[{"issue":"21","status":"public","intvolume":"       117","doi":"10.1073/pnas.1913716117","isi":1,"type":"journal_article","publication_status":"published","author":[{"last_name":"Xu","full_name":"Xu, Duo","id":"3454D55E-F248-11E8-B48F-1D18A9856A87","first_name":"Duo"},{"first_name":"Atul","id":"2A2006B2-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0002-3072-5999","full_name":"Varshney, Atul","last_name":"Varshney"},{"last_name":"Ma","first_name":"Xingyu","id":"34BADBA6-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0002-0179-9737","full_name":"Ma, Xingyu"},{"last_name":"Song","first_name":"Baofang","full_name":"Song, Baofang"},{"first_name":"Michael","id":"3BE60946-F248-11E8-B48F-1D18A9856A87","full_name":"Riedl, Michael","orcid":"0000-0003-4844-6311","last_name":"Riedl"},{"last_name":"Avila","first_name":"Marc","full_name":"Avila, Marc"},{"last_name":"Hof","full_name":"Hof, Björn","orcid":"0000-0003-2057-2754","id":"3A374330-F248-11E8-B48F-1D18A9856A87","first_name":"Björn"}],"article_processing_charge":"No","quality_controlled":"1","pmid":1,"related_material":{"link":[{"description":"News on IST Homepage","url":"https://ist.ac.at/en/news/blood-flows-more-turbulent-than-previously-expected/","relation":"press_release"}],"record":[{"status":"public","id":"12726","relation":"dissertation_contains"},{"relation":"dissertation_contains","status":"public","id":"14530"}]},"citation":{"ieee":"D. Xu <i>et al.</i>, “Nonlinear hydrodynamic instability and turbulence in pulsatile flow,” <i>Proceedings of the National Academy of Sciences of the United States of America</i>, vol. 117, no. 21. National Academy of Sciences, pp. 11233–11239, 2020.","mla":"Xu, Duo, et al. “Nonlinear Hydrodynamic Instability and Turbulence in Pulsatile Flow.” <i>Proceedings of the National Academy of Sciences of the United States of America</i>, vol. 117, no. 21, National Academy of Sciences, 2020, pp. 11233–39, doi:<a href=\"https://doi.org/10.1073/pnas.1913716117\">10.1073/pnas.1913716117</a>.","ista":"Xu D, Varshney A, Ma X, Song B, Riedl M, Avila M, Hof B. 2020. Nonlinear hydrodynamic instability and turbulence in pulsatile flow. Proceedings of the National Academy of Sciences of the United States of America. 117(21), 11233–11239.","ama":"Xu D, Varshney A, Ma X, et al. Nonlinear hydrodynamic instability and turbulence in pulsatile flow. <i>Proceedings of the National Academy of Sciences of the United States of America</i>. 2020;117(21):11233-11239. doi:<a href=\"https://doi.org/10.1073/pnas.1913716117\">10.1073/pnas.1913716117</a>","short":"D. Xu, A. Varshney, X. Ma, B. Song, M. Riedl, M. Avila, B. Hof, Proceedings of the National Academy of Sciences of the United States of America 117 (2020) 11233–11239.","apa":"Xu, D., Varshney, A., Ma, X., Song, B., Riedl, M., Avila, M., &#38; Hof, B. (2020). Nonlinear hydrodynamic instability and turbulence in pulsatile flow. <i>Proceedings of the National Academy of Sciences of the United States of America</i>. National Academy of Sciences. <a href=\"https://doi.org/10.1073/pnas.1913716117\">https://doi.org/10.1073/pnas.1913716117</a>","chicago":"Xu, Duo, Atul Varshney, Xingyu Ma, Baofang Song, Michael Riedl, Marc Avila, and Björn Hof. “Nonlinear Hydrodynamic Instability and Turbulence in Pulsatile Flow.” <i>Proceedings of the National Academy of Sciences of the United States of America</i>. National Academy of Sciences, 2020. <a href=\"https://doi.org/10.1073/pnas.1913716117\">https://doi.org/10.1073/pnas.1913716117</a>."},"department":[{"_id":"BjHo"}],"project":[{"call_identifier":"FWF","name":"Instabilities in pulsating pipe flow in complex fluids","_id":"238B8092-32DE-11EA-91FC-C7463DDC885E","grant_number":"I04188"},{"grant_number":"754411","_id":"260C2330-B435-11E9-9278-68D0E5697425","call_identifier":"H2020","name":"ISTplus - Postdoctoral Fellowships"}],"_id":"7932","oa_version":"Preprint","oa":1,"volume":117,"publisher":"National Academy of Sciences","external_id":{"pmid":["32393637"],"isi":["000536797100014"],"arxiv":["2005.11190"]},"arxiv":1,"day":"26","title":"Nonlinear hydrodynamic instability and turbulence in pulsatile flow","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","article_type":"original","scopus_import":"1","year":"2020","ec_funded":1,"month":"05","date_published":"2020-05-26T00:00:00Z","date_created":"2020-06-07T22:00:51Z","publication":"Proceedings of the National Academy of Sciences of the United States of America","date_updated":"2026-04-07T13:29:13Z","page":"11233-11239","abstract":[{"text":"Pulsating flows through tubular geometries are laminar provided that velocities are moderate. This in particular is also believed to apply to cardiovascular flows where inertial forces are typically too low to sustain turbulence. On the other hand, flow instabilities and fluctuating shear stresses are held responsible for a variety of cardiovascular diseases. Here we report a nonlinear instability mechanism for pulsating pipe flow that gives rise to bursts of turbulence at low flow rates. Geometrical distortions of small, yet finite, amplitude are found to excite a state consisting of helical vortices during flow deceleration. The resulting flow pattern grows rapidly in magnitude, breaks down into turbulence, and eventually returns to laminar when the flow accelerates. This scenario causes shear stress fluctuations and flow reversal during each pulsation cycle. Such unsteady conditions can adversely affect blood vessels and have been shown to promote inflammation and dysfunction of the shear stress-sensitive endothelial cell layer.","lang":"eng"}],"publication_identifier":{"eissn":["1091-6490"],"issn":["0027-8424"]},"main_file_link":[{"url":"https://arxiv.org/abs/2005.11190","open_access":"1"}],"language":[{"iso":"eng"}]},{"alternative_title":["ISTA Thesis"],"language":[{"iso":"eng"}],"corr_author":"1","file":[{"date_created":"2020-09-09T11:06:27Z","access_level":"closed","file_size":65194814,"relation":"source_file","date_updated":"2021-09-11T22:30:05Z","embargo_to":"open_access","file_id":"8351","content_type":"application/vnd.openxmlformats-officedocument.wordprocessingml.document","file_name":"Shayan-Thesis-Final.docx","creator":"sshamip","checksum":"6e47871c74f85008b9876112eb3fcfa1"},{"access_level":"open_access","date_created":"2020-09-09T11:06:13Z","file_size":23729605,"relation":"main_file","date_updated":"2021-09-11T22:30:05Z","file_id":"8352","content_type":"application/pdf","embargo":"2021-09-10","creator":"sshamip","checksum":"1b44c57f04d7e8a6fe41b1c9c55a52a3","file_name":"Shayan-Thesis-Final.pdf"}],"abstract":[{"lang":"eng","text":"Cytoplasm is a gel-like crowded environment composed of tens of thousands of macromolecules, organelles, cytoskeletal networks and cytosol. The structure of the cytoplasm is thought to be highly organized and heterogeneous due to the crowding of its constituents and their effective compartmentalization. In such an environment, the diffusive dynamics of the molecules is very restricted, an effect that is further amplified by clustering and anchoring of molecules. Despite the jammed nature of the cytoplasm at the microscopic scale, large-scale reorganization of cytoplasm is essential for important cellular functions, such as nuclear positioning and cell division. How such mesoscale reorganization of the cytoplasm is achieved, especially for very large cells such as oocytes or syncytial tissues that can span hundreds of micrometers in size, has only begun to be understood.\r\nIn this thesis, I focus on the recent advances in elucidating the molecular, cellular and biophysical principles underlying cytoplasmic organization across different scales, structures and species. First, I outline which of these principles have been identified by reductionist approaches, such as in vitro reconstitution assays, where boundary conditions and components can be modulated at ease. I then describe how the theoretical and experimental framework established in these reduced systems have been applied to their more complex in vivo counterparts, in particular oocytes and embryonic syncytial structures, and discuss how such complex biological systems can initiate symmetry breaking and establish patterning.\r\nSpecifically, I examine an example of large-scale reorganizations taking place in zebrafish embryos, where extensive cytoplasmic streaming leads to the segregation of cytoplasm from yolk granules along the animal-vegetal axis of the embryo. Using biophysical experimentation and theory, I investigate the forces underlying this process, to show that this process does not rely on cortical actin reorganization, as previously thought, but instead on a cell-cycle-dependent bulk actin polymerization wave traveling from the animal to the vegetal pole of the embryo. This wave functions in segregation by both pulling cytoplasm animally and pushing yolk granules vegetally. Cytoplasm pulling is mediated by bulk actin network flows exerting friction forces on the cytoplasm, while yolk granule pushing is achieved by a mechanism closely resembling actin comet formation on yolk granules. This study defines a novel role of bulk actin polymerization waves in embryo polarization via cytoplasmic segregation. Lastly, I describe the cytoplasmic reorganizations taking place during zebrafish oocyte maturation, where the initial segregation of the cytoplasm and yolk granules occurs. Here, I demonstrate a previously uncharacterized wave of microtubule aster formation, traveling the oocyte along the animal-vegetal axis. Further research is required to determine the role of such microtubule structures in cytoplasmic reorganizations therein.