135 Works

Improvement of the process stability of arylmalonate decarboxylase by immobilization for biocatalytic profen synthesis

Miriam Aßmann, Carolin Mügge, Sarah Katharina Gaßmeyer, Junichi Enoki, Lutz Hilterhaus, Robert Kourist, Andreas Liese & Selin Kara
The enzyme arylmalonate decarboxylase (AMDase) enables the selective synthesis of enantiopure (S)-arylpropinates in a simple single-step decarboxylation of dicarboxylic acid precursors. However, the poor enzyme stability with a half-life time of about 1.2 h under process conditions is a serious limitation of the productivity, which results in a need for high catalyst loads. By immobilization on an amino C2 acrylate carrier the operational stability of the (S)-selective AMDase variant G74C/M159L/C188G/V43I/A125P/V156L was increased to a half-life...

Forwarding strategies for 6LoWPAN-fragmented IPv6 datagrams

Andreas Weigel
Diese Arbiet untersucht verschiedene Implementierungsstrategien für den Weiterleitungsaspekt des 6LoWPAN protocols für „low power and lossy networks“ (LLNs). Die Leistungsfähigkeit in Hinblick auf Latenz und Zuverlässigkeit wird für das LLN-typische Datensammlung- Verkehrsmuster für direkte und reassemblierende Strategien untersucht. Ein neuartiger Ansatz basierend auf Lauschen und dem Aussetzen von Transmissionen wird entwickelt und es wird gezeigt, dass dieser die Ende-zu-Ende-Zuverlässigkeit in einem Großteil der untersuchten Simulationsszenarien und Testnetzwerken signifikant verbessert.

BDD-based value analysis for X86 executables

Sven Mattsen
Wir präsentieren eine abstrakte Domäne zur Ganzzahlanalyse, die für maschinennahen Code, wo Präzision besonders wichtig ist, geeignet ist. Ganzzahlanalysen approximieren Ganzzahlmengen normalerwise durch konvexe Mengen, wobei Präzision verloren geht, aber Effizienz gewonnen wird. Unsere Ganzzahlanalyse basiert auf modifizierten binären Entscheidungsbäumen (BDD), die ein effizientes Speichern von Ganzzahlmengen ermöglichen. Die zugehörigen Transferfunktionen definieren wir auf der Struktur der BDDs, was sie selbst für sehr große Mengen effizient macht. Wir stellen die Domäne in Form einer Bibliothek...

Structural and differential analysis for program comprehension of executables

Arne Wichmann
Wir führen eine strukturelle Analyse (StA), die Schlüsselstellen für das Programmverständnis von ausführbaren Programmen identifiziert, und eine differenzielle Analyse (DiA), die Ähnlichkeiten zwischen solchen ausführbaren Programmen identifiziert, ein. Unsere StA basiert auf einer neuen Abstraktion von Kontrollflussinformationen auf Statementebene zu einer Repräsentation mit einer graphischen Ansicht, die eine intuitive Identifizierung von mitgelieferten Mustern ermöglicht. Unsere DiA basiert auf Sequenzalignments und benötigt nur die Position und Größe der Funktionen. Wir validieren die StA manuell mit einer...

PGE production in Southern Africa, part II: Environmental aspects

Benedikt Buchspies, Lisa Thormann, Charles Mbohwa & Martin Kaltschmitt
Platinum group elements (PGEs, 6E PGE = Pt + Pd + Rh + Ru + Ir + Au) are used in numerous applications that seek to reduce environmental impacts of mobility and energy generation. Consequently, the future demand for PGEs is predicted to increase. Previous studies indicate that environmental impacts of PGE production change over time emphasizing the need of up-to-date data and assessments. In this context, an analysis of environmental aspects of PGE production...

