And Construction (and + construction)

Distribution by Scientific Domains
Distribution within Engineering

Kinds of And Construction

  • design and construction


  • Selected Abstracts


    Design and Construction of Insulation Configuration for Ultra-High-Temperature Microwave Processing of Ceramics

    JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 12 2003
    Geng-fu Xu
    A multilayer insulation configuration suitable for microwave sintering of ceramics up to 2100°C was designed and tested successfully. The configuration is based on porous, granular BN/ZrO2 fiber composite powder for packed beds and spacer cylinders. This insulation allows stable, controlled microwave sintering and can be modified to microwave process materials with different thermal, dielectric properties with improved properties. [source]


    Virtuelles Bauen und partnerschaftliche Geschäftsmodelle , eine innovative Verbindung

    BAUTECHNIK, Issue 7 2006
    Mike Gralla Univ.-Prof.
    Durch eine frühe Zusammenarbeit von Bauherrn, Planern und Bauunternehmen können mit partnerschaftlichen Geschäftsmodellen wesentliche Nachteile von herkömmlichen Geschäftsbeziehungen im Bauwesen aufgelöst werden. Die enge Zusammenarbeit in einer frühen Phase eines Bauvorhabens ermöglicht eine fachübergreifende Optimierung hinsichtlich Planung, Bauausführung und Nutzung einer Immobilie. Hierbei sind die Methoden des virtuellen Bauens zweckmäßige Hilfsmittel, um die Koordination des Projekts und die Kommunikation zwischen den an einem Bauvorhaben beteiligten Partnern zu verbessern. Deshalb hat sich insbesondere bei partnerschaftlichen Geschäftsmodellen, die eine Preconstruction-Phase enthalten, die Verwendung von virtuellem Bauen als besonders wirksam erwiesen. Virtuelles Bauen unterstützt die Optimierung eines Bauwerks und hilft bei der anschaulichen Kommunikation von Optimierungsergebnissen durch die Visualisierung mit interaktiven Computermodellen. Virtual Design and Construction (ViCon) führt das virtuelle Bauen in die tägliche Planungs- und Baupraxis ein und ist eine Schlüsseltechnologie des Bauwesens. ViCon wird in der Praxis bei zahlreichen Projekten eingesetzt, die mit dem partnerschaftlichen Geschäftsmodell PreFair durchgeführt werden. In diesem Beitrag werden die Einsatzmöglichkeiten von ViCon an ausgewählten Beispielen dargestellt. Virtual construction and partnership-based business models , an innovative combination. When clients, design engineers and construction companies work together within the framework of partnership-based business models from an early stage, major disadvantages of traditional business relationships in the construction sector can be eliminated. Close cooperation in an early phase of a construction project makes for interdisciplinary optimization with regard to a property's design, construction and utilization. In this context, the methods of virtual construction are useful tools to improve communication between the parties involved in a construction project. Using virtual construction has therefore proved to be particularly effective when working with partnership-based business models that comprise a preconstruction phase. Virtual construction helps to optimize building structures and assists in graphically communicating optimization results by way of visualization with interactive computer models. Virtual Design and Construction (ViCon) introduces virtual construction in the daily design and construction work and is a key technology in the construction industry. In practice, ViCon is employed in numerous projects that are implemented based on the PreFair business model. Using selected examples, this article shows the range of ViCon's possible application. [source]


    Spatial Information: Classification and Applications in Building Design

    COMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 4 2002
    Tang-Hung Nguyen
    Physical properties of building components are usually represented in building data models by their three-dimensional geometry and topology,also called spatial information. While geometric data of building components can be manipulated and managed by a computer-aided design (CAD) interface, their spatial relations (or topological information) are conventionally represented in a manual fashion into data models. The manual data representation, however, is inherently a complex and challenging task due to the wide variety of spatial relationships. Thus, topological information should be classified and modeled in such a way that the required spatial data for a particular design task can be automatically retrieved. This paper attempts to identify and classify various topological information commonly used in building design and construction into more specific categories (e.g., adjacency, connection, containment, separation, and intersection) to support automatic deduction of the spatial information in a computer-based building design system. The paper also discusses typical applications of the topological relations to different design activities. Finally, the development of deduction algorithms and the proposed building design system are briefly described. [source]


    Designing new institutions for implementing integrated disaster risk management: key elements and future directions

