Towards robust, fast solutions of elliptic equations on complex domains through HHO discretizations and non-nested multigrid methods

Autor: Daniel Ruiz, Ulrich Rüde, Daniele Antonio Di Pietro, Paul Mycek, Pierre Matalon, Frank Hülsemann

Publikováno v: International Journal for Numerical Methods in Engineering
International Journal for Numerical Methods in Engineering, Wiley, In press, 122 (22), pp.6576-6595. ⟨10.1002/nme.6803⟩

International audience; The use of modern discretization technologies such as Hybrid High-Order (HHO) methods, coupled with appropriate linear solvers, allow for the robust and fast solution of Partial Differential Equations (PDEs). Although efficien

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::eb9c590e76b47de5267ea82a77ee7079
https://hal.archives-ouvertes.fr/hal-03163476

An h-multigrid method for Hybrid High-Order discretizations

Autor: Daniele Antonio Di Pietro, Daniel Ruiz, Pierre Matalon, Paul Mycek, Ulrich Rüde, Frank Hülsemann

Publikováno v: SIAM Journal on Scientific Computing
SIAM Journal on Scientific Computing, Society for Industrial and Applied Mathematics, 2021, pp.S839-S861. ⟨10.1137/20M1342471⟩

International audience; We consider a second order elliptic PDE discretized by the Hybrid High-Order method, for which globally coupled unknowns are located at faces. To efficiently solve the resulting linear system, we propose a geometric multigrid

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::880cb103354b392ceef0d30a5dd8f59e
https://hal.archives-ouvertes.fr/hal-02434411v2/document

Do we excrete what we eat? Analysis of stable nitrogen isotope ratios of human urinary urea

Autor: Wilhelm Schänzer, Frank Hülsemann, Ulrich Flenker, Karsten Koehler

Publikováno v: Rapid Communications in Mass Spectrometry. 31:1221-1227

Rationale Natural stable nitrogen isotope ratios (δ15N values) are frequently used for the determination of provenance and dietary assessment of recent and ancient humans. Although individual δ15N values typically correspond to the dietary δ15N co

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::ccc2bf09ceeb69f084f6abe57020329e
https://doi.org/10.1002/rcm.7891

Case Study: Atypical δ

Autor: Frank, Hülsemann, Vassilios, Gougoulidis, Thomas, Schertel, Gregor, Fusshöller, Ulrich, Flenker, Thomas, Piper, Mario, Thevis

Publikováno v: Drug testing and analysis. 10(11-12)

Isotope ratio mass spectrometry (IRMS) has been established in doping control analysis to identify the endogenous or exogenous origin of a variety of steroidal analytes including the 19-norsteroid metabolite norandrosterone (NorA). NorA can be found

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=pmid________::9f50d6e48080522f2da84667e46ef068
https://pubmed.ncbi.nlm.nih.gov/30230253

Global spatial distributions of nitrogen and carbon stable isotope ratios of modern human hair

Autor: Philip J. H. Dunn, Ulrich Flenker, Sarah Hill, Nicole Scheid, Glen P. Jackson, Andreas Rossmann, Christine Lehn, Wilhelm Schänzer, Frank Hülsemann, Sabine Schneiders

Publikováno v: Rapid Communications in Mass Spectrometry. 29:2111-2121

RATIONALE Natural stable carbon (δ(13)C) and nitrogen isotope ratios (δ(15)N) of humans are related to individual dietary habits and environmental and physiological factors. In forensic science the stable isotope ratios of human remains such as hai

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::2228d85ef5c45c705688258889eb0369
https://doi.org/10.1002/rcm.7370