PGE production in Southern Africa, part I: Production and market trends

Lisa Thormann, Benedikt Buchspies, Charles Mbohwa & Martin Kaltschmitt
Platinum group elements (PGEs) are an important resource for many applications, such as automotive catalytic converters for vehicles, jewelry, electrical devices and as catalysts in the chemical and petroleum industries. At present, the greatest share of global PGE supply is extracted from the South African Bushveld Complex and from the Zimbabwean Great Dyke. In this context, this article provides a comprehensive summary of detailed mining data between 2010 and 2015 and discusses these in regard...

Compression fracture of CFRP laminates containing stress intensifications

Christian Leopold, Martin Schütt, Wilfried Liebig, Timo Philipkowski, Jonas Kürten, Karl Schulte & Bodo Fiedler
For brittle fracture behaviour of carbon fibre reinforced plastics (CFRP) under compression, several approaches exist, which describe different mechanisms during failure, especially at stress intensifications. The failure process is not only initiated by the buckling fibres, but a shear driven fibre compressive failure beneficiaries or initiates the formation of fibres into a kink-band. Starting from this kink-band further damage can be detected, which leads to the final failure. The subject of this work is an...

Automatisierung der Weißlichtinterferometrie zur Inspektion rotationssymmetrischer Triebwerksbauteile

Tomas Domaschke
Die Arbeit umfasst die Entwicklung eines robotergestützten Systems zur Rissinspektion von Brennkammerbauteilen mittels Weißlichtinterferometrie. Aufgrund eines kleinen Sensormessbereichs und beschädigter Bauteile stellt die Inspektionsplanung eine Herausforderung dar. Der neuartige Lösungsansatz sieht ein zweistufiges Konzept vor. Dieses besteht aus einer modellbasierten Pfadplanung, bei der die Rotationssymmetrie des Bauteils genutzt wird und einer anschließenden Pfadadaption.

Dynamische Messung von Adsorptionsgleichgewichten an Nanopartikeln in nah- und überkritischen Lösungen: Experimenteller Ansatz und thermodynamische Modellierung

Johannes Kern
Die vorliegende Dissertation beschäftigt sich mit der experimentellen und theoretischen Darstellung der Adsorption gelöster Substanzen in überkritischem Kohlenstoffdioxid an Nanopartikel. Es wird zunächst die experimentelle Bestimmung von Adsorptionsgleichgewichten aus überkritischem Kohlenstoffdioxid an Nanopartikel behandelt. Dafür wurden Nanopartikel aus Al2O3 sowie AlO(OH) mit unterschiedlichen Packmethoden in chromatographische Säulen gepackt und die gepackten Säulen hinsichtlich Packungsqualität und Eignung für dynamische Adsorptionsmessmethoden charakterisiert. Dabei stellte sich heraus, dass ein Kompromiss zwischen Packungsqualität und Druckverlust der Säule eingegangen werden...

Investigation of core structure and stability of human Pyruvate Dehydrogenase complex: A coarse-grained approach

Samira Hezaveh, An-Ping Zeng & Uwe Jandt
The human pyruvate dehydrogenase complex (hPDC) is a large macromolecular machine, and its unique structural and functional properties make it a versatile target for manipulation aiming for the design of new types of artificial multienzyme cascades. However, model-based and hence systematic understanding of the structure−function relationship of this kind of complexes is yet poor. However, with new structure data, modeling techniques, and increasing computation power available, this shortfall is about to cease. Recently, we have...

Improving sustainability through digitalisation in reverse logistics

Sharon Cullinane, Michael Browne, Elisabeth Karlsson & Yingli Wang
Online purchases of clothes are increasing rapidly and with it, the number of returns. Return rates of clothing bought online can be up to 70%, involving high reverse logistics costs to retailers as well as sustainability costs to society. This paper seeks to illustrate how digitalisation can potentially decrease both such costs. The paper is based on a literature review and subsequent empirical research. Qualitative information was obtained through detailed interviews with key personnel and...