    DISASTERS, Issue 4 2007
    Chennat Gopalakrishnan
    The goal of integrated disaster risk management is to promote an overall improvement in the quality of safety and security in a region, city or community at disaster risk. This paper presents the case for a thorough overhaul of the institutional component of integrated disaster risk management. A review of disaster management institutions in the United States indicates significant weaknesses in their ability to contribute effectively to the implementation of integrated disaster risk management. Our analysis and findings identify eight key elements for the design of dynamic new disaster management institutions. Six specific approaches are suggested for incorporating the identified key elements in building new institutions that would have significant potential for enhancing the effective implementation of integrated disaster risk management. We have developed a possible blueprint for effective design and construction of efficient, sustainable and functional disaster management institutions. [source]


    Geothermal energy systems for major projects , design and construction / . Geothermieanlagen bei Großprojekten , Planung und Umsetzung

    GEOMECHANICS AND TUNNELLING, Issue 5 2010
    Dipl.-Ing.
    Geothermal energy - Geothermie Abstract The application of geothermal energy has increased in the last couple of years in order to provide the heating or cooling demands of major projects. Open systems using groundwater directly can be used for geothermal energy extraction as well as closed systems with absorber pipes installed in underground structures. An accurate design, which considers the requirements of the energy consumer in particular but also the subsoiland groundwater conditions, the foundation concept and the building structure, as well as project-specific technical, legal and economic conditions, is required for economically efficient application. Diligent supervision is necessary during the construction stage to avoid any damage to absorber pipes, which could result in loss of performance. Zur Deckung des Heiz- oder Kühlbedarfs bei Großprojekten wird in den letzten Jahren vermehrt auf eine Erdwärmenutzung gesetzt. Dabei kommen sowohl offene Systeme wie eine direkte Grundwassernutzung als auch geschlossene Systeme mit Absorberleitungen in erdberührten Bauteilen zur Anwendung. Für eine wirtschaftliche Umsetzung bedarf es zunächst einer sorgfältigen Planung, wobei insbesondere die Anforderungen des Nutzers, die Untergrund- und Grundwasserverhältnisse, das Gründungskonzept einschließlich der Gebäudestruktur sowie projektspezifische technische, rechtliche und wirtschaftliche Randbedingungen zu berücksichtigen sind. In der Bauphase ist für eine plangemäße Umsetzung mit besonderer Sorgfalt vorzugehen, um Beschädigungen der Absorberleitungen und somit Leistungsminderungen zu vermeiden. [source]


    Geomechanics and Tunnelling 2/2010

    GEOMECHANICS AND TUNNELLING, Issue 1 2010
    Article first published online: 24 FEB 2010
    Semmering and Koralm tunnels Neue Südbahn, Semmering und Koralm Tunnel F. Bauer: Investment in the Austrian rail network , overview of new and upgrading projects , Investitionen in das österreichische Schienennetz , Überblick Neu- und Ausbauvorhaben G. Gobiet and D. Haas: New Semmering Base Tunnel project , an interdisciplinary challenge , Semmering Basistunnel Neu , eine interdisziplinäre Herausforderung A. Fasching, R. Vanek, Th. Stadlmann, P. Reichl, G. Domberger, G. Forstinger and O. Wagner: New Semmering Base Tunnel , the investigation programme 2008/2009 and the knowledge gained in the areas of geology, hydrogeology and geotechnical engineering , Semmering-Basistunnel Neu , Das Erkundungsprogramm 2008/2009 und die daraus gewonnenen Erkenntnisse auf den Gebieten der Geologie, Hydrogeologie und Geotechnik J. Daller, A. Vigl and O. Wagner: New Semmering Base Tunnel , the current state of tunnel design taking the newest investigation results into account , Semmering-Basistunnel Neu , Aktueller Stand der Tunnelplanung unter Berücksichtigung der neuesten Erkundungsergebnisse R. Bopp, V. Langer, Ch. Neumann and O. Wagner: The ventilation and tunnel safety concept for the New Semmering Base Tunnel , Das Lüftungs- und Tunnelsicherheitskonzept für den Semmering-Basistunnel Neu G. Harer and J. Koinig: Current state of design, investigation and construction work at the Koralm Tunnel , Aktueller Stand der Planungs-, Erkundungs- und Ausführungsarbeiten beim Koralmtunnel P. Schubert, H. Hölzl, P. Sellner and F. Fasching: Geomechanical knowledge gained from the Paierdorf Investigation Tunnel in the section through the Lavanttal main fault zone , Geomechanischer Wissenszuwachs durch den Erkundungstunnel Paierdorf im Abschnitt der Lavanttaler Hauptstörungszone D. Handke, M. Nolden, K. Mussger and A. Steidl: Solution methods for the design and construction of contract KAT 3 , Lösungsansätze für Planung und Bauausführung des Bauloses KAT 3 M. Vill, H. Wagner, A. Schweighofer, H. Huber, W. Pichler and J. Kollegger: New development of a crack-limited invert slab , Neuentwicklung der rissebeschränkten Sohlplatte M. Stopka: Hengsberg Tunnel , the construction contract as seen by the contractor , Hengsbergtunnel , der Bauvertrag aus Sicht des Auftragnehmers T. Schachinger, H. Gaube and G. Krainer: Results from the Untersammelsdorf test field for the planning of the tunnelling work , Erkenntnisse aus dem Versuchsfeld Untersammelsdorf für die Gestaltung der Vortriebsmaßnahmen K. Chmelina and K. Rabensteiner: Improvement of the safety and profitability of tunnel drives through the use of automated measurement and alarm systems , examples in practice , Verbesserung der Sicherheit und Wirtschaftlichkeit von Tunnelvortrieben durch den Einsatz automatisierter Mess- und Alarm-systeme , Ausführungsbeispiele [source]