\r\nCollectively, these studies provide further evidence for the coupling between cell cytoskeleton and cell cycle machinery, which can underlie a core self-organizing mechanism for orchestrating large-scale reorganizations in a cell-cycle-tunable manner, where the modulations of the force-generating machinery and cytoplasmic mechanics can be harbored to fulfill cellular functions."}],"publication_identifier":{"issn":["2663-337X"]},"degree_awarded":"PhD","ddc":["570"],"page":"107","date_created":"2020-09-09T11:12:10Z","date_updated":"2025-09-11T07:08:52Z","date_published":"2020-09-09T00:00:00Z","month":"09","year":"2020","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","title":"Bulk actin dynamics drive phase segregation in zebrafish oocytes ","day":"09","publisher":"Institute of Science and Technology Austria","acknowledged_ssus":[{"_id":"PreCl"},{"_id":"Bio"},{"_id":"EM-Fac"}],"file_date_updated":"2021-09-11T22:30:05Z","_id":"8350","oa":1,"oa_version":"None","department":[{"_id":"BjHo"},{"_id":"CaHe"}],"citation":{"ista":"Shamipour S. 2020. Bulk actin dynamics drive phase segregation in zebrafish oocytes . Institute of Science and Technology Austria.","mla":"Shamipour, Shayan. <i>Bulk Actin Dynamics Drive Phase Segregation in Zebrafish Oocytes </i>. Institute of Science and Technology Austria, 2020, doi:<a href=\"https://doi.org/10.15479/AT:ISTA:8350\">10.15479/AT:ISTA:8350</a>.","ieee":"S. Shamipour, “Bulk actin dynamics drive phase segregation in zebrafish oocytes ,” Institute of Science and Technology Austria, 2020.","chicago":"Shamipour, Shayan. “Bulk Actin Dynamics Drive Phase Segregation in Zebrafish Oocytes .” Institute of Science and Technology Austria, 2020. <a href=\"https://doi.org/10.15479/AT:ISTA:8350\">https://doi.org/10.15479/AT:ISTA:8350</a>.","ama":"Shamipour S. Bulk actin dynamics drive phase segregation in zebrafish oocytes . 2020. doi:<a href=\"https://doi.org/10.15479/AT:ISTA:8350\">10.15479/AT:ISTA:8350</a>","short":"S. Shamipour, Bulk Actin Dynamics Drive Phase Segregation in Zebrafish Oocytes , Institute of Science and Technology Austria, 2020.","apa":"Shamipour, S. (2020). <i>Bulk actin dynamics drive phase segregation in zebrafish oocytes </i>. Institute of Science and Technology Austria. <a href=\"https://doi.org/10.15479/AT:ISTA:8350\">https://doi.org/10.15479/AT:ISTA:8350</a>"},"supervisor":[{"id":"39427864-F248-11E8-B48F-1D18A9856A87","first_name":"Carl-Philipp J","full_name":"Heisenberg, Carl-Philipp J","orcid":"0000-0002-0912-4566","last_name":"Heisenberg"},{"id":"3A374330-F248-11E8-B48F-1D18A9856A87","first_name":"Björn","orcid":"0000-0003-2057-2754","full_name":"Hof, Björn","last_name":"Hof"}],"related_material":{"record":[{"relation":"part_of_dissertation","status":"public","id":"7001"},{"id":"6508","status":"public","relation":"part_of_dissertation"},{"relation":"part_of_dissertation","id":"735","status":"public"},{"relation":"part_of_dissertation","id":"661","status":"public"}]},"article_processing_charge":"No","author":[{"full_name":"Shamipour, Shayan","id":"40B34FE2-F248-11E8-B48F-1D18A9856A87","first_name":"Shayan","last_name":"Shamipour"}],"publication_status":"published","type":"dissertation","doi":"10.15479/AT:ISTA:8350","has_accepted_license":"1","status":"public","acknowledgement":"I would have had no fish and hence no results without our wonderful fish facility crew, Verena Mayer, Eva Schlegl, Andreas Mlak and Matthias Nowak. Special thanks to Verena for being always happy to help and dealing with our chaotic schedules in the lab. Danke auch, Verena, für deine Geduld, mit mir auf Deutsch zu sprechen. Das hat mir sehr geholfen.\r\nSpecial thanks to the Bioimaging and EM facilities at IST Austria for supporting us every day. Very special thanks would go to Robert Hauschild for his continuous support on data analysis and also to Jack Merrin for designing and building microfabricated chambers for the project and for the various discussions on making zebrafish extracts."},{"degree_awarded":"PhD","language":[{"iso":"eng"}],"alternative_title":["ISTA Thesis"],"corr_author":"1","file":[{"embargo_to":"open_access","access_level":"closed","date_created":"2020-01-12T15:57:14Z","date_updated":"2021-01-13T23:30:05Z","relation":"source_file","file_size":26640830,"creator":"dscarsel","checksum":"4df1ab24e9896635106adde5a54615bf","file_name":"2020_Scarselli_Thesis.zip","file_id":"7259","content_type":"application/zip"},{"file_size":8515844,"date_updated":"2021-01-13T23:30:05Z","relation":"main_file","date_created":"2020-01-12T15:56:14Z","access_level":"open_access","checksum":"48659ab98e3414293c7a721385c2fd1c","creator":"dscarsel","file_name":"2020_Scarselli_Thesis.pdf","content_type":"application/pdf","file_id":"7260","embargo":"2021-01-12"}],"abstract":[{"lang":"eng","text":"Many flows encountered in nature and applications are characterized by a chaotic motion known as turbulence. Turbulent flows generate intense friction with pipe walls and are responsible for considerable amounts of energy losses at world scale. The nature of turbulent friction and techniques aimed at reducing it have been subject of extensive research over the last century, but no definite answer has been found yet. In this thesis we show that in pipes at moderate turbulent Reynolds numbers friction is better described by the power law first introduced by Blasius and not by the Prandtl–von Kármán formula. At higher Reynolds numbers, large scale motions gradually become more important in the flow and can be related to the change in scaling of friction. Next, we present a series of new techniques that can relaminarize turbulence by suppressing a key mechanism that regenerates it at walls, the lift–up effect. In addition, we investigate the process of turbulence decay in several experiments and discuss the drag reduction potential. Finally, we examine the behavior of friction under pulsating conditions inspired by the human heart cycle and we show that under such circumstances turbulent friction can be reduced to produce energy savings."}],"publication_identifier":{"issn":["2663-337X"]},"year":"2020","user_id":"ba8df636-2132-11f1-aed0-ed93e2281fdd","title":"New approaches to reduce friction in turbulent pipe flow","day":"13","ddc":["532"],"page":"174","date_created":"2020-01-12T16:07:26Z","date_updated":"2026-04-08T07:28:22Z","date_published":"2020-01-13T00:00:00Z","ec_funded":1,"month":"01","file_date_updated":"2021-01-13T23:30:05Z","oa":1,"_id":"7258","oa_version":"None","department":[{"_id":"BjHo"}],"citation":{"ama":"Scarselli D. New approaches to reduce friction in turbulent pipe flow. 2020. doi:<a href=\"https://doi.org/10.15479/AT:ISTA:7258\">10.15479/AT:ISTA:7258</a>","apa":"Scarselli, D. (2020). <i>New approaches to reduce friction in turbulent pipe flow</i>. Institute of Science and Technology Austria. <a href=\"https://doi.org/10.15479/AT:ISTA:7258\">https://doi.org/10.15479/AT:ISTA:7258</a>","short":"D. Scarselli, New Approaches to Reduce Friction in Turbulent Pipe Flow, Institute of Science and Technology Austria, 2020.","chicago":"Scarselli, Davide. “New Approaches to Reduce Friction in Turbulent Pipe Flow.” Institute of Science and Technology Austria, 2020. <a href=\"https://doi.org/10.15479/AT:ISTA:7258\">https://doi.org/10.15479/AT:ISTA:7258</a>.","ieee":"D. Scarselli, “New approaches to reduce friction in turbulent pipe flow,” Institute of Science and Technology Austria, 2020.","ista":"Scarselli D. 2020. New approaches to reduce friction in turbulent pipe flow. Institute of Science and Technology Austria.","mla":"Scarselli, Davide. <i>New Approaches to Reduce Friction in Turbulent Pipe Flow</i>. Institute of Science and Technology Austria, 2020, doi:<a href=\"https://doi.org/10.15479/AT:ISTA:7258\">10.15479/AT:ISTA:7258</a>."},"project":[{"_id":"25152F3A-B435-11E9-9278-68D0E5697425","grant_number":"306589","name":"Decoding the complexity of turbulence at its origin","call_identifier":"FP7"},{"_id":"25104D44-B435-11E9-9278-68D0E5697425","grant_number":"737549","call_identifier":"H2020","name":"Eliminating turbulence in oil pipelines"},{"_id":"25136C54-B435-11E9-9278-68D0E5697425","grant_number":"HO 4393/1-2","name":"Experimental studies of the turbulence transition and transport processes in turbulent Taylor-Couette currents"}],"publisher":"Institute of Science and Technology Austria","doi":"10.15479/AT:ISTA:7258","has_accepted_license":"1","status":"public","OA_place":"publisher","supervisor":[{"first_name":"Björn","id":"3A374330-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0003-2057-2754","full_name":"Hof, Björn","last_name":"Hof"}],"related_material":{"record":[{"relation":"part_of_dissertation","status":"public","id":"422"},{"id":"461","status":"public","relation":"part_of_dissertation"},{"status":"public","id":"6228","relation":"part_of_dissertation"},{"status":"public","id":"6486","relation":"part_of_dissertation"}]},"article_processing_charge":"No","publication_status":"published","author":[{"full_name":"Scarselli, Davide","orcid":"0000-0001-5227-4271","first_name":"Davide","id":"40315C30-F248-11E8-B48F-1D18A9856A87","last_name":"Scarselli"}],"type":"dissertation"},{"language":[{"iso":"eng"}],"abstract":[{"lang":"eng","text":"We consider the motion of a droplet bouncing on a vibrating bath of the same fluid in the presence of a central potential. We formulate a rotation symmetry-reduced description of this system, which allows for the straightforward application of dynamical systems theory tools. As an illustration of the utility of the symmetry reduction, we apply it to a model of the pilot-wave system with a central harmonic force. We begin our analysis by identifying local bifurcations and the onset of chaos. We then describe the emergence of chaotic regions and their merging bifurcations, which lead to the formation of a global attractor. In this final regime, the droplet’s angular momentum spontaneously changes its sign as observed in the experiments of Perrard et al."