Substrates and oxygen dependent citric acid production by Yarrowia lipolytica: insights through transcriptome and fluxome analyses

Wael Sabra, Rajesh Reddy Bommareddy, Garima Maheshwari, Seraphim Papanikolaou & An-Ping Zeng
Unlike the well-studied backer yeast where catabolite repression represents a burden for mixed substrate fermentation, Yarrowia lipolytica, an oleaginous yeast, is recognized for its potential to produce single cell oils and citric acid from different feedstocks. These versatilities of Y. lipolytica with regards to substrate utilization make it an attractive host for biorefinery application. However, to develop a commercial process for the production of citric acid by Y. lipolytica, it is necessary to better understand...

Engineering 'cell robots' for parallel and highly sensitive screening of biomolecules under in vivo conditions

Lifu Song & An-Ping Zeng
Cells are capable of rapid replication and performing tasks adaptively and ultra-sensitively and can be considered as cheap "biological-robots". Here we propose to engineer cells for screening biomolecules in parallel and with high sensitivity. Specifically, we place the biomolecule variants (library) on the bacterial phage M13. We then design cells to screen the library based on cell-phage interactions mediated by a specific intracellular signal change caused by the biomolecule of interest. For proof of concept,...

RUVIVAL Publication Series Volume 2

Ahmad Al Baff, Alejandro Gonzalez Alvarez, Sing Yee Ho, Lukas Huhn, Rahel Birhanu Kassaye, Claudia Lasprilla Pina, Berenice Lopez Mendez, Valerie Mehl, Julia Möller & Ayodeji Oloruntoba
The bimonthly published RUVIVAL Publication Series is part of the e-learning project RUVIVAL. All topics of RUVIVAL Volume 2 are related and part of restoration engineering. Each contribution in this publication is connected to further interactive multimedia material, which can be reached under www.ruvival.de. This volume consists of 3 literature review papers. The first reviews aquifer recharge, a hydrologic process in which water moves from surface water to groundwater. The recharge of an aquifer can...

Eine Methode zur Bewertung von Anlaufrisiken in der Produktentwicklung für die Flugzeugindustrie

Steffen Elstner
In this thesis a methodical support for early identification and minimization of ramp-up risks with the help of response strategies is developed. Therefore the approach is divided into two main phases and focusing on the support of the product development until the transition to production. Within the first phase the identification of potential risk areas will be conducted based on a new impact model. During the second main phase the identified areas will be analyzed...

„How we bec[o]me metadata“ : Beschreiben, Finden, Weitergeben und Verändern von Open Educational Resources (OER)

Thomas Hapke
Metadaten beeinflussen die Qualität des Findens und Nutzens von Open Educational Resources (OER). Aufgrund der Vielfalt der medialen Formate und inhaltlichen Komponenten von OER mit ihrer spezifischen Granularität und ihren Möglichkeiten zum Weiternutzen und Verändern steht die Integration von Metadaten in Informations-Infrastrukturen für OER vor spezifischen Herausforderungen. OER-Metadaten enthalten optimalerweise neben allgemeinen, beschreibenden Elementen auch Daten zu technischen, pädagogischen und rechtlichen Randbedingungen der Nutzung. Gleichzeitig muss die Praktikabilität der Metadaten-Erfassung und -Weitergabe berücksichtigt werden, um...

An adaptive supply chain cyber risk management methodology

Stefan Schauer, Martin Stamer, Claudia Bosse, Michalis Pavlidis, Haralambos Mouratidis, Sandra König & Spyros Papastergiou
Maritime information infrastructures have developed to highly interrelated cyber ecosystems, where ports as well as their partners are connected in dynamic Information and Communication Technology (ICT)-based maritime supply chains. This makes them open and vulnerable to the rapidly changing ICT threat landscape. Hence, attacks on a seemingly isolated system of one business partner may propagate through the whole supply chain, causing cascading effects and resulting in large-scale impacts. In this article, we want to present...