    A modular approach to addressing model design, scale, and parameter estimation issues in distributed hydrological modelling

    HYDROLOGICAL PROCESSES, Issue 2 2002
    G. H. Leavesley
    Abstract A modular approach to model design and construction provides a flexible framework in which to focus the multidisciplinary research and operational efforts needed to facilitate the development, selection, and application of the most robust distributed modelling methods. A variety of modular approaches have been developed, but with little consideration for compatibility among systems and concepts. Several systems are proprietary, limiting any user interaction. The US Geological Survey modular modelling system (MMS) is a modular modelling framework that uses an open source software approach to enable all members of the scientific community to address collaboratively the many complex issues associated with the design, development, and application of distributed hydrological and environmental models. Implementation of a common modular concept is not a trivial task. However, it brings the resources of a larger community to bear on the problems of distributed modelling, provides a framework in which to compare alternative modelling approaches objectively, and provides a means of sharing the latest modelling advances. The concepts and components of the MMS are described and an example application of the MMS, in a decision-support system context, is presented to demonstrate current system capabilities. Copyright © 2002 John Wiley & Sons, Ltd. [source]


    Geotechnical parameter estimation in tunnelling using relative convergence measurement

    INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 2 2006
    Kook-Hwan Cho
    Abstract Accurate estimation of geotechnical parameters is an important and difficult task in tunnel design and construction. Optimum evaluation of the geotechnical parameters have been carried out by the back-analysis method based on estimated absolute convergence data. In this study, a back-analysis technique using measured relative convergence in tunnelling is proposed. The extended Bayesian method (EBM), which combines the prior information with the field measurement data, is adopted and combined with the 3-dimensional finite element analysis to predict ground motion. By directly using the relative convergence as observation data in the EBM, we can exclude errors that arise in the estimation of absolute displacement from measured convergence, and can evaluate the geotechnical parameters with sufficient reliability. The proposed back-analysis technique is applied and validated by using the measured data from two tunnel sites in Korea. Copyright © 2005 John Wiley & Sons, Ltd. [source]


    Great EscApe: the great ape facility at Oklahoma City Zoological Park

    INTERNATIONAL ZOO YEARBOOK, Issue 1 2000
    J. GRISHAM
    On 31 July 1993, after nearly 4 years of design and construction, Oklahoma City Zoological Park opened Great EscApe, a state-of-the-art exhibit for the maintenance and conservation of three species of great ape: Western lowland gorilla Gorilla gorilla gorilla, Sumatran orang-utan Pongo pygmaeus abelii and Chimpanzee Pan troglodytes. The 2,6 ha enclosure comprises a large support facility, four spacious outdoor exhibit areas, two visitor centres, a children's activity loop, an open-air pavilion and a research station. In addition, Great EscApe provides an educational experience for visitors covering all facets of great ape biology and the conservation challenges which these species present. Extensive landscaping with plants, many of which simulate the natural surroundings of the apes, was utilized throughout the exhibit. [source]