}],"publication_identifier":{"eissn":["1089-7682"],"issn":["1054-1500"]},"main_file_link":[{"url":"https://arxiv.org/abs/1812.09011","open_access":"1"}],"date_created":"2019-01-23T08:35:09Z","date_updated":"2023-08-25T10:16:11Z","publication":"Chaos: An Interdisciplinary Journal of Nonlinear Science","month":"01","date_published":"2019-01-22T00:00:00Z","user_id":"4359f0d1-fa6c-11eb-b949-802e58b17ae8","article_type":"original","year":"2019","scopus_import":"1","day":"22","title":"State space geometry of the chaotic pilot-wave hydrodynamics","arxiv":1,"publisher":"AIP Publishing","external_id":{"isi":["000457409100028"],"arxiv":["1812.09011"]},"_id":"5878","oa":1,"oa_version":"Preprint","volume":29,"department":[{"_id":"BjHo"}],"citation":{"short":"N.B. Budanur, M. Fleury, Chaos: An Interdisciplinary Journal of Nonlinear Science 29 (2019).","ama":"Budanur NB, Fleury M. State space geometry of the chaotic pilot-wave hydrodynamics. <i>Chaos: An Interdisciplinary Journal of Nonlinear Science</i>. 2019;29(1). doi:<a href=\"https://doi.org/10.1063/1.5058279\">10.1063/1.5058279</a>","apa":"Budanur, N. B., &#38; Fleury, M. (2019). State space geometry of the chaotic pilot-wave hydrodynamics. <i>Chaos: An Interdisciplinary Journal of Nonlinear Science</i>. AIP Publishing. <a href=\"https://doi.org/10.1063/1.5058279\">https://doi.org/10.1063/1.5058279</a>","chicago":"Budanur, Nazmi B, and Marc Fleury. “State Space Geometry of the Chaotic Pilot-Wave Hydrodynamics.” <i>Chaos: An Interdisciplinary Journal of Nonlinear Science</i>. AIP Publishing, 2019. <a href=\"https://doi.org/10.1063/1.5058279\">https://doi.org/10.1063/1.5058279</a>.","ieee":"N. B. Budanur and M. Fleury, “State space geometry of the chaotic pilot-wave hydrodynamics,” <i>Chaos: An Interdisciplinary Journal of Nonlinear Science</i>, vol. 29, no. 1. AIP Publishing, 2019.","mla":"Budanur, Nazmi B., and Marc Fleury. “State Space Geometry of the Chaotic Pilot-Wave Hydrodynamics.” <i>Chaos: An Interdisciplinary Journal of Nonlinear Science</i>, vol. 29, no. 1, 013122, AIP Publishing, 2019, doi:<a href=\"https://doi.org/10.1063/1.5058279\">10.1063/1.5058279</a>.","ista":"Budanur NB, Fleury M. 2019. State space geometry of the chaotic pilot-wave hydrodynamics. Chaos: An Interdisciplinary Journal of Nonlinear Science. 29(1), 013122."},"quality_controlled":"1","article_processing_charge":"No","related_material":{"link":[{"relation":"erratum","url":"https://aip.scitation.org/doi/abs/10.1063/1.5097157"}]},"article_number":"013122","type":"journal_article","publication_status":"published","author":[{"orcid":"0000-0003-0423-5010","full_name":"Budanur, Nazmi B","first_name":"Nazmi B","id":"3EA1010E-F248-11E8-B48F-1D18A9856A87","last_name":"Budanur"},{"first_name":"Marc","full_name":"Fleury, Marc","last_name":"Fleury"}],"intvolume":"        29","doi":"10.1063/1.5058279","isi":1,"issue":"1","status":"public"},{"oa":1,"_id":"5943","oa_version":"Preprint","volume":863,"project":[{"name":"ISTplus - Postdoctoral Fellowships","call_identifier":"H2020","_id":"260C2330-B435-11E9-9278-68D0E5697425","grant_number":"754411"}],"citation":{"chicago":"Klotz, Lukasz, Konrad Gumowski, and José Eduardo Wesfreid. “Experiments on a Jet in a Crossflow in the Low-Velocity-Ratio Regime.” <i>Journal of Fluid Mechanics</i>. Cambridge University Press, 2019. <a href=\"https://doi.org/10.1017/jfm.2018.974\">https://doi.org/10.1017/jfm.2018.974</a>.","apa":"Klotz, L., Gumowski, K., &#38; Wesfreid, J. E. (2019). Experiments on a jet in a crossflow in the low-velocity-ratio regime. <i>Journal of Fluid Mechanics</i>. Cambridge University Press. <a href=\"https://doi.org/10.1017/jfm.2018.974\">https://doi.org/10.1017/jfm.2018.974</a>","short":"L. Klotz, K. Gumowski, J.E. Wesfreid, Journal of Fluid Mechanics 863 (2019) 386–406.","ama":"Klotz L, Gumowski K, Wesfreid JE. Experiments on a jet in a crossflow in the low-velocity-ratio regime. <i>Journal of Fluid Mechanics</i>. 2019;863:386-406. doi:<a href=\"https://doi.org/10.1017/jfm.2018.974\">10.1017/jfm.2018.974</a>","mla":"Klotz, Lukasz, et al. “Experiments on a Jet in a Crossflow in the Low-Velocity-Ratio Regime.” <i>Journal of Fluid Mechanics</i>, vol. 863, Cambridge University Press, 2019, pp. 386–406, doi:<a href=\"https://doi.org/10.1017/jfm.2018.974\">10.1017/jfm.2018.974</a>.","ista":"Klotz L, Gumowski K, Wesfreid JE. 2019. Experiments on a jet in a crossflow in the low-velocity-ratio regime. Journal of Fluid Mechanics. 863, 386–406.","ieee":"L. Klotz, K. Gumowski, and J. E. Wesfreid, “Experiments on a jet in a crossflow in the low-velocity-ratio regime,” <i>Journal of Fluid Mechanics</i>, vol. 863. Cambridge University Press, pp. 386–406, 2019."},"department":[{"_id":"BjHo"}],"arxiv":1,"external_id":{"isi":["000526029100016"],"arxiv":["1902.07931"]},"publisher":"Cambridge University Press","doi":"10.1017/jfm.2018.974","intvolume":"       863","isi":1,"status":"public","article_processing_charge":"No","quality_controlled":"1","type":"journal_article","publication_status":"published","author":[{"last_name":"Klotz","full_name":"Klotz, Lukasz","orcid":"0000-0003-1740-7635","id":"2C9AF1C2-F248-11E8-B48F-1D18A9856A87","first_name":"Lukasz"},{"last_name":"Gumowski","first_name":"Konrad","full_name":"Gumowski, Konrad"},{"full_name":"Wesfreid, José Eduardo","first_name":"José Eduardo","last_name":"Wesfreid"}],"language":[{"iso":"eng"}],"abstract":[{"text":"The hairpin instability of a jet in a crossflow (JICF) for a low jet-to-crossflow velocity ratio is investigated experimentally for a velocity ratio range of R ∈ (0.14, 0.75) and crossflow Reynolds numbers ReD ∈ (260, 640). From spectral analysis we characterize the Strouhal number and amplitude of the hairpin instability as a function of R and ReD. We demonstrate that the dynamics of the hairpins is well described by the Landau model, and, hence, that the instability occurs through Hopf bifurcation, similarly to other hydrodynamical oscillators such as wake behind different bluff bodies. Using the Landau model, we determine the precise threshold values of hairpin shedding. We also study the spatial dependence of this hydrodynamical instability, which shows a global behaviour.","lang":"eng"}],"main_file_link":[{"open_access":"1","url":"https://arxiv.org/abs/1902.07931"}],"user_id":"4359f0d1-fa6c-11eb-b949-802e58b17ae8","year":"2019","article_type":"original","scopus_import":"1","day":"25","title":"Experiments on a jet in a crossflow in the low-velocity-ratio regime","publication":"Journal of Fluid Mechanics","date_updated":"2025-04-14T07:43:59Z","date_created":"2019-02-10T22:59:15Z","page":"386-406","month":"03","ec_funded":1,"date_published":"2019-03-25T00:00:00Z"},{"ec_funded":1,"month":"02","date_published":"2019-02-08T00:00:00Z","date_created":"2019-02-15T07:10:46Z","publication":"Nature Communications","date_updated":"2025-04-14T07:43:46Z","ddc":["530"],"day":"08","title":"Elastic alfven waves in elastic turbulence","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","scopus_import":"1","article_type":"original","year":"2019","abstract":[{"lang":"eng","text":"Speed of sound waves in gases and liquids are governed by the compressibility of the medium. There exists another type of non-dispersive wave where the wave speed depends on stress instead of elasticity of the medium. A well-known example is the Alfven wave, which propagates through plasma permeated by a magnetic field with the speed determined by magnetic tension. An elastic analogue of Alfven waves has been predicted in a flow of dilute polymer solution where the elastic stress of the stretching polymers determines the elastic wave speed. Here we present quantitative evidence of elastic Alfven waves in elastic turbulence of a viscoelastic creeping flow between two obstacles in channel flow. The key finding in the experimental proof is a nonlinear dependence of the elastic wave speed cel on the Weissenberg number Wi, which deviates from predictions based on a model of linear polymer elasticity."}],"publication_identifier":{"issn":["2041-1723"]},"file":[{"checksum":"d3acf07eaad95ec040d8e8565fc9ac37","creator":"dernst","file_name":"2019_NatureComm_Varshney.pdf","content_type":"application/pdf","file_id":"6015","date_updated":"2020-07-14T12:47:17Z","relation":"main_file","file_size":1331490,"date_created":"2019-02-15T07:15:00Z","access_level":"open_access"}],"corr_author":"1","language":[{"iso":"eng"}],"tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","short":"CC BY (4.0)","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)"},"type":"journal_article","publication_status":"published","author":[{"last_name":"Varshney","id":"2A2006B2-F248-11E8-B48F-1D18A9856A87","first_name":"Atul","orcid":"0000-0002-3072-5999","full_name":"Varshney, Atul"},{"first_name":"Victor","full_name":"Steinberg, Victor","last_name":"Steinberg"}],"quality_controlled":"1","article_processing_charge":"No","pmid":1,"article_number":"652","has_accepted_license":"1","status":"public","intvolume":"        10","doi":"10.1038/s41467-019-08551-0","isi":1,"publisher":"Springer Nature","external_id":{"arxiv":["1902.03763"],"isi":["000458175300001"],"pmid":["30737403"]},"arxiv":1,"department":[{"_id":"BjHo"}],"citation":{"ieee":"A. Varshney and V. Steinberg, “Elastic alfven waves in elastic turbulence,” <i>Nature Communications</i>, vol. 10. Springer Nature, 2019.","mla":"Varshney, Atul, and Victor Steinberg. “Elastic Alfven Waves in Elastic Turbulence.” <i>Nature Communications</i>, vol. 10, 652, Springer Nature, 2019, doi:<a href=\"https://doi.org/10.1038/s41467-019-08551-0\">10.1038/s41467-019-08551-0</a>.","ista":"Varshney A, Steinberg V. 2019. Elastic alfven waves in elastic turbulence. Nature Communications. 