103,505 research outputs found
Visco-elastic regularization and strain softening
No full textIn this paper it is intended to verify the capacity of regularization of the numerical
solution of an elasto-plastic problem with linear strain softening. The finite element method
with a displacement approach is used. Drucker-Prager yield criteria is considered. The radial
return method is used for the integration of the elasto-plastic constitutive relations. An elastovisco-
plastic scheme is used to regularize the numerical solution. Two constitutive laws have
been developed and implemented in a FE-program, the first represent the radial return
method applied to Drucker-Prager yield criteria and the second is a time integration
procedure for the Maxwell visco-elastic model. Attention is paid to finite deformations. An
associative plastic flow is considered in the Drucker-Prager elasto-plastic model. The
algorithms are tested in two problems with softening. Figures showing the capability of the
algorithms to regularize the solution are presented
Formation of oak lactone from 3-methyl-4-hydroxyoctanoic acid and its 4-O-beta-D-glucopyranosides
No full textK. L. Wilkinson, G. M. Elsey, R. H. Prager, A. P. Pollnitz and M. A. Sefton.http://trove.nla.gov.au/work/2738158
Challenging chemoresistant metastatic colorectal cancer: Therapeutic strategies from the clinic and from the laboratory
No full textAs survival has improved for patients with metastatic colorectal cancer (mCRC), there is an increasing need for effective and well-tolerated third-line and subsequent-lines of treatment. Despite recent advances with the development of new-targeted therapies in this setting, there remains an unmet need to exploit oncogenic drivers of colorectal cancer and overcome acquired resistance. Potential treatment strategies include revisiting old targets such as human epidermal growth factor receptor 2, RAS, and BRAF and investigating new targets such as c-MET, the PI3 kinase, and Wnt pathways, and also the use of immune-checkpoint inhibitors. Here, we review recent phase III trials exploring approved agents, early trials investigating new drugs for chemorefractory mCRC, and the potential of capturing tumour dynamics during its evolution by liquid biopsy analysis
Wappenbuch Richental V: Die Prager Handschrift
No full textVier Päpste, ungewöhnlich einträchtig nebeneinander: Die Wappen der "Konzilspäpste" (Pr, fol. 245v) Die zweispaltig angelegte Prager Papierhandschrift (Sigle: Pr; zu den Siglen siehe hier) stammt, wie G und St1, aus der Werkstatt Gebhard Dachers und ist von diesem selbst auf 1464 datiert worden. Aufgrund des ähnlichen Textes und v.a. der Erzählperspektive werden A und Pr zusammen als „Handschriftengruppe I“ gezählt (Kautzsch 1894). Die Ähnlichkeit zu A ist auch im Wappenbuchteil offensichtlic..
Bibliographie Hilarion G. Petzold 1958 – 2009 mit Anhang als Einführung
No full textDieses Archiv enthält die Gesamtbibliographie der Werke des Autors nebst einiger Texte „Über H. G. Petzold“ im Schlussteil der Bibliographie sowie einen Anhang mit einer Einführung in die Architektur des Werkes in seinem wissenslogischen Aufbau als Ausarbeitung seines „Tree of Science Modells“ (2007).This archive contains the complete bibliography of the author and some texts about H. G. Petzold, moreover an epilogue with an introduction to the architecture of the works in its epistemological structure and composition and as an elaborations of Petzold’s „Tree of Science Modell (2007).https://www.fpi-publikation.de/polyloge/01-2009-petzold-h-g-gesamtbibliographie-h-g-petzold-1958-2009-updating-november2009/peerReviewedpublishedVersio
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Constrained optimal layouts through prager-shield criteria
No full textThe Prager-Shield condition is used for determining optimal layouts with an upper limit on the member sizes. The above extended theory is then applied to grillages and it is shown that both the primal problem (stress-field) and the dual problem (strain-field) furnish the same minimum cost. It is also concluded that an upper constraint on the generalized stresses often results in impulse-like concentrations in the optimal strain-field. The above results complement recent work by Strang and Kohn
Quasi-single helicity spectra in the Madison Symmetric Torus
No full textEvidence of a self-organized collapse towards a narrow spectrum of magnetic instabilities in the Madison Symmetric Torus [R. N. Dexter, D. W. Kerst, T. W. Lovell, S. C. Prager, and J. C. Sprott, Fusion Technol. 19, 131 (1991)] reversed field pinch device is presented. In this collapsed state, dubbed quasi-single helicity (QSH), the spectrum of magnetic modes condenses spontaneously to one dominant mode more completely than ever before observed. The amplitudes of all but the largest of the m=1 modes decrease in QSH states. New results about thermal features of QSH spectra and the identification of global control parameters for their onset are also discussed. (C) 2002 American Institute of Physics
Prager-structures: arch-grids and cable networks of optimal layout
No full textThis paper is concerned with a new class of optimal structures termed 'Prager-structures' which satisfy the following design criteria: all members have the same constant stress throughout the system and the total structural weight is minimized with respect to the member layout as well as the location of external loads along their line of action. In contrast to Michell frames, Prager structures (i) must have member forces of the same sign throughout; and (ii) have been found to constitute 'surface structures' whose middle surface contains the centroidal axis of all members. Using Prager's theories, global optimality is established for broad classes of loading and boundary conditions. The results are compared with those for Michell structures and optimal grillages
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