    Nocturnal swimming, aggregation at light traps, and mass spawning of scissurellid gastropods (Mollusca: Vetigastropoda)

    INVERTEBRATE BIOLOGY, Issue 1 2007
    Carole S. Hickman
    Abstract. Thousands of minute scissurellid gastropods (Vetigastropoda: Scissurellidae) were observed and collected at floating light traps in Moorea, French Polynesia, where a mass spawning event occurred on November 11, 2002. More than 20,000 live snails were recovered from the traps, and epidemic spawning continued in the laboratory, where clouds of white sperm and red-orange eggs were broadcast into the water. No aggregations of this magnitude have been reported previously in vetigastropods, nor is the capacity for sustained swimming known from other vetigastropod taxa. Snails had emerged from a local benthic habitat of coral sand and swum through ,2 m of water to reach the traps. Scanning electron micrographs of the ornate shells confirm the identity of the most abundant species as Scissurella spinosa, with lesser numbers of Sinezona plicata. Our observations indicate that scissurellids are not exclusively benthic and that they are not rare, even though they have seldom been collected and studied alive. Because little is known about the basic biology and anatomy of scissurellids and because their position within the basal Gastropoda is poorly resolved, we include information on the design and construction of inexpensive light traps to promote comparative investigation of other poorly known species. [source]


    Separation of chiral mixtures in real SMB units: The FlexSMB-LSRE®

    AICHE JOURNAL, Issue 1 2010
    Pedro Sá Gomes
    Abstract In this work, a procedure for the separation of a racemic mixture of guaifenesin onto a chiral stationary phase (Chiralpak AD), by means of Simulated Moving Bed (SMB) technology, is presented in four major steps: (1) search for the suitable stationary and mobile phases; (2) determination of sorption parameters and validation by frontal analysis; (3) modeling and design of the SMB unit; and (4) operation and demonstration. A major emphasis is given to the common deviations that "real" SMB units present when compared with the theoretical apparatus (due to tubing and equipment dead volumes, switching time asymmetries and delays, pumps flow rates variations). These deviations are analyzed before and after the design and construction of the FlexSMB-LSRE® unit, a new flexible unit, hereby presented. A detailed model that takes into account tubing and equipment dead volumes, as well as switching time asymmetries and delay, was used to study and compare different dead volumes design and compensating strategies. It is shown that all these approaches can be converged into a switching time compensating strategy. This approach served to predict the experimental operating conditions and run a classical SMB experiment, which afterwards was compared with the simulated profiles obtained for the FlexSMB-LSRE® unit. The result of the separation was guaifenesin enantiomers with purities above 98% and a productivity value of 23 genantiomer/(dm3 CSP day). © 2009 American Institute of Chemical Engineers AIChE J, 2010 [source]


    Utilizing a library of synthetic affinity ligands for the enrichment, depletion and one-step purification of leech proteins

    JOURNAL OF MOLECULAR RECOGNITION, Issue 3 2008
    Dexian Dong
    Abstract Although the concept of affinity purification using synthetic ligands had been utilized for many years, there are few articles related to this research area, and they focus only on the affinity purification of specific protein by a defined library of synthetic ligands. This study presents the design and construction of a 700-member library of synthetic ligands in detail. We selected 297 ligand columns from a 700-member library of synthetic ligands to screen leech protein extract. Of the 297, 154 columns had an enrichment effect, 83 columns had a depletion effect, 36 columns had a one-step purification effect, and 58 columns had a one-step purification via flowthrough effect. The experimental results achieved by this large library of affinity ligands provide solid convincing data for the theory that affinity chromatography could be used for the enrichment of proteins that are present in low abundance, the depletion of high abundance proteins, and one-step purification of special proteins. Copyright © 2008 John Wiley & Sons, Ltd. [source]