10, 652.","short":"A. Varshney, V. Steinberg, Nature Communications 10 (2019).","ama":"Varshney A, Steinberg V. Elastic alfven waves in elastic turbulence. <i>Nature Communications</i>. 2019;10. doi:<a href=\"https://doi.org/10.1038/s41467-019-08551-0\">10.1038/s41467-019-08551-0</a>","apa":"Varshney, A., &#38; Steinberg, V. (2019). Elastic alfven waves in elastic turbulence. <i>Nature Communications</i>. Springer Nature. <a href=\"https://doi.org/10.1038/s41467-019-08551-0\">https://doi.org/10.1038/s41467-019-08551-0</a>","chicago":"Varshney, Atul, and Victor Steinberg. “Elastic Alfven Waves in Elastic Turbulence.” <i>Nature Communications</i>. Springer Nature, 2019. <a href=\"https://doi.org/10.1038/s41467-019-08551-0\">https://doi.org/10.1038/s41467-019-08551-0</a>."},"project":[{"_id":"260C2330-B435-11E9-9278-68D0E5697425","grant_number":"754411","call_identifier":"H2020","name":"ISTplus - Postdoctoral Fellowships"}],"oa_version":"Published Version","_id":"6014","oa":1,"volume":10,"file_date_updated":"2020-07-14T12:47:17Z"},{"tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","short":"CC BY (4.0)","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)"},"publication_identifier":{"issn":["2041-1723"]},"abstract":[{"text":"Electron transport in two-dimensional conducting materials such as graphene, with dominant electron–electron interaction, exhibits unusual vortex flow that leads to a nonlocal current-field relation (negative resistance), distinct from the classical Ohm’s law. The transport behavior of these materials is best described by low Reynolds number hydrodynamics, where the constitutive pressure–speed relation is Stoke’s law. Here we report evidence of such vortices observed in a viscous flow of Newtonian fluid in a microfluidic device consisting of a rectangular cavity—analogous to the electronic system. We extend our experimental observations to elliptic cavities of different eccentricities, and validate them by numerically solving bi-harmonic equation obtained for the viscous flow with no-slip boundary conditions. We verify the existence of a  predicted threshold at which vortices appear. Strikingly, we find that a two-dimensional theoretical model captures the essential features of three-dimensional Stokes flow in experiments.","lang":"eng"}],"file":[{"access_level":"open_access","date_created":"2019-03-05T13:33:04Z","relation":"main_file","file_size":2646391,"date_updated":"2020-07-14T12:47:18Z","file_id":"6070","content_type":"application/pdf","file_name":"2019_NatureComm_Mayzel.pdf","creator":"dernst","checksum":"61192fc49e0d44907c2a4fe384e4b97f"}],"corr_author":"1","language":[{"iso":"eng"}],"day":"26","title":"Stokes flow analogous to viscous electron current in graphene","user_id":"c635000d-4b10-11ee-a964-aac5a93f6ac1","scopus_import":"1","year":"2019","ec_funded":1,"month":"02","date_published":"2019-02-26T00:00:00Z","date_created":"2019-03-05T13:18:30Z","date_updated":"2025-04-14T07:44:00Z","publication":"Nature Communications","ddc":["530","532"],"department":[{"_id":"BjHo"}],"citation":{"chicago":"Mayzel, Jonathan, Victor Steinberg, and Atul Varshney. “Stokes Flow Analogous to Viscous Electron Current in Graphene.” <i>Nature Communications</i>. Springer Nature, 2019. <a href=\"https://doi.org/10.1038/s41467-019-08916-5\">https://doi.org/10.1038/s41467-019-08916-5</a>.","short":"J. Mayzel, V. Steinberg, A. Varshney, Nature Communications 10 (2019).","ama":"Mayzel J, Steinberg V, Varshney A. Stokes flow analogous to viscous electron current in graphene. <i>Nature Communications</i>. 2019;10. doi:<a href=\"https://doi.org/10.1038/s41467-019-08916-5\">10.1038/s41467-019-08916-5</a>","apa":"Mayzel, J., Steinberg, V., &#38; Varshney, A. (2019). Stokes flow analogous to viscous electron current in graphene. <i>Nature Communications</i>. Springer Nature. <a href=\"https://doi.org/10.1038/s41467-019-08916-5\">https://doi.org/10.1038/s41467-019-08916-5</a>","ista":"Mayzel J, Steinberg V, Varshney A. 2019. Stokes flow analogous to viscous electron current in graphene. Nature Communications. 10, 937.","mla":"Mayzel, Jonathan, et al. “Stokes Flow Analogous to Viscous Electron Current in Graphene.” <i>Nature Communications</i>, vol. 10, 937, Springer Nature, 2019, doi:<a href=\"https://doi.org/10.1038/s41467-019-08916-5\">10.1038/s41467-019-08916-5</a>.","ieee":"J. Mayzel, V. Steinberg, and A. Varshney, “Stokes flow analogous to viscous electron current in graphene,” <i>Nature Communications</i>, vol. 10. Springer Nature, 2019."},"project":[{"name":"ISTplus - Postdoctoral Fellowships","call_identifier":"H2020","grant_number":"754411","_id":"260C2330-B435-11E9-9278-68D0E5697425"}],"_id":"6069","oa_version":"Published Version","oa":1,"volume":10,"file_date_updated":"2020-07-14T12:47:18Z","publisher":"Springer Nature","external_id":{"isi":["000459704600001"]},"has_accepted_license":"1","status":"public","intvolume":"        10","doi":"10.1038/s41467-019-08916-5","isi":1,"type":"journal_article","author":[{"first_name":"Jonathan","full_name":"Mayzel, Jonathan","last_name":"Mayzel"},{"last_name":"Steinberg","first_name":"Victor","full_name":"Steinberg, Victor"},{"first_name":"Atul","id":"2A2006B2-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0002-3072-5999","full_name":"Varshney, Atul","last_name":"Varshney"}],"publication_status":"published","article_processing_charge":"No","quality_controlled":"1","article_number":"937"},{"doi":"10.1103/physreve.100.013112","intvolume":"       100","isi":1,"status":"public","issue":"1","article_processing_charge":"No","quality_controlled":"1","article_number":"013112","type":"journal_article","publication_status":"published","author":[{"last_name":"Suri","id":"47A5E706-F248-11E8-B48F-1D18A9856A87","first_name":"Balachandra","full_name":"Suri, Balachandra"},{"last_name":"Pallantla","full_name":"Pallantla, Ravi Kumar","first_name":"Ravi Kumar"},{"full_name":"Schatz, Michael F.","first_name":"Michael F.","last_name":"Schatz"},{"first_name":"Roman O.","full_name":"Grigoriev, Roman O.","last_name":"Grigoriev"}],"oa_version":"Preprint","_id":"6779","oa":1,"volume":100,"project":[{"_id":"25681D80-B435-11E9-9278-68D0E5697425","grant_number":"291734","call_identifier":"FP7","name":"International IST Postdoc Fellowship Programme"}],"citation":{"ista":"Suri B, Pallantla RK, Schatz MF, Grigoriev RO. 2019. Heteroclinic and homoclinic connections in a Kolmogorov-like flow. Physical Review E. 100(1), 013112.","mla":"Suri, Balachandra, et al. “Heteroclinic and Homoclinic Connections in a Kolmogorov-like Flow.” <i>Physical Review E</i>, vol. 100, no. 1, 013112, American Physical Society, 2019, doi:<a href=\"https://doi.org/10.1103/physreve.100.013112\">10.1103/physreve.100.013112</a>.","ieee":"B. Suri, R. K. Pallantla, M. F. Schatz, and R. O. Grigoriev, “Heteroclinic and homoclinic connections in a Kolmogorov-like flow,” <i>Physical Review E</i>, vol. 100, no. 1. American Physical Society, 2019.","chicago":"Suri, Balachandra, Ravi Kumar Pallantla, Michael F. Schatz, and Roman O. Grigoriev. “Heteroclinic and Homoclinic Connections in a Kolmogorov-like Flow.” <i>Physical Review E</i>. American Physical Society, 2019. <a href=\"https://doi.org/10.1103/physreve.100.013112\">https://doi.org/10.1103/physreve.100.013112</a>.","apa":"Suri, B., Pallantla, R. K., Schatz, M. F., &#38; Grigoriev, R. O. (2019). Heteroclinic and homoclinic connections in a Kolmogorov-like flow. <i>Physical Review E</i>. American Physical Society. <a href=\"https://doi.org/10.1103/physreve.100.013112\">https://doi.org/10.1103/physreve.100.013112</a>","ama":"Suri B, Pallantla RK, Schatz MF, Grigoriev RO. Heteroclinic and homoclinic connections in a Kolmogorov-like flow. <i>Physical Review E</i>. 2019;100(1). doi:<a href=\"https://doi.org/10.1103/physreve.100.013112\">10.1103/physreve.100.013112</a>","short":"B. Suri, R.K. Pallantla, M.F. Schatz, R.O. Grigoriev, Physical Review E 100 (2019)."},"department":[{"_id":"BjHo"}],"arxiv":1,"external_id":{"isi":["000477911800012"],"arxiv":["1907.05860"]},"publisher":"American Physical Society","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","scopus_import":"1","article_type":"original","year":"2019","day":"25","title":"Heteroclinic and homoclinic connections in a Kolmogorov-like flow","publication":"Physical Review E","date_updated":"2025-04-15T06:50:28Z","date_created":"2019-08-09T09:40:41Z","ddc":["532"],"month":"07","ec_funded":1,"date_published":"2019-07-25T00:00:00Z","language":[{"iso":"eng"}],"publication_identifier":{"issn":["2470-0045"],"eissn":["2470-0053"]},"abstract":[{"text":"Recent studies suggest that unstable recurrent solutions of the Navier-Stokes equation provide new insights\r\ninto dynamics of turbulent flows. In this study, we compute an extensive network of dynamical connections\r\nbetween such solutions in a weakly turbulent quasi-two-dimensional Kolmogorov flow that lies in the inversion symmetric subspace. In particular, we find numerous isolated heteroclinic connections between different\r\ntypes of solutions—equilibria, periodic, and quasiperiodic orbits—as well as continua of connections forming\r\nhigher-dimensional connecting manifolds. We also compute a homoclinic connection of a periodic orbit and\r\nprovide strong evidence that the associated homoclinic tangle forms the chaotic repeller that underpins transient\r\nturbulence in the symmetric subspace.","lang":"eng"}],"main_file_link":[{"url":"https://arxiv.org/abs/1907.05860","open_access":"1"}]},{"department":[{"_id":"BjHo"}],"citation":{"ista":"Budanur NB, Dogra A, Hof B. 2019. Geometry of transient chaos in streamwise-localized pipe flow turbulence. Physical Review Fluids. 