Life cycle assessment for frozen food distribution schemes

Markus Trapp, Michael Lütjen, Juan Daniel Arango Castellanos, Oliver Jelsch & Michael Freitag
The online grocery market is facing big challenges. In addition to products for daily use, it is necessary to deliver fresh, chilled and frozen foods quickly and reliably to the customer. For decades frozen products have been delivered to the customers by using small cooling vans. Since some years, also normal parcel delivery services in combination with insulated shipping containers have been used. This article examines in a comparative analysis the environmental impact based on...

Literature classification on dispatching of container terminal vehicles

Anne Schwientek, Ann-Kathrin Lange & Carlos Jahn
Horizontal transport on container terminals represents the interface between quay and yard. Efficient transport operations are essential to improve performance and productivity. Thereby, one main decision problem is dispatching the vehicles. Despite the large amount of literature in this field, there is no classification or survey of the respective literature. Based on an extensive survey of dispatching literature published between 2000 and 2016, a classification scheme is developed and applied to 81 scientific publications. The...

Literature review of drivers of sustainable supply chain management

Muhammad Amad Saeed, Ishfaque Waseek & Wolfgang Kersten
The incremental awareness regarding social and environmental issues has pushed organizations to adopt sustainable practices. Over the last few years, organizations are considered to be responsible for their business activities that affect the environment, society, and the economy of their own business as well as their supply chain participants. Different stakeholders pressurize organizations and their supply chains to follow sustainable actions in order to achieve sustainable supply chain management (SSCM) goals. However, not all stakeholders...

Topical map for continuing education: AHP expert survey

Thomas Neukirchen & Matthias Klumpp
This contribution presents an analysis of recent trend topics in logistics and supply chain management with a focus on education and training on the job, applying an Analytic Hierarchy Process (AHP).Based on a comprehensive literature survey for the identification of trends that have persisted over the ten years considered (2005-2015), expert interviews have been conducted, aggregated and evaluated with an AHP. The particular context for this contribution is the research project MARTINA, which is concerned...

Assessing and improving countries’ logistics skills and training

Alan C. McKinnon, Kai Hoberg, Moritz Petersen & Christina Busch
Evidence is mounting to suggest that there is a global shortage of people with the right skills to meet the evolving needs of the logistics industry. Especially emerging regions are lagging behind, inhibiting economic growth. Thus, governments should systematically assess and address skills shortages in logistics. Commissioned by the World Bank, we devised a toolkit for assessing the availability of logistics skills within low- and middle-income countries. We built on the maturity model concept and...

Utility evaluation of battery electric vehicles in urban distribution

Dustin Schöder
Utilizing battery electric vehicles in daily distribution operations of logistics service providers and freight forwarders goes along with major uncertainties for companies. There is no mechanism how to evaluate the technical and economical use of battery electric vehicles in companies use cases and processes in status quo in contrast to vehicles with an internal engine. This paper adopts an evaluation mechanism from literature, which is bases on a value benefit analysis with compensation factors, and...

Reducing truck congestion at ports – classification and trends

Ann-Kathrin Lange, Anne Schwientek & Carlos Jahn
Truck drayage in container ports faces several challenges. Due to the ongoing growth of container ship sizes, there are increasingly high peak situations in landside container handling at logistic nodes in the port, e.g. container terminals, empty depots, freight stations. In combination with rising demands to improve the port’s ecological footprint this requires the port and its companies to adapt to the situation in order to reduce congestion. To identify important methods, key parameters, past...

Digitalization of logistics processes and the human perspective

Adina Silvia Kuhlmann & Matthias Klumpp
This contribution presents an analysis of the increasing consequences of digitalization with a focus on self-monitoring of personnel in logistics and production processes. This is of interest as digitalization requires large-scale innovative implementation and change management approaches in logistics and production processes. Based on standard DIN ISO 10.075 (’risk assessment’) an applicationoriented instrument is developed to evaluate und test new job systems, which are impacted by digitalization. This enables the development of digitalization strategies and...

Resource Types

  • Text
    134
  • Interactive resource
    1

Publication Year

  • 2017
    135

Registration Year

  • 2018
    7
  • 2017
    128