68 research outputs found
Mischungsentwicklung fĂĽr funktional gradierten Betonbau
Um eine funktionale Gradierung im Betonbau zu erzielen, werden zwei Betonmischungen mit konträren Eigenschaften benötigt. Je nach Herstellungsverfahren sind die Materialzusammensetzung und damit die Verarbeitbarkeit, Dichte und Festigkeit beider Mischungen anzupassen. Grundsätzlich soll dabei eine der beiden Mischungen gute Festigkeitseigenschaften bei minimaler Porosität zeigen und für die Aufgaben des
statischen Lastabtrags geeignet sein. Die zweite Mischung hingegen ist durch einen hohen Luftporenanteil sehr leicht und wenig fest, kann dafür jedoch mit verbesserten Wärmedämmwerten auch bauphysikalische Anforderungen erfüllen. Ziel in einem interdiziplinären Forschungsvorhaben ist, beide Mischungen in unterschiedlichen Verfahren stufenlos und kontinuierlich ineinander zu überführen und somit funktional gradierte Betonbauteile in einem teilautomatisierten Verfahren herzustellen
Zum Gedenken an Otto Graf, universeller Bauforscher in Stuttgart. Abschiedsvorlesung von Prof. Dr.-Ing. H. W. Reinhardt
Inhalt:
Reinhardt, H.-W.: Otto Graf, Rückschau im Licht von heute (Abschiedsvorlesung am 4. Juli 2006), S. 7 - 41; Gehlen, Christoph: Rede des Direktors der Materialprüfungsanstalt Universität Stuttgart (MPA-Stuttgart / Otto-Graf-Institut (FMPA)) zur Verabschiedung von Herrn Prof. Dr.-Ing. H.-W. Reinhardt am 4. Juli 2006, S. 43 - 55; Thielen, Gerd: Kurze Ansprache des stv. Sprechers des Deutschen Ausschusses für Stahlbeton (DAfStb), S. 57 - 59; Eligehausen, Rolf: Ansprache des stv. Geschäftsführenden Institutsdirektors, S. 61 - 67; Fritsch, Dieter: Grußwort des Rektors der Universität Stuttgart aus Anlass der Abschiedsvorlesung von Herrn Prof. Dr.-Ing. Hans-Wolf Reinhardt, S. 69 - 75; Lebenslauf Hans-Wolf Reinhardt, S. 76; Lebenslauf Otto Graf, S. 77; Aus der Presse, S. 78; Die Autoren, S. 7
Application of super absorbent polymers (SAP) in concrete construction—update of RILEM state-of-the-art report
Superabsorbent polymers (SAP) are a new, promising class of chemical admixtures which offer new possibilities in respect of influencing the properties of cement-based materials in the fresh, hardening, and hardened states. Much research work has been done in the last two decades to set the stage for introducing this truly multipurpose agent into the practice of construction. In particular, three RILEM Technical Committees: 196-ICC, 225-SAP and 260-RSC contributed considerably to the related progress by coordinating and combining the efforts of international experts in the field. The major product of the RILEM TC 225-SAP work was the State-of-the-Art Report published in 2012. This comprehensive document covered all topics relevant to the application of SAP as a concrete admixture. Since then further important progress has been made in understanding the working mechanisms of SAP in concrete and the effects of SAP-addition on various concrete properties. The article at hand presents an update on the state-of-the-art and is the concluding document delivered by the RILEM TC 260-RSC
Testing superabsorbent polymer (SAP) sorption properties prior to implementation in concrete: results of a RILEM Round-Robin Test
This article presents the results of a round-robin test performed by 13 international research groups in the framework of the activities of the RILEM Technical Committee 260 RSC "Recommendations for use of superabsorbent polymers in concrete construction''. Two commercially available superabsorbent polymers (SAP) with different chemical compositions and gradings were tested in terms of their kinetics of absorption in different media; demineralized water, cement filtrate solution with a particular cement distributed to every participant and a local cement chosen by the participant. Two absorption test methods were considered; the tea-bag method and the filtration method. The absorption capacity was evaluated as a function of time. The results showed correspondence in behaviour of the SAPs among all participants, but also between the two test methods, even though high scatter was observed at early minutes of testing after immersion. The tea-bag method proved to be more practical in terms of time dependent study, whereby the filtration method showed less variation in the absorption capacity after 24 h. However, absorption followed by intrinsic, ionmediated desorption of a specific SAP sample in the course of time was not detected by the filtration method. This SAP-specific characteristic was only displayed by the tea-bag method. This demonstrates the practical applicability of both test methods, each one having their own strengths and weaknesses at distinct testing times
Comprehensive genomic profiles of small cell lung cancer
We have sequenced the genomes of 110 small cell lung cancers (SCLC), one of the deadliest human cancers. In nearly all the tumours analysed we found bi-allelic inactivation of TP53 and RB1, sometimes by complex genomic rearrangements. Two tumours with wild-type RB1 had evidence of chromothripsis leading to overexpression of cyclin D1 (encoded by the CCND1 gene), revealing an alternative mechanism of Rb1 deregulation. Thus, loss of the tumour suppressors TP53 and RB1 is obligatory in SCLC. We discovered somatic genomic rearrangements of TP73 that create an oncogenic version of this gene, TP73Dex2/3. In rare cases, SCLC tumours exhibited kinase gene mutations, providing a possible therapeutic opportunity for individual patients. Finally, we observed inactivating mutations in NOTCH family genes in 25% of human SCLC. Accordingly, activation of Notch signalling in a pre-clinical SCLC mouse model strikingly reduced the number of tumours and extended the survival of the mutant mice. Furthermore, neuroendocrine gene expression was abrogated by Notch activity in SCLC cells. This first comprehensive study of somatic genome alterations in SCLC uncovers several key biological processes and identifies candidate therapeutic targets in this highly lethal form of cancer
Initial sequencing and analysis of the human genome
The human genome holds an extraordinary trove of information about human development, physiology, medicine and evolution. Here we report the results of an international collaboration to produce and make freely available a draft sequence of the human genome. We also present an initial analysis of the data, describing some of the insights that can be gleaned from the sequence.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62798/1/409860a0.pd
Metacarpal bone loss in patients with rheumatoid arthritis estimated by a new Digital X-ray Radiogrammetry method – initial results
Application of Super Absorbent Polymers (SAP) in Concrete Construction: State-of-the-Art Report Prepared by Technical Committee 225-SAP
This is the state-of-the-art report prepared by the RILEM TC “Application of Super Absorbent Polymers (SAP) in concrete construction”. It gives a comprehensive overview of the properties of SAP, specific water absorption and desorption behaviour of SAP in fresh and hardening concrete, effects of the SAP addition on rheological properties of fresh concrete, changes of cement paste microstructure and mechanical properties of concrete. Furthermore, the key advantages of using SAP are described in detail: the ability of this material to act as an internal curing agent to mitigate autogenous shrinkage of high-performance concrete, the possibility to use SAP as an alternative to air-entrainment agents in order to increase the frost resistance of concrete, and finally, the benefit of steering the rheology of fresh cement-based materials. The final chapter describes the first existing and numerous prospective applications for this new concrete additive
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