4(10), 102401.","mla":"Budanur, Nazmi B., et al. “Geometry of Transient Chaos in Streamwise-Localized Pipe Flow Turbulence.” <i>Physical Review Fluids</i>, vol. 4, no. 10, American Physical Society, 2019, p. 102401, doi:<a href=\"https://doi.org/10.1103/PhysRevFluids.4.102401\">10.1103/PhysRevFluids.4.102401</a>.","ieee":"N. B. Budanur, A. Dogra, and B. Hof, “Geometry of transient chaos in streamwise-localized pipe flow turbulence,” <i>Physical Review Fluids</i>, vol. 4, no. 10. American Physical Society, p. 102401, 2019.","chicago":"Budanur, Nazmi B, Akshunna Dogra, and Björn Hof. “Geometry of Transient Chaos in Streamwise-Localized Pipe Flow Turbulence.” <i>Physical Review Fluids</i>. American Physical Society, 2019. <a href=\"https://doi.org/10.1103/PhysRevFluids.4.102401\">https://doi.org/10.1103/PhysRevFluids.4.102401</a>.","ama":"Budanur NB, Dogra A, Hof B. Geometry of transient chaos in streamwise-localized pipe flow turbulence. <i>Physical Review Fluids</i>. 2019;4(10):102401. doi:<a href=\"https://doi.org/10.1103/PhysRevFluids.4.102401\">10.1103/PhysRevFluids.4.102401</a>","apa":"Budanur, N. B., Dogra, A., &#38; Hof, B. (2019). Geometry of transient chaos in streamwise-localized pipe flow turbulence. <i>Physical Review Fluids</i>. American Physical Society. <a href=\"https://doi.org/10.1103/PhysRevFluids.4.102401\">https://doi.org/10.1103/PhysRevFluids.4.102401</a>","short":"N.B. Budanur, A. Dogra, B. Hof, Physical Review Fluids 4 (2019) 102401."},"_id":"6978","oa":1,"oa_version":"Preprint","volume":4,"acknowledged_ssus":[{"_id":"ScienComp"}],"publisher":"American Physical Society","external_id":{"isi":["000493510400001"],"arxiv":["1810.02211"]},"arxiv":1,"issue":"10","status":"public","intvolume":"         4","doi":"10.1103/PhysRevFluids.4.102401","isi":1,"type":"journal_article","author":[{"full_name":"Budanur, Nazmi B","orcid":"0000-0003-0423-5010","id":"3EA1010E-F248-11E8-B48F-1D18A9856A87","first_name":"Nazmi B","last_name":"Budanur"},{"last_name":"Dogra","first_name":"Akshunna","full_name":"Dogra, Akshunna"},{"last_name":"Hof","first_name":"Björn","id":"3A374330-F248-11E8-B48F-1D18A9856A87","full_name":"Hof, Björn","orcid":"0000-0003-2057-2754"}],"publication_status":"published","article_processing_charge":"No","quality_controlled":"1","abstract":[{"text":"In  pipes  and  channels,  the  onset  of  turbulence  is  initially  dominated  by  localizedtransients,  which  lead  to  sustained  turbulence  through  their  collective  dynamics.  In  thepresent work, we study numerically the localized turbulence in pipe flow and elucidate astate space structure that gives rise to transient chaos. Starting from the basin boundaryseparating  laminar  and  turbulent  flow,  we  identify  transverse  homoclinic  orbits,  thepresence of which necessitates a homoclinic tangle and chaos. A direct consequence ofthe homoclinic tangle is the fractal nature of the laminar-turbulent boundary, which wasconjectured in various earlier studies. By mapping the transverse intersections between thestable and unstable manifold of a periodic orbit, we identify the gateways that promote anescape from turbulence.","lang":"eng"}],"main_file_link":[{"url":"https://arxiv.org/abs/1810.02211","open_access":"1"}],"language":[{"iso":"eng"}],"day":"01","title":"Geometry of transient chaos in streamwise-localized pipe flow turbulence","user_id":"4359f0d1-fa6c-11eb-b949-802e58b17ae8","year":"2019","article_type":"original","scopus_import":"1","month":"10","date_published":"2019-10-01T00:00:00Z","date_created":"2019-11-04T10:04:01Z","date_updated":"2023-08-30T07:20:03Z","publication":"Physical Review Fluids","page":"102401"},{"language":[{"iso":"eng"}],"abstract":[{"lang":"eng","text":"Polymer additives can substantially reduce the drag of turbulent flows and the upperlimit, the so called “maximum drag reduction” (MDR) asymptote is universal, i.e. inde-pendent of the type of polymer and solvent used. Until recently, the consensus was that,in this limit, flows are in a marginal state where only a minimal level of turbulence activ-ity persists. Observations in direct numerical simulations using minimal sized channelsappeared  to  support  this  view  and  reported  long  “hibernation”  periods  where  turbu-lence is marginalized. In simulations of pipe flow we find that, indeed, with increasingWeissenberg number (Wi), turbulence expresses long periods of hibernation if the domainsize is small. However, with increasing pipe length, the temporal hibernation continuouslyalters to spatio-temporal intermittency and here the flow consists of turbulent puffs sur-rounded by laminar flow. Moreover, upon an increase in Wi, the flow fully relaminarises,in agreement with recent experiments. At even larger Wi, a different instability is en-countered causing a drag increase towards MDR. Our findings hence link earlier minimalflow unit simulations with recent experiments and confirm that the addition of polymersinitially suppresses Newtonian turbulence and leads to a reverse transition. The MDRstate on the other hand results from a separate instability and the underlying dynamicscorresponds to the recently proposed state of elasto-inertial-turbulence (EIT)."}],"publication_identifier":{"eissn":["1469-7645"],"issn":["0022-1120"]},"main_file_link":[{"url":"https://arxiv.org/abs/1808.04080","open_access":"1"}],"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","year":"2019","article_type":"original","scopus_import":"1","day":"10","title":"Dynamics of viscoelastic pipe flow at low Reynolds numbers in the maximum drag reduction limit","publication":"Journal of Fluid Mechanics","date_updated":"2025-05-14T11:21:59Z","date_created":"2020-01-29T16:05:19Z","page":"699-719","month":"09","date_published":"2019-09-10T00:00:00Z","_id":"7397","oa":1,"oa_version":"Preprint","volume":874,"department":[{"_id":"BjHo"}],"citation":{"short":"J.M. Lopez Alonso, G.H. Choueiri, B. Hof, Journal of Fluid Mechanics 874 (2019) 699–719.","apa":"Lopez Alonso, J. M., Choueiri, G. H., &#38; Hof, B. (2019). Dynamics of viscoelastic pipe flow at low Reynolds numbers in the maximum drag reduction limit. <i>Journal of Fluid Mechanics</i>. Cambridge University Press. <a href=\"https://doi.org/10.1017/jfm.2019.486\">https://doi.org/10.1017/jfm.2019.486</a>","ama":"Lopez Alonso JM, Choueiri GH, Hof B. Dynamics of viscoelastic pipe flow at low Reynolds numbers in the maximum drag reduction limit. <i>Journal of Fluid Mechanics</i>. 2019;874:699-719. doi:<a href=\"https://doi.org/10.1017/jfm.2019.486\">10.1017/jfm.2019.486</a>","chicago":"Lopez Alonso, Jose M, George H Choueiri, and Björn Hof. “Dynamics of Viscoelastic Pipe Flow at Low Reynolds Numbers in the Maximum Drag Reduction Limit.” <i>Journal of Fluid Mechanics</i>. Cambridge University Press, 2019. <a href=\"https://doi.org/10.1017/jfm.2019.486\">https://doi.org/10.1017/jfm.2019.486</a>.","ieee":"J. M. Lopez Alonso, G. H. Choueiri, and B. Hof, “Dynamics of viscoelastic pipe flow at low Reynolds numbers in the maximum drag reduction limit,” <i>Journal of Fluid Mechanics</i>, vol. 874. Cambridge University Press, pp. 699–719, 2019.","mla":"Lopez Alonso, Jose M., et al. “Dynamics of Viscoelastic Pipe Flow at Low Reynolds Numbers in the Maximum Drag Reduction Limit.” <i>Journal of Fluid Mechanics</i>, vol. 874, Cambridge University Press, 2019, pp. 699–719, doi:<a href=\"https://doi.org/10.1017/jfm.2019.486\">10.1017/jfm.2019.486</a>.","ista":"Lopez Alonso JM, Choueiri GH, Hof B. 2019. Dynamics of viscoelastic pipe flow at low Reynolds numbers in the maximum drag reduction limit. Journal of Fluid Mechanics. 874, 699–719."},"arxiv":1,"external_id":{"isi":["000475349900001"],"arxiv":["1808.04080"]},"publisher":"Cambridge University Press","doi":"10.1017/jfm.2019.486","intvolume":"       874","isi":1,"status":"public","article_processing_charge":"No","quality_controlled":"1","type":"journal_article","publication_status":"published","author":[{"last_name":"Lopez Alonso","first_name":"Jose M","id":"40770848-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0002-0384-2022","full_name":"Lopez Alonso, Jose M"},{"full_name":"Choueiri, George H","id":"448BD5BC-F248-11E8-B48F-1D18A9856A87","first_name":"George H","last_name":"Choueiri"},{"first_name":"Björn","id":"3A374330-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0003-2057-2754","full_name":"Hof, Björn","last_name":"Hof"}]},{"tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","short":"CC BY (4.0)","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)"},"file":[{"relation":"main_file","file_size":8488733,"date_updated":"2020-07-14T12:47:53Z","date_created":"2019-12-23T07:34:56Z","access_level":"open_access","checksum":"a1b44b427ba341383197790d0e8789fa","creator":"dernst","file_name":"2019_NatureComm_Caldas.pdf","content_type":"application/pdf","file_id":"7208"}],"abstract":[{"lang":"eng","text":"During bacterial cell division, the tubulin-homolog FtsZ forms a ring-like structure at the center of the cell. This Z-ring not only organizes the division machinery, but treadmilling of FtsZ filaments was also found to play a key role in distributing proteins at the division site. What regulates the architecture, dynamics and stability of the Z-ring is currently unknown, but FtsZ-associated proteins are known to play an important role. Here, using an in vitro reconstitution approach, we studied how the well-conserved protein ZapA affects FtsZ treadmilling and filament organization into large-scale patterns. Using high-resolution fluorescence microscopy and quantitative image analysis, we found that ZapA cooperatively increases the spatial order of the filament network, but binds only transiently to FtsZ filaments and has no effect on filament length and treadmilling velocity. Together, our data provides a model for how FtsZ-associated proteins can increase the precision and stability of the bacterial cell division machinery in a switch-like manner."