TY - JOUR A1 - Gebhardt, Andreas T1 - Generative Manufacturing of Ceramic Parts "Vision Rapid Prototyping" N2 - Table of Contents Introduction 1. Generative Manufacturing Processes 2. Classification of Generative Manufacturing Processes 3. Application of Generative Processes on the Fabrication of Ceramic Parts 3.1 Extrusion 3.2 3D-Printing 3.3 Sintering – Laser Sintering 3.4 Layer-Laminate Processes 3.5 Stereolithography (sometimes written: Stereo Lithography) 4. Layer Milling 5. Conclusion - Vision KW - Rapid prototyping KW - Rapid Technologie KW - Rapid Prototyping Y1 - 2006 ER - TY - JOUR A1 - Gebhardt, Andreas T1 - Rapid Manufacturing - eine interdisziplinäre Strategie N2 - Als um 1987 ein Verfahren namens Stereolithographie und ein Stereolithography Apparatus (SLA) vorgestellt wurden, war der Traum von der Herstellung beliebiger dreidimensionaler Bauteile direkt aus Computerdaten und ohne bauteilspezifische Werkzeuge Realität geworden. Ein Anwendungs-Szenario wurde gleich mitgeliefert. Diese Technologie würde es möglich machen, die gesamte Ersatzteilversorgung der Amerikanischen Pazifikflotte mittels ein paar dieser Maschinen, umfangreicher Datenstätze und genügend Rohmaterial vor Ort auf einem Flugzeugträger direkt nach Bedarf zu fertigen. Diese Vorstellung definierte schon damals die direkte digitale Fertigung, das Rapid Manufacturing. In der Realität bestanden die mit diesem Verfahren hergestellten Bauteile nur aus Kunststoff, waren ungenau, bruchempfindlich und klebrig und allein in der Produktentwicklung, eben als Prototypen zu benutzen. Sie waren schnell verfügbar, weil zu Ihrer Herstellung keine Werkzeuge benötigt wurden. Folgerichtige und zudem modern hießen sie: Rapid Prototyping. Rapid Prototyping wurde schnell zum Synonym eines neuen Zweiges der Fertigungstechnik, der Generativen Fertigungstechnik. Die weitere Entwicklung brachte neue Verfahren, höhere Genauigkeiten, verbesserte Werkstoffe und neue Anwendungen. Die Herstellung von Negativen, also Werkzeugen, mit dem gleichen Verfahren wurde marketing-getrieben Rapid Tooling genannt und als die ersten Bauteile nicht mehr als Prototypen, sondern als Endprodukte eingesetzt wurden, nannte man dies Rapid Manufacturing - das Ziel war erreicht. War das Ziel wirklich erreicht? Ist es Rapid Manufacturing, wenn ein generativ gefertigtes Bauteil die gewünschte Spezifikation erreicht? Was muss passieren, damit aus dem Phänomen Rapid Prototyping eine Strategie wird, die geeignet ist, einen Paradigmenwechsel von der heutigen Hersteller-induzierten Massenproduktion von Massenartikeln zur Verbraucher-induzierten (und verantworteten) Massenproduktion von Einzelteilen für jedermann ermöglichen und möglicherweise unsere Arbeits- und Lebensformen tiefgreifend zu beeinflussen? Im Beitrag wird der Begriff der (Fertigungs-) Strategie „Rapid Manufacturing“ näher beleuchtet. Es wird diskutiert, welche Maßnahmen auf der technischen und der operative Ebene getroffen werden müssen, damit die generative Fertigungstechnik im Sinne dieser Strategie umgesetzt werden kann. Beispiele belegen, dass diese Entwicklung bereits begonnen hat und geben Anregungen für eine konstruktive Diskussion auf der RapidTech 2006. N2 - As a process called stereolithography and a stereolithography apparatus (SLA) was presented in 1987, the dream of manufacturing any three-dimensional component directly from computer data and without component-specific tools became reality. An application scenario was supplied at the same time. This technology would make it possible to produce the entire spare parts requirement of the American Pacific Fleet merely through the use of a couple of such machines, extensive datasets and enough raw material on board an aircraft carrier directly as required. This image defined direct digital fabrication, rapid manufacturing, even at that time. In reality, this procedure only managed to produce components in plastic which were imprecise, fragile and sticky and only usable as prototypes in product development. They were rapidly available, because no tools were required for their manufacture. Consequentially, they are now known as Rapid Prototyping in modern jargon. Rapid Prototyping quickly became a synonym for a new branch of production engineering known as generative production engineering. Continued development brought new processes, improved accuracy, improved materials and new applications. The manufacturing of negatives, in other words tools, using the same procedure was quickly named rapid tooling by the marketing sector, and once the first components were used as final products instead of just prototypes the process was renamed "rapid manufacturing" - the goal had been reached. Was the goal really reached? Is it rapid manufacturing if a generatively manufactured component reaches the required specifications? What has to happen