3,024 Works

Modeling and simulation of the start-up process of coal fired power plants with post-combustion CO₂ capture

Thomas Marx-Schubach & Gerhard Schmitz
A detailed model of a post-combustion CO₂ capture plant (pcc-plant) is developed in the Modelica ® language which allows the simulation of start-up and shutdown processes. The model of the pcc-plant is coupled to a simplified model of a coal fired power plant to investigate the coupled process. To guarantee a stable and automatic operation, a sequential control for start-up and shutdown procedures is implemented in both plants. Two case studies, focussing on the pcc-plant,...

Discovery of intramolecular signal transduction network based on a new protein dynamics model of energy dissipation

Cheng-Wei Ma, Zhi-Long Xiu & An-Ping Zeng
A novel approach to reveal intramolecular signal transduction network is proposed in this work. To this end, a new algorithm of network construction is developed, which is based on a new protein dynamics model of energy dissipation. A key feature of this approach is that direction information is specified after inferring protein residue-residue interaction network involved in the process of signal transduction. This enables fundamental analysis of the regulation hierarchy and identification of regulation hubs...

Stress-charge coupling coefficient for thin-film polypyrrole actuators – Investigation of capacitive ion exchange in the oxidized state

Benedikt Roschning & Jörg Weissmüller
This work quantifies the actuation behavior of thin electrodeposited polypyrrole films on rigid substrates. During in situ cantilever bending experiments in aqueous perchloric acid, the films remain clamped to their substrate and the film stress is inferred from a small bending of the cantilever. The potential range under study is 0.4–0.8 V versus the standard hydrogen electrode. Within this potential region, the film is in the oxidized state and the actuation arises from capacitive electrode...

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...

The effect of random wind forcing in the nonlinear Schrödinger equation

Leo Dostal
The influence of a strong and gusty wind field on ocean waves is investigated. How the random wind affects solitary waves is analyzed in order to obtain insights about wave generation by randomly time varying wind forcing. Using the Euler equations of fluid dynamics and the method of multiple scales, a random nonlinear Schrödinger equation and a random modified nonlinear Schrödinger equation are obtained for randomly wind forced nonlinear deep water waves. Miles theory is...

Thermodynamic assessment of the fixed-bed downdraft gasification process of fallen leaves pelletized with glycerol as binder

William A. González, Felix Zimmermann & Juan Fernando Pérez
In this work, the effect of airflow rate and glycerol content of pelletized fallen leaves (FL) on a fixed bed gasification process is studied. FLs were collected in the main campus of the University of Antioquia (Medellin, Colombia). Levels of airflow rate tested were 0.075, 0.150, and 0.225 kg/s/m2; and the glycerol content of pellets evaluated were 0 and 5%wt. When the airflow rate increased, flame front velocity increased up to 51.3%. This behavior was...

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...

Analysis of wind turbine using QBlade software

Mustafa Alaskari, Oday Ibraheem Abdullah & Mahir H. Majeed
Owing to the fast development in the energy field, the demands are increasing to improve energy efficiency and lifetime of wind turbine. The wind blades are considered as the most important and expensive part in the wind system. Therefore, it's important to understand deeply the behaviour of turbine blades. In this research paper, full details were presented to analyze and optimize the behaviour and performance of the blade of the small horizontal axis wind turbine...

An algorithm of daubechies wavelet transform in the final field when processing speech signals

Dmitry Popov, Artem Gapochkin & Alexey Nekrasov
Development and improvement of a mathematical model for a large-scale analysis based on the Daubechies discrete wavelet transform will be implemented in an algebraic system possessing a property of ring and field suitable for speech signals processing. Modular codes are widely used in many areas of modern information technologies. The use of these non-positional codes can provide high-speed data processing. Therefore, these algebraic systems should be used in the algorithms of digital processing of signals,...