}],"publication_identifier":{"issn":["2041-1723"]},"language":[{"iso":"eng"}],"corr_author":"1","title":"Cooperative ordering of treadmilling filaments in cytoskeletal networks of FtsZ and its crosslinker ZapA","day":"17","scopus_import":"1","year":"2019","article_type":"original","user_id":"c635000d-4b10-11ee-a964-aac5a93f6ac1","date_published":"2019-12-17T00:00:00Z","ec_funded":1,"month":"12","ddc":["570"],"date_created":"2019-12-20T12:22:57Z","publication":"Nature Communications","date_updated":"2026-04-08T07:26:30Z","department":[{"_id":"MaLo"},{"_id":"BjHo"}],"citation":{"mla":"Dos Santos Caldas, Paulo R., et al. “Cooperative Ordering of Treadmilling Filaments in Cytoskeletal Networks of FtsZ and Its Crosslinker ZapA.” <i>Nature Communications</i>, vol. 10, 5744, Springer Nature, 2019, doi:<a href=\"https://doi.org/10.1038/s41467-019-13702-4\">10.1038/s41467-019-13702-4</a>.","ista":"Dos Santos Caldas PR, Lopez Pelegrin MD, Pearce DJG, Budanur NB, Brugués J, Loose M. 2019. Cooperative ordering of treadmilling filaments in cytoskeletal networks of FtsZ and its crosslinker ZapA. Nature Communications. 10, 5744.","ieee":"P. R. Dos Santos Caldas, M. D. Lopez Pelegrin, D. J. G. Pearce, N. B. Budanur, J. Brugués, and M. Loose, “Cooperative ordering of treadmilling filaments in cytoskeletal networks of FtsZ and its crosslinker ZapA,” <i>Nature Communications</i>, vol. 10. Springer Nature, 2019.","chicago":"Dos Santos Caldas, Paulo R, Maria D Lopez Pelegrin, Daniel J. G. Pearce, Nazmi B Budanur, Jan Brugués, and Martin Loose. “Cooperative Ordering of Treadmilling Filaments in Cytoskeletal Networks of FtsZ and Its Crosslinker ZapA.” <i>Nature Communications</i>. Springer Nature, 2019. <a href=\"https://doi.org/10.1038/s41467-019-13702-4\">https://doi.org/10.1038/s41467-019-13702-4</a>.","ama":"Dos Santos Caldas PR, Lopez Pelegrin MD, Pearce DJG, Budanur NB, Brugués J, Loose M. Cooperative ordering of treadmilling filaments in cytoskeletal networks of FtsZ and its crosslinker ZapA. <i>Nature Communications</i>. 2019;10. doi:<a href=\"https://doi.org/10.1038/s41467-019-13702-4\">10.1038/s41467-019-13702-4</a>","apa":"Dos Santos Caldas, P. R., Lopez Pelegrin, M. D., Pearce, D. J. G., Budanur, N. B., Brugués, J., &#38; Loose, M. (2019). Cooperative ordering of treadmilling filaments in cytoskeletal networks of FtsZ and its crosslinker ZapA. <i>Nature Communications</i>. Springer Nature. <a href=\"https://doi.org/10.1038/s41467-019-13702-4\">https://doi.org/10.1038/s41467-019-13702-4</a>","short":"P.R. Dos Santos Caldas, M.D. Lopez Pelegrin, D.J.G. Pearce, N.B. Budanur, J. Brugués, M. Loose, Nature Communications 10 (2019)."},"project":[{"_id":"2595697A-B435-11E9-9278-68D0E5697425","grant_number":"679239","name":"Self-Organization of the Bacterial Cell","call_identifier":"H2020"},{"_id":"260D98C8-B435-11E9-9278-68D0E5697425","name":"Reconstitution of Bacterial Cell Division Using Purified Components"}],"volume":10,"file_date_updated":"2020-07-14T12:47:53Z","oa_version":"Published Version","_id":"7197","oa":1,"publisher":"Springer Nature","external_id":{"isi":["000503009300001"]},"acknowledged_ssus":[{"_id":"LifeSc"},{"_id":"Bio"}],"has_accepted_license":"1","status":"public","isi":1,"intvolume":"        10","doi":"10.1038/s41467-019-13702-4","publication_status":"published","author":[{"id":"38FCDB4C-F248-11E8-B48F-1D18A9856A87","first_name":"Paulo R","full_name":"Dos Santos Caldas, Paulo R","orcid":"0000-0001-6730-4461","last_name":"Dos Santos Caldas"},{"last_name":"Lopez Pelegrin","full_name":"Lopez Pelegrin, Maria D","id":"319AA9CE-F248-11E8-B48F-1D18A9856A87","first_name":"Maria D"},{"last_name":"Pearce","first_name":"Daniel J. G.","full_name":"Pearce, Daniel J. G."},{"id":"3EA1010E-F248-11E8-B48F-1D18A9856A87","first_name":"Nazmi B","orcid":"0000-0003-0423-5010","full_name":"Budanur, Nazmi B","last_name":"Budanur"},{"full_name":"Brugués, Jan","first_name":"Jan","last_name":"Brugués"},{"last_name":"Loose","orcid":"0000-0001-7309-9724","full_name":"Loose, Martin","first_name":"Martin","id":"462D4284-F248-11E8-B48F-1D18A9856A87"}],"type":"journal_article","related_material":{"record":[{"status":"public","id":"8358","relation":"dissertation_contains"}]},"article_number":"5744","article_processing_charge":"No","quality_controlled":"1"},{"publication_identifier":{"eissn":["2663-337X"]},"abstract":[{"lang":"eng","text":"In many shear flows like pipe flow, plane Couette flow, plane Poiseuille flow,  etc. turbulence emerges subcritically. Here, when subjected to strong enough perturbations, the flow becomes turbulent in spite of the laminar base flow being linearly stable.  The nature of this instability has puzzled the scientific community for decades. At onset, turbulence appears in localized patches and flows are spatio-temporally intermittent.  In pipe flow the localized turbulent structures are referred to as puffs and in planar flows like plane Couette and channel flow, patches arise in the form of localized oblique bands. In this thesis, we study the onset of turbulence in channel flow in direct numerical simulations from a dynamical system theory perspective, as well as by performing experiments in a large aspect ratio channel.\r\n\r\nThe aim of the experimental work is to determine the critical Reynolds number where turbulence first becomes sustained. Recently, the onset of turbulence has been described in analogy to absorbing state phase transition (i.e. directed percolation). In particular, it has been shown that the critical point can be estimated from the competition between spreading and decay processes. Here, by performing experiments, we identify the mechanisms underlying turbulence proliferation in channel flow and find the critical Reynolds number, above which turbulence becomes sustained. Above the critical point, the continuous growth at the tip of the stripes outweighs the stochastic shedding of turbulent patches at the tail and the stripes expand. For growing stripes, the probability to decay decreases while the probability of stripe splitting increases. Consequently, and unlike for the puffs in pipe flow, neither of these two processes is time-independent i.e. memoryless. Coupling between stripe expansion and creation of new stripes via splitting leads to a significantly lower critical point ($Re_c=670+/-10$) than most earlier studies suggest.  \r\n\r\nWhile the above approach sheds light on how turbulence first becomes sustained, it provides no insight into the origin of the stripes themselves. In the numerical part of the thesis we investigate how turbulent stripes form from invariant solutions of the Navier-Stokes equations. The origin of these turbulent stripes can be identified by applying concepts from the dynamical system theory. In doing so, we identify the exact coherent structures underlying stripes and their bifurcations and how they give rise to the turbulent attractor in phase space. We first report a family of localized nonlinear traveling wave solutions of the Navier-Stokes equations in channel flow. These solutions show structural similarities with turbulent stripes in experiments like obliqueness, quasi-streamwise streaks and vortices, etc. A parametric study of these traveling wave solution is performed, with parameters like Reynolds number, stripe tilt angle and domain size, including the stability of the solutions. These solutions emerge through saddle-node bifurcations and form a phase space skeleton for the turbulent stripes observed in the experiments. The lower branches of these TW solutions at different tilt angles undergo Hopf bifurcation and new solutions branches of relative periodic orbits emerge. These RPO solutions do not belong to the same family and therefore the routes to chaos for different angles are different.  \r\n\r\nIn shear flows, turbulence at onset is transient in nature.  Consequently,turbulence can not be tracked to lower Reynolds numbers, where the dynamics may simplify. Before this happens, turbulence becomes short-lived and laminarizes. In the last part of the thesis, we show that using numerical simulations we can continue turbulent stripes in channel flow past the 'relaminarization barrier' all the way to their origin. Here, turbulent stripe dynamics simplifies and the fluctuations are no longer stochastic and the stripe settles down to a relative periodic orbit. This relative periodic orbit originates from the aforementioned traveling wave solutions. Starting from the relative periodic orbit, a small increase in speed i.e. Reynolds number gives rise to chaos and the attractor dimension sharply increases in contrast to the classical transition scenario where the instabilities affect the flow globally and give rise to much more gradual route to turbulence."