    Maintenance issues in the Web site development process

    JOURNAL OF SOFTWARE MAINTENANCE AND EVOLUTION: RESEARCH AND PRACTICE, Issue 2 2002
    M. Taylor
    Abstract There appears to be few actual case studies in academic or professional literature regarding the overall process of developing a company Web site and even fewer regarding the maintenance of company Web sites. In this paper, we examine the maintenance issues in the Web site development process based on detailed case studies in seven U.K. organizations from the engineering, financial services, retail, manufacturing and education sectors over a two year period. This research indicated that there are numerous issues in Web site design and construction that impact upon future Web site maintenance activities. In particular, this research examined the impact of dynamic Web site data, Web site structure, specific coding for different user groups/Internet browsers/navigators/Internet search engines, Web site documentation and Web site development and testing standards upon future Web site maintenance work. Copyright © 2002 John Wiley & Sons, Ltd. [source]


    Experimental study of sealed off operation of a high repetition rate TEA CO2 laser

    LASER PHYSICS LETTERS, Issue 10 2006
    M. J. Torkamany
    Abstract Design and construction of a high repetition rate low average power TEA CO2 laser with ultra violet pre ionization is presented. Replacing thyratron with a high voltage semiconductor switch and magnetic pulse compressor considering the highest peak power achievable is investigated. When using semiconductors as main switch of laser excitation circuit the output energy and laser power is lower about 5,10% relative to thyratron excitation circuit but the sealed off operation of laser is more uniform. (© 2006 by Astro, Ltd. Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA) [source]


    Protection capabilities of nanostructured shells toward cell encapsulation: A saccharomyces/paramecium model

    MICROSCOPY RESEARCH AND TECHNIQUE, Issue 10 2010
    Raffaella Magrassi
    Abstract In this work we report the formation of nanostructured hybrid objects, made up of living cells encapsulated in a protective multilayer shell assembly of nanostructured polyelectrolyte. Such constructs can be hosted on nanostructured surfaces or can be installed around living organisms, at the right time. Their construction is based on the layer-by-layer (LbL) self-assembly of two oppositely alternated charged polyelectrolytes (PEs) on cell membranes as earlier done for nanocapsules or fuzzy structured nanoshells. This communication reports the optimal conditions for cell encapsulation in terms of nanoshell design and construction. Microsc. Res. Tech. 73:931,936, 2010. © 2010 Wiley-Liss, Inc. [source]


    Object-Oriented Performance Improvement

    PERFORMANCE IMPROVEMENT QUARTERLY, Issue 3 2002
    Ian Douglas
    ABSTRACT In this paper, a framework to support an object-oriented approach to performance analysis is described. The framework includes the use of collaboration, automation, visual modeling, and reusable repositories of analysis knowledge. The need for a new framework is related to the increasing concern with the cost effectiveness of student and employee development. Efforts to improve the return-on-investment in such development have been hindered by a craft orientation to the design and construction of learning and performance support materials. One solution to this problem has been to enhance the reuse of such materials. Rather than build every new system from scratch in a craft-oriented manner, it is envisioned that systems will be constructed largely of standardized, reusable objects shared through Web-based repositories. Currently, the main focus is on the technological framework necessary for an object-based approach to learning system development. There appears to be little consideration of the changes in analysis and design thinking required for the move towards object-based systems. Such systems should still be required to be directly linked to performance problems and opportunities at both the organizational and individual system levels. [source]


    Fast near-infra-red spectroscopic Mueller matrix ellipsometer based on ferroelectric liquid crystal retarders

    PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 5 2008
    J. Ladstein
    Abstract This paper reports on the design and construction of the first near-infra-red spectroscopic Mueller Matrix Ellipsometer (MME) based on Ferroelectric Liquid Crystal retarders (FLC) and fixed waveplates. The design was performed by assuming ideal optical polarizing components. In particular, the current FLC-MME is optimised to operate in the near-infra-red (NIR) spectral range from 800 nm to 1800 nm. The FLC based Polarization State Generator (PSG) and Polarization State Analyzer (PSA) have been optimized by keeping the condition number of the PSG's modulation matrix and the PSA's analysis matrix close to an optimum over the spectral design range. The design is realized in a setup using the full Mueller matrix measurement formalism based on the Eigenvalue Calibration Method (ECM). The actual modulation matrix and analysis matrix are obtained from the ECM, and the condition numbers immediately indicates the quality of the design. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