so that the rapid prototyping phenomenon becomes a strategy which is suitable for enabling the paradigm change from current manufacture-induced mass production of mass articles to consumer-induced (and consumer-responsible) mass production of single parts for anyone, and in all possibility makes dramatic changes in our way of working and living? The lecture includes detailed information about the (production) strategy term "rapid manufacturing". We will be discussing which measures need to be taken on the technical and operative level so that generative production engineering can be implemented in the sense of this strategy. Examples will show that this development has already started, and should provoke stimulation leading to constructive discussion during RapidTech 2006. KW - Rapid prototyping KW - Rapid Manufacturing KW - Rapid Prototyping KW - Stereolithographie KW - Generative Fertigungstechnik KW - Rapid prototyping KW - rapid manufacturing Y1 - 2006 ER - TY - CHAP A1 - Förster, Arnold A1 - Stock, Jürgen A1 - Montanari, Simone A1 - Lepsa, Mihail Ion A1 - Lüth, Hans T1 - Fabrication and characterisation of GaAs Gunn Diode Chips for applications at 77 GHz in automotive industry N2 - GaAs-based Gunn diodes with graded AlGaAs hot electron injector heterostructures have been developed under the special needs in automotive applications. The fabrication of the Gunn diode chips was based on total substrate removal and processing of integrated Au heat sinks. Especially, the thermal and RF behavior of the diodes have been analyzed by DC, impedance and S-parameter measurements. The electrical investigations have revealed the functionality of the hot electron injector. An optimized layer structure could fulfill the requirements in adaptive cruise control (ACC) systems at 77 GHz with typical output power between 50 and 90 mW. KW - Biosensor KW - Gunn diode KW - microwave generation KW - GaAs hot electron injector Y1 - 2006 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:a96-opus-1462 ER - TY - CHAP A1 - Fredebeul-Krein, Markus T1 - Developing competitive broadband markets: Lessons learnt from German and European regulatory approaches on broad-band access N2 - A key feature of future broadband markets will be diversity of access technologies, meaning that numerous technologies will be exploited for broadband communication. Various factors will affect the success of these future broadband markets, the regulatory policy being one amongst others. So far, a coherent regulatory approach does not exist as to broadband markets. First results of policies so far suggest that less sector-specific regulation is likely to occur. Instead, regulators must ensure that access to networks and services of potentially dominant providers in a relevant broadband market will satisfy requirements for openness and non-discrimination. In this environment the future challenge of regulationg broadband markets will be to set the right incentives for investment into new infrastructures. This paper examines whether there is a need for the regulation of future broadband access markets an if yes, what is the appropriate regulatory tool to do so. Thereby the focus is on the analysis of European broadband markets and the regulatory approaches applied. The first section provides a description of the characteristics of future broadband markets. The second section discusses possible bottlenecks on broadband markets an their regulatory implications. The third section will examine regulatory issues concerning access to broadband networks in more detail. This will be done by comparing the regulatory approaches of European countries and the results in terms of bradband penetration. The final section will give key recommendations for a regulatory strategy on brandband access markets. KW - Telekommunikationsmarkt KW - Telekommunikationsmarkt Y1 - 2006 N1 - paper presented at 16th Biennial conference of the International Telecommunications Society. Information Communication Technology: Opportunities and Challenges for Telecommunications. June 12-16, 2006 Beijing, China. ER - TY - CHAP A1 - Chaiyboun, Ali A1 - Traute, Rüdiger A1 - Kiesewetter, Olaf A1 - Ahlers, Simon A1 - Müller, Gerhard A1 - Doll, Theodor T1 - Modular analytical multicomponent analysis in gas sensor arrays N2 - A multi-sensor system is a chemical sensor system which quantitatively and qualitatively records gases with a combination of cross-sensitive gas sensor arrays and pattern recognition software. This paper addresses the issue of data analysis for identification of gases in a gas sensor array. We introduce a software tool for gas sensor array configuration and simulation. It concerns thereby about a modular software package for the acquisition of data of different sensors. A signal evaluation algorithm referred to as matrix method was used