}],"file":[{"file_size":45828099,"relation":"source_file","date_updated":"2020-07-14T12:47:46Z","date_created":"2019-10-23T09:54:43Z","access_level":"closed","file_name":"Chaitanya_Paranjape_source_files_tex_figures.zip","checksum":"7ba298ba0ce7e1d11691af6b8eaf0a0a","creator":"cparanjape","content_type":"application/zip","file_id":"6962"},{"file_size":19504197,"relation":"main_file","date_updated":"2020-07-14T12:47:46Z","access_level":"open_access","date_created":"2019-10-23T10:37:09Z","file_name":"Chaitanya_Paranjape_Thesis.pdf","checksum":"642697618314e31ac31392da7909c2d9","creator":"cparanjape","content_type":"application/pdf","file_id":"6963"}],"corr_author":"1","language":[{"iso":"eng"}],"alternative_title":["ISTA Thesis"],"degree_awarded":"PhD","keyword":["Instabilities","Turbulence","Nonlinear dynamics"],"month":"10","date_published":"2019-10-24T00:00:00Z","date_updated":"2026-04-08T07:46:58Z","date_created":"2019-10-22T12:08:43Z","page":"138","ddc":["532"],"day":"24","title":"Onset of turbulence in plane Poiseuille flow","user_id":"ba8df636-2132-11f1-aed0-ed93e2281fdd","year":"2019","publisher":"Institute of Science and Technology Austria","citation":{"chicago":"Paranjape, Chaitanya S. “Onset of Turbulence in Plane Poiseuille Flow.” Institute of Science and Technology Austria, 2019. <a href=\"https://doi.org/10.15479/AT:ISTA:6957\">https://doi.org/10.15479/AT:ISTA:6957</a>.","ama":"Paranjape CS. Onset of turbulence in plane Poiseuille flow. 2019. doi:<a href=\"https://doi.org/10.15479/AT:ISTA:6957\">10.15479/AT:ISTA:6957</a>","apa":"Paranjape, C. S. (2019). <i>Onset of turbulence in plane Poiseuille flow</i>. Institute of Science and Technology Austria. <a href=\"https://doi.org/10.15479/AT:ISTA:6957\">https://doi.org/10.15479/AT:ISTA:6957</a>","short":"C.S. Paranjape, Onset of Turbulence in Plane Poiseuille Flow, Institute of Science and Technology Austria, 2019.","ista":"Paranjape CS. 2019. Onset of turbulence in plane Poiseuille flow. Institute of Science and Technology Austria.","mla":"Paranjape, Chaitanya S. <i>Onset of Turbulence in Plane Poiseuille Flow</i>. Institute of Science and Technology Austria, 2019, doi:<a href=\"https://doi.org/10.15479/AT:ISTA:6957\">10.15479/AT:ISTA:6957</a>.","ieee":"C. S. Paranjape, “Onset of turbulence in plane Poiseuille flow,” Institute of Science and Technology Austria, 2019."},"department":[{"_id":"BjHo"}],"oa_version":"Published Version","_id":"6957","oa":1,"file_date_updated":"2020-07-14T12:47:46Z","type":"dissertation","publication_status":"published","author":[{"full_name":"Paranjape, Chaitanya S","first_name":"Chaitanya S","id":"3D85B7C4-F248-11E8-B48F-1D18A9856A87","last_name":"Paranjape"}],"article_processing_charge":"No","OA_place":"publisher","supervisor":[{"orcid":"0000-0003-2057-2754","full_name":"Hof, Björn","id":"3A374330-F248-11E8-B48F-1D18A9856A87","first_name":"Björn","last_name":"Hof"}],"has_accepted_license":"1","status":"public","doi":"10.15479/AT:ISTA:6957"},{"quality_controlled":"1","article_processing_charge":"No","type":"journal_article","publication_status":"published","author":[{"first_name":"Baofang","full_name":"Song, Baofang","last_name":"Song"},{"last_name":"Plana","full_name":"Plana, Carlos","first_name":"Carlos"},{"orcid":"0000-0002-0384-2022","full_name":"Lopez Alonso, Jose M","first_name":"Jose M","id":"40770848-F248-11E8-B48F-1D18A9856A87","last_name":"Lopez Alonso"},{"last_name":"Avila","first_name":"Marc","full_name":"Avila, Marc"}],"intvolume":"       117","doi":"10.1016/j.ijmultiphaseflow.2019.04.027","isi":1,"status":"public","arxiv":1,"publisher":"Elsevier","external_id":{"isi":["000474496000002"],"arxiv":["1902.07351"]},"_id":"6413","oa_version":"Preprint","oa":1,"volume":117,"citation":{"apa":"Song, B., Plana, C., Lopez Alonso, J. M., &#38; Avila, M. (2019). Phase-field simulation of core-annular pipe flow. <i>International Journal of Multiphase Flow</i>. Elsevier. <a href=\"https://doi.org/10.1016/j.ijmultiphaseflow.2019.04.027\">https://doi.org/10.1016/j.ijmultiphaseflow.2019.04.027</a>","ama":"Song B, Plana C, Lopez Alonso JM, Avila M. Phase-field simulation of core-annular pipe flow. <i>International Journal of Multiphase Flow</i>. 2019;117:14-24. doi:<a href=\"https://doi.org/10.1016/j.ijmultiphaseflow.2019.04.027\">10.1016/j.ijmultiphaseflow.2019.04.027</a>","short":"B. Song, C. Plana, J.M. Lopez Alonso, M. Avila, International Journal of Multiphase Flow 117 (2019) 14–24.","chicago":"Song, Baofang, Carlos Plana, Jose M Lopez Alonso, and Marc Avila. “Phase-Field Simulation of Core-Annular Pipe Flow.” <i>International Journal of Multiphase Flow</i>. Elsevier, 2019. <a href=\"https://doi.org/10.1016/j.ijmultiphaseflow.2019.04.027\">https://doi.org/10.1016/j.ijmultiphaseflow.2019.04.027</a>.","ieee":"B. Song, C. Plana, J. M. Lopez Alonso, and M. Avila, “Phase-field simulation of core-annular pipe flow,” <i>International Journal of Multiphase Flow</i>, vol. 117. Elsevier, pp. 14–24, 2019.","ista":"Song B, Plana C, Lopez Alonso JM, Avila M. 2019. Phase-field simulation of core-annular pipe flow. International Journal of Multiphase Flow. 117, 14–24.","mla":"Song, Baofang, et al. “Phase-Field Simulation of Core-Annular Pipe Flow.” <i>International Journal of Multiphase Flow</i>, vol. 117, Elsevier, 2019, pp. 14–24, doi:<a href=\"https://doi.org/10.1016/j.ijmultiphaseflow.2019.04.027\">10.1016/j.ijmultiphaseflow.2019.04.027</a>."},"department":[{"_id":"BjHo"}],"date_created":"2019-05-13T07:58:35Z","publication":"International Journal of Multiphase Flow","date_updated":"2026-04-16T09:49:27Z","page":"14-24","month":"08","date_published":"2019-08-01T00:00:00Z","user_id":"ba8df636-2132-11f1-aed0-ed93e2281fdd","article_type":"original","year":"2019","scopus_import":"1","day":"01","title":"Phase-field simulation of core-annular pipe flow","language":[{"iso":"eng"}],"publication_identifier":{"issn":["0301-9322"]},"abstract":[{"text":"Phase-field methods have long been used to model the flow of immiscible fluids. Their ability to naturally capture interface topological changes is widely recognized, but their accuracy in simulating flows of real fluids in practical geometries is not established. We here quantitatively investigate the convergence of the phase-field method to the sharp-interface limit with simulations of two-phase pipe flow. We focus on core-annular flows, in which a highly viscous fluid is lubricated by a less viscous fluid, and validate our simulations with an analytic laminar solution, a formal linear stability analysis and also in the fully nonlinear regime. We demonstrate the ability of the phase-field method to accurately deal with non-rectangular geometry, strong advection, unsteady fluctuations and large viscosity contrast. We argue that phase-field methods are very promising for quantitatively studying moderately turbulent flows, especially at high concentrations of the disperse phase.","lang":"eng"}],"main_file_link":[{"url":"https://arxiv.org/abs/1902.07351","open_access":"1"}]},{"main_file_link":[{"open_access":"1","url":"https://doi.org/10.1016/j.cell.2019.04.030"}],"file":[{"access_level":"open_access","date_created":"2020-10-21T07:22:34Z","date_updated":"2020-10-21T07:22:34Z","file_size":3356292,"relation":"main_file","success":1,"file_id":"8686","content_type":"application/pdf","creator":"dernst","checksum":"aea43726d80e35ce3885073a5f05c3e3","file_name":"2019_Cell_Shamipour_accepted.pdf"}],"publication_identifier":{"issn":["0092-8674"],"eissn":["1097-4172"]},"abstract":[{"text":"Segregation of maternal determinants within the oocyte constitutes the first step in embryo patterning. In zebrafish oocytes, extensive ooplasmic streaming leads to the segregation of ooplasm from yolk granules along the animal-vegetal axis of the oocyte. Here, we show that this process does not rely on cortical actin reorganization, as previously thought, but instead on a cell-cycle-dependent bulk actin polymerization wave traveling from the animal to the vegetal pole of the oocyte. This wave functions in segregation by both pulling ooplasm animally and pushing yolk granules vegetally. Using biophysical experimentation and theory, we show that ooplasm pulling is mediated by bulk actin network flows exerting friction forces on the ooplasm, while yolk granule pushing is achieved by a mechanism closely resembling actin comet formation on yolk granules. Our study defines a novel role of cell-cycle-controlled bulk actin polymerization waves in oocyte polarization via ooplasmic segregation.","lang":"eng"}],"language":[{"iso":"eng"}],"date_published":"2019-05-30T00:00:00Z","month":"05","ec_funded":1,"page":"1463-1479.e18","ddc":["570"],"publication":"Cell","date_updated":"2026-06-07T22:30:09Z","date_created":"2019-06-02T21:59:12Z","title":"Bulk actin dynamics drive phase segregation in zebrafish oocytes","day":"30","year":"2019","article_type":"original","scopus_import":"1","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","external_id":{"pmid":["31080065"],"isi":["000469415100013"]},"publisher":"Elsevier","acknowledged_ssus":[{"_id":"Bio"},{"_id":"PreCl"}],"project":[{"_id":"260F1432-B435-11E9-9278-68D0E5697425","grant_number":"742573","call_identifier":"H2020","name":"Interaction and feedback between cell mechanics and fate specification in vertebrate gastrulation"},{"_id":"268294B6-B435-11E9-9278-68D0E5697425","grant_number":"P31639","call_identifier":"FWF","name":"Active mechano-chemical description of the cell cytoskeleton"}],"department":[{"_id":"CaHe"},{"_id":"EdHa"},{"_id":"BjHo"}],"citation":{"ama":"Shamipour S, Kardos R, Xue S, Hof B, Hannezo EB, Heisenberg C-PJ. Bulk actin dynamics drive phase segregation in zebrafish oocytes. <i>Cell</i>. 2019;177(6):1463-1479.e18. doi:<a href=\"https://doi.org/10.1016/j.cell.2019.04.030\">10.1016/j.cell.2019.04.030</a>","short":"S. Shamipour, R. Kardos, S. Xue, B. Hof, E.B. Hannezo, C.-P.J. Heisenberg, Cell 177 (2019) 1463–1479.e18.","apa":"Shamipour, S., Kardos, R., Xue, S., Hof, B., Hannezo, E. B., &#38; Heisenberg, C.-P. J. (2019). Bulk actin dynamics drive phase segregation in zebrafish oocytes. <i>Cell</i>. Elsevier. <a href=\"https://doi.org/10.1016/j.cell.2019.04.030\">https://doi.org/10.1016/j.cell.2019.04.030</a>","chicago":"Shamipour, Shayan, Roland Kardos, Shi-lei Xue, Björn Hof, Edouard B Hannezo, and Carl-Philipp J Heisenberg. “Bulk Actin Dynamics Drive Phase Segregation in Zebrafish Oocytes.” <i>Cell</i>. Elsevier, 2019. <a href=\"https://doi.org/10.1016/j.cell.2019.04.030\">https://doi.org/10.1016/j.cell.2019.04.030</a>.","ieee":"S. Shamipour, R. Kardos, S. Xue, B. Hof, E. B. Hannezo, and C.