    Site characterization to support permeable reactive barrier design

    REMEDIATION, Issue 4 2005
    Lynn A. Morgan
    Careful design studies and selection of an effective technique for the installation of permeable reactive barriers (PRBs) are important contributors to the overall success of zero-valent iron PRBs. This article provides a case study summarizing the successful design and construction of a PRB installed at the former Carswell Air Force Base located in Fort Worth, Texas. Expedited site characterization using a cone penetrometer rig equipped with a mass spectrometer was employed to provide real-time characterization and lithologic data. These data proved to be invaluable for the design of the PRB and allowed for the development of an accurate preconstruction cost estimate. Field data gained from the expedited water quality and geologic characterization along with aquifer testing and a bench-scale treatability study provided a comprehensive basis for the design. The biopolymer slurry construction technique provided additional unanticipated benefits to the designed zero- valent iron treatment by promoting the development of anaerobic conditions favorable for microbial degradation of trichloroethene. Postconstruction monitoring data are discussed to illustrate the successful performance of the PRB. © 2005 Wiley Periodicals, Inc. [source]


    Magnetization of Ancient Ceramics

    ARCHAEOMETRY, Issue 1 2001
    J. Van Klinken
    The saturation magnetization , of soft baked pottery appears to be determined during the firing process by transitions between the iron oxides magnetite, maghemite, hematite and perhaps goethite. The finding of large variations in , motivated the design and construction of a ,magnetization,gravitation', or ,MG', balance for rapid non-destructive magnetization measurements. The first results with this MG balance are presented: iso-, contours, typical histograms and correlations with colour features. Practical MG applications are summarized. [source]


    Geometry and New and Future Spatial Patterns

    ARCHITECTURAL DESIGN, Issue 6 2009
    Helmut Pottman
    Abstract Despite architects' preoccupation with designing geometric surfaces, there has remained a gap between design and construction. The realisation of complex architectural freeform shapes and the generation of panel patterns continues to be especially challenging, limited by material and manufacturing constraints. Here, Helmut Pottmann, Head of Geometric Modelling and the Industrial Geometry Group within the Institute of Discrete Mathematics and Geometry at Vienna University of Technology (TU Vienna), explores the possibilities thrown up by new research employing fabrication-aware design software. Copyright © 2009 John Wiley & Sons, Ltd. [source]


    Video-rate scanning probe control challenges: setting the stage for a microscopy revolution

    ASIAN JOURNAL OF CONTROL, Issue 2 2009
    M. J. Rost
    Abstract Scanning probe microscopy is at the verge of revolutionizing microscopy once again. Video-rate scanning tunneling microscope (STM) and video-rate atomic force microscope (AFM) technology will enable the direct observation of many dynamic processes that are impossible to observe today, such as atom or molecule diffusion, real time film growth, or catalytic reactions. In this paper we discuss the critical aspects that have to be taken into account when working on increasing the imaging speed of scanning probe microscopes. We highlight the state-of-the-art developments in the control of the piezoelectric scanning elements and describe the latest innovations regarding the design and construction of the whole mechanical loop including new scanner geometries. We identify critical aspects for which no obvious solution exists and aspects where advanced control engineering can help, like piezo non-linearities, the acceleration limit and the challenging technical requirements for the preamplifiers that are needed for measuring a tunneling current. Finally, we provide an overview of a number of new directions that are being pursued to solve the problems currently encountered in scanning probe technology. Copyright © 2009 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society [source]


    Planung und Bauausführung des Al-Sadd Stadions in Doha, Katar

    BAUTECHNIK, Issue 6 2005
    Geschäftsführender Gesellschafter Richard Stroetmann Dr.-Ing.
    Das Stadion des Al-Sadd Sports Club, dem renommiertesten Fußballklub des Emirats Katar, wurde in einem Zeitraum von rund 14 Monaten renoviert und in großen Teil en durch einen Neubau ersetzt. Der Beitrag berichtet über Besonderheiten bei der Planung und Bauausführung dieses Projekts. Auf die Stabilitätsberechnung des bogenförmigen Dachtragwerks wird detailliert eingegangen. Design and construction of the Al-Sadd Stadium in Doha, Qatar. The stadium of Al-Sadd Sports Club, which is the most famous soccer club of the state of Qatar, has recently been upgraded and in large parts been reconstructed from scratch within a period of 14 months. The paper describes some specific features of the design and the construction of this project. The issue of lateral torsional buckling of the curved roof structure and the respective calculations are addressed in detail. [source]