specifically for the software tool. This matrix method computes the gas concentrations from the signals of a sensor array. The software tool was used for the simulation of an array of five sensors to determine gas concentration of CH4, NH3, H2, CO and C2H5OH. The results of the present simulated sensor array indicate that the software tool is capable of the following: (a) identify a gas independently of its concentration; (b) estimate the concentration of the gas, even if the system was not previously exposed to this concentration; (c) tell when a gas concentration exceeds a certain value. A gas sensor data base was build for the configuration of the software. With the data base one can create, generate and manage scenarios and source files for the simulation. With the gas sensor data base and the simulation software an on-line Web-based version was developed, with which the user can configure and simulate sensor arrays on-line. KW - Biosensor KW - Main sensitivity KW - cross sensitivity KW - matrix method KW - gas sensor array KW - modelling Y1 - 2006 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:a96-opus-1358 ER - TY - CHAP A1 - Bührig-Polaczek, Andreas A1 - Röth, Thilo A1 - Baumeister, E. A1 - Nowack, N. A1 - Süßmann, Torsten T1 - Hybride Leichtbaustrukturen in Stahlblech-Leichtmetall Verbundguss N2 - Stahl-Leichtmetall-Hybride mit hohen Leistungspotentialen können heute wirtschaftlich abgebildet werden und eignen sich möglicherweise auch zum Einsatz in Fahrzeugkarosserien KW - Karosseriebau KW - Verbundguss KW - Stahlblech-Leichtmetall Verbundguss KW - Stahlblech-Leichtmetall-Hybride KW - Lightweight car body construction Y1 - 2006 ER - TY - CHAP A1 - Bukhari, Syed Faisal Ahmed A1 - Yang, Wuqiang T1 - Multi-interface level sensors and new development in monitoring and control of oil separators N2 - In the oil industry, huge saving may be made if suitable multi-interface level measurement systems are employed for effectively monitoring crude oil separators and efficient control of their operation. A number of techniques, e.g. externally mounted displacers, differential pressure transmitters and capacitance rod devices, have been developed to measure the separation process with gas, oil, water and other components. Because of the unavailability of suitable multi-interface level measurement systems, oil separators are currently operated by the trial-and-error approach. In this paper some conventional techniques, which have been used for level measurement in industry, and new development are discussed. KW - Biosensor KW - Level sensor KW - multi-interface measurement KW - electrical capacitance tomography KW - ECT Y1 - 2006 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:a96-opus-1498 ER - TY - CHAP A1 - Bornebusch, Michael T1 - Hydraulische und hydrologische Modellsimulation als Planungswerkzeug für Hochwasser-Schutz-Massnahmen N2 - In: Alfha.net / Sektion Bauingenieurwesen: 1. [Erster] Erfahrungsaustausch : Absolventen des Fachbereichs Bauingenieurwesens berichten. 13. Oktober 2006. S. 25-27. Zusammenfassung des Vortrags. KW - Hochwasserschutz KW - Niederschlag-Abfluss-Modelle KW - N-A-Modelle KW - Gewässerausbau Y1 - 2006 ER - TY - CHAP A1 - Becker, Astrid T1 - Anlagenmanagement und Aufgaben der DB Netz AG, Bauherrenvertretung und Wirtschaftlichkeit N2 - In: Alfha.net / Sektion Bauingenieurwesen: 1. [Erster] Erfahrungsaustausch : Absolventen des Fachbereichs Bauingenieurwesens berichten. 13. Oktober 2006. S. 18 Übersicht des Vortrags KW - Anlagenwirtschaft KW - Bauherrenvertretung KW - Deutsche Bahn Netz AG Y1 - 2006 ER - TY - CHAP A1 - Baronas, Romas A1 - Ivanauskas, Feliksas A1 - Kulys, Juozas T1 - Mathematical modeling of biosensors based on an array of enzyme microreactors N2 - This paper presents a two-dimensional-in-space mathematical model of biosensors based on an array of enzyme microreactors immobilised on a single electrode. The modeling system acts under amperometric conditions. The microreactors were modeled by particles and by strips. The model is based on the diffusion equations containing a nonlinear term related to the Michaelis-Menten kinetics of the enzymatic reaction. The model involves three regions: an array of enzyme microreactors where enzyme reaction as well as mass transport by diffusion takes place, a diffusion limiting region where only the diffusion takes place, and a convective region, where the analyte concentration is maintained constant. Using computer simulation, the influence of the geometry of the microreactors and of the diffusion region on the biosensor response was investigated. The digital simulation was carried out using the finite difference technique. KW - Biosensor KW - Reaction-diffusion KW - modeling biosensor KW - microreactor Y1 - 2006 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:a96-opus-1569 ER -