Antimony mining from PET bottles and e-waste plastic fractions

Ayah Alassali, Caterina Picuno, Hanin Samara, Sascha Diedler, Silvia Fiore & Kerstin Kuchta
In this study antimony concentration was analyzed in 30 plastic items (from polyethylene terephthalate (PET) bottles and e-waste) directly by X-ray fluorescence spectroscopy (XRF) spectroscopy. PET samples were digested in a microwave oven with aqua regia. The plastic components deriving from e-waste followed three parallel routes: 1. microwave digestion using different acids (aqua regia, 18 M H2SO4, 12 M HCl and 6 M HCl); 2. conversion into ash (at 600 °C) and then microwave digestion...

Agrochemical plastic packaging waste decontamination for recycling: pilot tests in Italy

Caterina Picuno, Zoe Godosi, Kerstin Kuchta & Pietro Picuno
Agriculture, one of the main economic pillars in Europe, plays a growing important role towards the environmental sustainability of the extra-urban land, in which the agricultural activities may proactively contribute to control and regulate the whole ecological conditions. Modern agriculture currently needs big quantities of agrochemicals, which are necessary for the growth and protection of crops and animals. These agrochemicals are commercially distributed to consumers in many types of containers. The most widely used packaging...

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...

RUVIVAL Publication Series Volume 5

Zhuoheng Chen, Rahel Birhanu Kassaye, Ruth Schaldach, Antonio Seoane Dominguez, Tavseef Mairaj Shah & Sumbal Tasawwar
The RUVIVAL Publication Series is a compilation of literature reviews or introductory texts on topics concerned with the revitalisation of rural areas. It is part of the e-learning project RUVIVAL and each of the three contributions in this publication is connected to further interactive multimedia material, which can be reached under http://www.hoou.de. The first paper is an introduction to the global soil status, which in the past decades has continued to deteriorate. Globally, the total...

A consequential assessment of changes in greenhouse gas emissions due to the introduction of wheat straw ethanol in the context of European legislation

Benedikt Buchspies & Martin Kaltschmitt
Until today, first generation (1G) biofuels dominate the market for alternative fuels. The European Commission decided to cap 1G biofuels and promote second generation (2G) biofuels with the intention to reduce greenhouse gas (GHG) emissions, to limit the competition of food, feed and biofuels, as well as to improve societal approval. The assessment of consequences entailed to a shift from 1G to 2G biofuels is required to judge whether such a shift is advisable or...

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...

Low-pressure micro-mechanical re-adaptation device sustainably and effectively improves locomotor recovery from complete spinal cord injury

Veronica Estrada, Julia Krebbers, Christian Voss, Nicole Brazda, Heinrich Blazyca, Jennifer Illgen, Klaus Seide, Christian Jürgens, Jörg Müller, Rudolf Martini, Hoc Khiem Trieu & Hans Werner Müller
Traumatic spinal cord injuries result in impairment or even complete loss of motor, sensory and autonomic functions. Recovery after complete spinal cord injury is very limited even in animal models receiving elaborate combinatorial treatments. Recently, we described an implantable microsystem (microconnector) for low-pressure re-adaption of severed spinal stumps in rat. Here we investigate the long-term structural and functional outcome following microconnector implantation after complete spinal cord transection. Re-adaptation of spinal stumps supports formation of a...

Mass production of highly active NK cells for cancer immunotherapy in a GMP conform perfusion bioreactor

Katharina Bröker, Evgeny Sinelnikov, Dirk Gustavus, Udo Schumacher, Ralf Pörtner, Hans Hoffmeister, Stefan Lüth & Werner Dammermann
NK cells have emerged as promising candidates for cancer immunotherapy, especially due to their ability to fight circulating tumor cells thereby preventing metastases formation. Hence several studies have been performed to generate and expand highly cytotoxic NK cells ex vivo, e.g., by using specific cytokines to upregulate both their proliferation and surface expression of distinct activating receptors. Apart from an enhanced activity, application of NK cells as immunotherapeutic agent further requires sufficient cell numbers and...

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...