    Die Abnahme von Tiefgaragen aus technischer Sicht

    BETON- UND STAHLBETONBAU, Issue 4 2006
    Klaus Schöppel Dr.-Ing.
    Die Praxis zeigt, daß in Tiefgaragen infolge mangelhafter Planung und Ausführung ein erhebliches Schadenspotential vorliegt. Die Schäden infolge dieser Mängel treten augenscheinlich erkennbar erst nach einigen Jahren , meist nach Ablauf der Gewährleistung , auf. Daher ist eine sorgfältige Kontrolle bei der Abnahme von Tiefgaragen notwendig, um derartige Mängel frühzeitig feststellen zu können. Nachfolgend werden die Schäden in Tiefgaragen erläutert und darauf aufbauend die bei Abnahme zu kontrollierenden Problempunkte angeführt. Die Vorgehensweise bei der Abnahme von Tiefgaragen wird anhand dieser Problempunkte dargestellt. Diese Veröffentlichung basiert auf einem Vortrag am 9. Dingolfinger Baufachtag 2005. Technical aspects of an acceptance of underground garages Underground garages have a serious potential of damages as a result of faulty design and construction. Damages on account of these shortcomings appear within several years , most times after the guarantee period have expired. Acceptance of underground garages therefore means close checking in an early stadium. The paper shows principal damages and lists the main risks of a underground garage, which should be checked during the acceptance. This paper is based on a presentation during the 9th Dingolfinger Baufachtage 2005. [source]


    Design and Characterization of a Rotating Bed System Bioreactor for Tissue Engineering Applications

    BIOTECHNOLOGY PROGRESS, Issue 1 2008
    Fabienne Anton
    The main challenge in the development of bioreactors for tissue engineering is the delivery of a sufficient nutrient and oxygen supply for cell growth in a 3D environment. Thus, a new rotating bed system bioreactor for tissue engineering applications was developed. The system consists of a culture vessel as well as an integrated rotating bed of special porous ceramic discs and a process control unit connected with the reactor to ensure optimal culturing conditions. The aim of the project was the design and construction of a fully equipped rotating bed reactor, and in particular, the characterization and optimization of the system with regard to technical parameters such as mixing time and pH-control to guarantee optimal conditions for cell growth and differentiation. Furthermore, the applicability of the developed system was demonstrated by cultivation of osteoblast precursor cells. The porous structure of the ceramic discs and the external medium circulation loop provide an optimal environment for tissue generation in long-term cultivations. Mass transfer limitations were minimized by the slow rotation, which also provides the cells with sufficient nutrients and oxygen through alternate contact to air and medium. An osteoblast precursor cell line was successfully cultivated in this bioreactor for 28 days. [source]


    Antibodies and Genetically Engineered Related Molecules: Production and Purification

    BIOTECHNOLOGY PROGRESS, Issue 3 2004
    A. Cecília A. Roque
    Antibodies and antibody derivatives constitute 20 % of biopharmaceutical products currently in development, and despite early failures of murine products, chimeric and humanized monoclonal antibodies are now viable therapeutics. A number of genetically engineered antibody constructions have emerged, including molecular hybrids or chimeras that can deliver a powerful toxin to a target such as a tumor cell. However, the general use in clinical practice of antibody therapeutics is dependent not only on the availability of products with required efficacy but also on the costs of therapy. As a rule, a significant percentage (50,80%) of the total manufacturing cost of a therapeutic antibody is incurred during downstream processing. The critical challenges posed by the production of novel antibody therapeutics include improving process economics and efficiency, to reduce costs, and fulfilling increasingly demanding quality criteria for Food and Drug Administration (FDA) approval. It is anticipated that novel affinity-based separations will emerge from the development of synthetic ligands tailored to specific biotechnological needs. These synthetic affinity ligands include peptides obtained by synthesis and screening of peptide combinatorial libraries and artificial non-peptidic ligands generated by a de novo process design and synthesis. The exceptional stability, improved selectivity, and low cost of these ligands can lead to more efficient, less expensive, and safer procedures for antibody purification at manufacturing scales. This review aims to highlight the current trends in the design and construction of genetically engineered antibodies and related molecules, the recombinant systems used for their production, and the development of novel affinity-based strategies for antibody recovery and purification. [source]