these short-distance transports. Methodology: The SmartAirCargoTrailer system consist of an autonomous truck with swap trailers which is controlled by a cloud platform. To allow for real-timetransparency all shipments loaded onto the trailer are detected by...

Algorithm for situation-dependent adaptation of velocity for shuttle based systems

Thomas Kriehn, Franziska Schloz, Robert Schulz & Markus Fittinghoff
Purpose: Shuttle based storage and retrieval systems (SBS/RS) are suitable for applications which require a high throughput. Many times, however, the maximum performance of SBS/RS is not required. For example, when customers initiate a large number of retrieval requests at a specific time, or when a large number of storage requests enter the system at fixed times due to scheduled inbound deliveries. This article presents and discusses an algorithm that is based on closed-loop-control. Methodology:...

Can gamification reduce the shortage of skilled logistics personnel?

Florian Hofbauer & Lisa-Maria Putz
Purpose: The logistics sector faces a worldwide shortage of skilled personnel. Gamification represents a new approach to attract people's interest by applying game elements in a non-game context. In our study, we develop a theoretical framework to improve the image of the logistics sector using gamification for future studies. Methodology: Based on the findings of the literature review, we discuss gamification and its potential to improve the image of the logistics sector. Moreover, the core...

Blockchain adoption at German logistics service providers

Oliver Kühn, Axel Jacob & Michael Schüller
Purpose: The study provides a recent overview of the diffusion of blockchain technology in the logistics industry. It reveals the adoption of blockchain technology at German logistics service providers (LSPs) and their expectations regarding the future relevance of the technology. Based on the TOE Framework adoption supporting and inhibiting factors are identified. Methodology: In a first step, LSPs listed in the “Die Top 100 der Logistik 2016/2017” were contacted and questioned about their blockchain activities....

Smart risk analytics design for proactive early warning

Katharina Diedrich & Katja Klingebiel
Purpose: Automobile manufacturers are highly dependent on supply chain performance which is endangered by risks. They are not yet able to proactively manage these risks, often requiring reactive bottleneck management. A proactive and digitalized early warning method is needed. Methodology: The publication provides methodological-empirical contribution to proactive early warning resulting in a smart risk management approach. The methodological approach is carried out according to the design science research approach. Findings: The developed smart risk management...

Active strain-sensing with a nanoporous-metal hybrid material

Charlotte Kuss
In dieser Arbeit werden die ersten aktiven Dehnungs-Sensorikmessungen mit einen nanoporösen Metall-Hybridmaterial vorgestellt. Die hier hergeleitete thermodynamische Beziehung zwischen elastischen Eigenschaften, sowie Sensorik- und Aktorikparametern weist eine gute Übereinstimmung zwischen Experiment und Theorie auf. Diese Klasse von Materialien verhält sich phänomenologisch wie die der Piezokeramiken, obwohl die zugrundeliegenden Mechanismen völlig verschieden sind.

Simulation-based optimization at container terminals: a literature review

Marvin Kastner, Hannah Pache & Carlos Jahn
Purpose: While simulation-based optimization has been discussed in theory and practically employed at container terminals, the different publications in this field have not yet been presented and compared in a structured manner. This paper gathers the latest developments and examine the similarities and differences of the provided approaches. Furthermore, research gaps are identified. Methodology: The recent literature of simulation-based optimization on container terminals is examined using a mapping review approach. Emphasis is laid on the...

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