Iron oxide-based nanostructured ceramics with tailored magnetic and mechanical properties: Development of mechanically robust, bulk superparamagnetic materials

Diletta Giuntini, Elisa Torresani, Kyle T. Chan, Malte Blankenburg, Lucien Saviot, Büsra Bor, Berta Domènech Garcia, Meir Shachar, Martin Müller, Eugene A. Olevsky, Javier E. Garay & Gerold A. Schneider
Nanostructured iron-oxide based materials with tailored mechanical and magnetic behavior are produced in bulk form. By applying ultra-fast heating routines via spark plasma sintering (SPS) to supercrystalline pellets, materials with an enhanced combination of elastic modulus, hardness and saturation magnetization are achieved. Supercrystallinity-namely the arrangement of the constituent nanoparticles into periodic structures-is achieved through self-assembly of the organically-functionalized iron oxide nanoparticles. The optimization of the following SPS regime allows the control of organics' removal, necking,...

Comparative analysis and biochemical characterization of two endo-β-1,3-glucanases from the thermophilic bacterium fervidobacterium sp.

Christin Burkhardt, Christian Schäfers, Jörg Claren, Georg Schirrmacher & Garabed Antranikian
Laminarinases exhibit potential in a wide range of industrial applications including the production of biofuels and pharmaceuticals. In this study, we present the genetic and biochemical characteristics of FLamA and FLamB, two laminarinases derived from a metagenomic sample from a hot spring in the Azores. Sequence comparison revealed that both genes had high similarities to genes from Fervidobacterium nodosum Rt17-B1. The two proteins showed sequence similarities of 62% to each other and belong to the...

Aufgabenkonzepte für eine bessere Qualität von E-Prüfungen

Dennis Gallaun, Karsten Kruse & Christian Seifert
E-Assessment kann den Prüfungs- und Korrekturaufwand für die Lehrenden drastisch reduzieren. Es sollte aber auch dazu genutzt werden didaktisch anspruchsvolle Aufga-ben zu entwickeln. Im Rahmen von verschiedenen elektronischen Prüfungen in der Mathematik an der Technischen Universität Hamburg schreiben wir adaptive elektroni-sche Aufgaben mit automatischer Korrektur, und auf diesem Poster werden wir Aufga-benkonzepte vorstellen, mit denen sich die Qualität von Prüfungen verbessern lässt. Um insbesondere in großen Gruppen den Trainingsprozess für jede Studierende indivi-duell fair zu...

Mobiles Testcenter für E-Prüfungen

Dennis Gallaun, Karsten Kruse & Christian Seifert
Die Infrastruktur zur Durchführung von elektronischen Prüfungen ist meist stationärer Natur, d.h. sie werden in eigens dafür eingerichteten Räumen auf stationären Geräten durchgeführt. Das Hamburger MINTFIT Projekt [1] beschreitet hier einen anderen Weg und weicht vom Konzept eines stationären Testcenters ab, hin zu einem mobilen. Beim Hamburger MINTFIT Projekt handelt es sich um ein Kooperationsprojekt im Bereich E-Assessment von vier Hamburger Hochschulen und einem Universitätsklinikum, das neben der Erstellung von elektronischen Einstufungstests für das Studium...

Predicting industrial-scale cell culture seed trains – a bayesian framework for model fitting and parameter estimation, dealing with uncertainty in measurements and model parameters, applied to a nonlinear kinetic cell culture model, using an MCMC method

Tanja Hernández Rodríguez, Christoph Posch, Julia Schmutzhard, Josef Stettner, Claus Weihs, Ralf Pörtner & Björn Frahm
Biotechnology and Bioengineering Published by Wiley Periodicals, Inc. For production of biopharmaceuticals in suspension cell culture, seed trains are required to increase cell number from cell thawing up to production scale. Because cultivation conditions during the seed train have a significant impact on cell performance in production scale, seed train design, monitoring, and development of optimization strategies is important. This can be facilitated by model-assisted prediction methods, whereby the performance depends on the prediction accuracy,...

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,...

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