-P. J. Heisenberg, “Bulk actin dynamics drive phase segregation in zebrafish oocytes,” <i>Cell</i>, vol. 177, no. 6. Elsevier, p. 1463–1479.e18, 2019.","mla":"Shamipour, Shayan, et al. “Bulk Actin Dynamics Drive Phase Segregation in Zebrafish Oocytes.” <i>Cell</i>, vol. 177, no. 6, Elsevier, 2019, p. 1463–1479.e18, doi:<a href=\"https://doi.org/10.1016/j.cell.2019.04.030\">10.1016/j.cell.2019.04.030</a>.","ista":"Shamipour S, Kardos R, Xue S, Hof B, Hannezo EB, Heisenberg C-PJ. 2019. Bulk actin dynamics drive phase segregation in zebrafish oocytes. Cell. 177(6), 1463–1479.e18."},"file_date_updated":"2020-10-21T07:22:34Z","volume":177,"_id":"6508","oa":1,"oa_version":"Published Version","publication_status":"published","author":[{"last_name":"Shamipour","full_name":"Shamipour, Shayan","id":"40B34FE2-F248-11E8-B48F-1D18A9856A87","first_name":"Shayan"},{"full_name":"Kardos, Roland","first_name":"Roland","id":"4039350E-F248-11E8-B48F-1D18A9856A87","last_name":"Kardos"},{"first_name":"Shi-lei","id":"31D2C804-F248-11E8-B48F-1D18A9856A87","full_name":"Xue, Shi-lei","last_name":"Xue"},{"last_name":"Hof","first_name":"Björn","id":"3A374330-F248-11E8-B48F-1D18A9856A87","full_name":"Hof, Björn","orcid":"0000-0003-2057-2754"},{"first_name":"Edouard B","id":"3A9DB764-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0001-6005-1561","full_name":"Hannezo, Edouard B","last_name":"Hannezo"},{"id":"39427864-F248-11E8-B48F-1D18A9856A87","first_name":"Carl-Philipp J","full_name":"Heisenberg, Carl-Philipp J","orcid":"0000-0002-0912-4566","last_name":"Heisenberg"}],"type":"journal_article","related_material":{"record":[{"id":"8350","status":"public","relation":"dissertation_contains"}],"link":[{"url":"https://ist.ac.at/en/news/how-the-cytoplasm-separates-from-the-yolk/","relation":"press_release","description":"News on IST Homepage"}]},"pmid":1,"article_processing_charge":"No","quality_controlled":"1","acknowledgement":"We would like to thank Pierre Recho, Guillaume Salbreux, and Silvia Grigolon for advice on the theory, Lila Solnica-Krezel for kindly providing us with zebrafish dachsous mutants, members of the Heisenberg and Hannezo groups for fruitful discussions, and the Bioimaging and zebrafish facilities at IST Austria for their continuous support. This project has received funding from the European Union (European Research Council Advanced Grant 742573 to C.P.H.) and from the Austrian Science Fund (FWF) (P 31639 to E.H.).","issue":"6","status":"public","has_accepted_license":"1","isi":1,"doi":"10.1016/j.cell.2019.04.030","intvolume":"       177"},{"title":"Mechanosensation of tight junctions depends on ZO-1 phase separation and flow","day":"31","article_type":"original","scopus_import":"1","year":"2019","user_id":"4359f0d1-fa6c-11eb-b949-802e58b17ae8","date_published":"2019-10-31T00:00:00Z","month":"10","ec_funded":1,"page":"937-952.e18","ddc":["570"],"date_updated":"2026-06-07T22:30:09Z","publication":"Cell","date_created":"2019-11-12T12:51:06Z","file":[{"file_id":"8684","success":1,"content_type":"application/pdf","file_name":"2019_Cell_Schwayer_accepted.pdf","creator":"dernst","checksum":"33dac4bb77ee630e2666e936b4d57980","date_created":"2020-10-21T07:09:45Z","access_level":"open_access","file_size":8805878,"date_updated":"2020-10-21T07:09:45Z","relation":"main_file"}],"publication_identifier":{"issn":["0092-8674"],"eissn":["1097-4172"]},"language":[{"iso":"eng"}],"has_accepted_license":"1","status":"public","issue":"4","isi":1,"doi":"10.1016/j.cell.2019.10.006","intvolume":"       179","author":[{"orcid":"0000-0001-5130-2226","full_name":"Schwayer, Cornelia","first_name":"Cornelia","id":"3436488C-F248-11E8-B48F-1D18A9856A87","last_name":"Schwayer"},{"first_name":"Shayan","id":"40B34FE2-F248-11E8-B48F-1D18A9856A87","full_name":"Shamipour, Shayan","last_name":"Shamipour"},{"last_name":"Pranjic-Ferscha","first_name":"Kornelija","id":"4362B3C2-F248-11E8-B48F-1D18A9856A87","full_name":"Pranjic-Ferscha, Kornelija"},{"last_name":"Schauer","first_name":"Alexandra","id":"30A536BA-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0001-7659-9142","full_name":"Schauer, Alexandra"},{"last_name":"Balda","first_name":"M","full_name":"Balda, M"},{"last_name":"Tada","full_name":"Tada, M","first_name":"M"},{"first_name":"K","full_name":"Matter, K","last_name":"Matter"},{"last_name":"Heisenberg","id":"39427864-F248-11E8-B48F-1D18A9856A87","first_name":"Carl-Philipp J","full_name":"Heisenberg, Carl-Philipp J","orcid":"0000-0002-0912-4566"}],"publication_status":"published","type":"journal_article","related_material":{"link":[{"relation":"press_release","url":"https://ist.ac.at/en/news/biochemistry-meets-mechanics-the-sensitive-nature-of-cell-cell-contact-formation-in-embryo-development/","description":"News auf IST Website"}],"record":[{"relation":"dissertation_contains","status":"public","id":"7186"},{"relation":"dissertation_contains","status":"public","id":"8350"}]},"pmid":1,"article_processing_charge":"No","quality_controlled":"1","project":[{"call_identifier":"H2020","name":"Interaction and feedback between cell mechanics and fate specification in vertebrate gastrulation","_id":"260F1432-B435-11E9-9278-68D0E5697425","grant_number":"742573"}],"citation":{"chicago":"Schwayer, Cornelia, Shayan Shamipour, Kornelija Pranjic-Ferscha, Alexandra Schauer, M Balda, M Tada, K Matter, and Carl-Philipp J Heisenberg. “Mechanosensation of Tight Junctions Depends on ZO-1 Phase Separation and Flow.” <i>Cell</i>. Cell Press, 2019. <a href=\"https://doi.org/10.1016/j.cell.2019.10.006\">https://doi.org/10.1016/j.cell.2019.10.006</a>.","short":"C. Schwayer, S. Shamipour, K. Pranjic-Ferscha, A. Schauer, M. Balda, M. Tada, K. Matter, C.-P.J. Heisenberg, Cell 179 (2019) 937–952.e18.","ama":"Schwayer C, Shamipour S, Pranjic-Ferscha K, et al. Mechanosensation of tight junctions depends on ZO-1 phase separation and flow. <i>Cell</i>. 2019;179(4):937-952.e18. doi:<a href=\"https://doi.org/10.1016/j.cell.2019.10.006\">10.1016/j.cell.2019.10.006</a>","apa":"Schwayer, C., Shamipour, S., Pranjic-Ferscha, K., Schauer, A., Balda, M., Tada, M., … Heisenberg, C.-P. J. (2019). Mechanosensation of tight junctions depends on ZO-1 phase separation and flow. <i>Cell</i>. Cell Press. <a href=\"https://doi.org/10.1016/j.cell.2019.10.006\">https://doi.org/10.1016/j.cell.2019.10.006</a>","ista":"Schwayer C, Shamipour S, Pranjic-Ferscha K, Schauer A, Balda M, Tada M, Matter K, Heisenberg C-PJ. 2019. Mechanosensation of tight junctions depends on ZO-1 phase separation and flow. Cell. 179(4), 937–952.e18.","mla":"Schwayer, Cornelia, et al. “Mechanosensation of Tight Junctions Depends on ZO-1 Phase Separation and Flow.” <i>Cell</i>, vol. 179, no. 4, Cell Press, 2019, p. 937–952.e18, doi:<a href=\"https://doi.org/10.1016/j.cell.2019.10.006\">10.1016/j.cell.2019.10.006</a>.","ieee":"C. Schwayer <i>et al.</i>, “Mechanosensation of tight junctions depends on ZO-1 phase separation and flow,” <i>Cell</i>, vol. 179, no. 4. Cell Press, p. 937–952.e18, 2019."},"department":[{"_id":"CaHe"},{"_id":"BjHo"}],"volume":179,"file_date_updated":"2020-10-21T07:09:45Z","oa":1,"_id":"7001","oa_version":"Submitted Version","external_id":{"pmid":["31675500"],"isi":["000493898000012"]},"publisher":"Cell Press","acknowledged_ssus":[{"_id":"PreCl"},{"_id":"Bio"}]},{"main_file_link":[{"open_access":"1","url":"https://arxiv.org/abs/1809.07625"}],"publication_identifier":{"issn":["0098-2202"],"eissn":["1528-901X"]},"abstract":[{"lang":"eng","text":"Based on a novel control scheme, where a steady modification of the streamwise velocity profile leads to complete relaminarization of initially fully turbulent pipe flow, we investigate the applicability and usefulness of custom-shaped honeycombs for such control. The custom-shaped honeycombs are used as stationary flow management devices which generate specific modifications of the streamwise velocity profile. Stereoscopic particle image velocimetry and pressure drop measurements are used to investigate and capture the development of the relaminarizing flow downstream these devices. We compare the performance of straight (constant length across the radius of the pipe) honeycombs with custom-shaped ones (variable length across the radius) and try to determine the optimal shape for maximal relaminarization at minimal pressure loss. The optimally modified streamwise velocity profile is found to be M-shaped, and the maximum attainable Reynolds number for total relaminarization is found to be of the order of 10,000. Consequently, the respective reduction in skin friction downstream of the device is almost by a factor of 5. The break-even point, where the additional pressure drop caused by the device is balanced by the savings due to relaminarization and a net gain is obtained, corresponds to a downstream stretch of distances as low as approximately 100 pipe diameters of laminar flow."}],"language":[{"iso":"eng"}],"title":"Relaminarization of pipe flow by means of 3D-printed shaped honeycombs","day":"01","scopus_import":"1","year":"2019","article_type":"original","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","date_published":"2019-11-01T00:00:00Z","ec_funded":1,"month":"11","date_created":"2019-05-26T21:59:13Z","publication":"Journal of Fluids Engineering","date_updated":"2026-06-07T22:30:46Z","department":[{"_id":"BjHo"}],"citation":{"short":"J. Kühnen, D. Scarselli, B. Hof, Journal of Fluids Engineering 141 (2019).","ama":"Kühnen J, Scarselli D, Hof B. Relaminarization of pipe flow by means of 3D-printed shaped honeycombs. <i>Journal of Fluids Engineering</i>. 2019;141(11). doi:<a href=\"https://doi.org/10.1115/1.4043494\">10.1115/1.4043494</a>","apa":"Kühnen, J., Scarselli, D., &#38; Hof, B. (2019). Relaminarization of pipe flow by means of 3D-printed shaped honeycombs. <i>Journal of Fluids Engineering</i>. ASME. <a href=\"https://doi.org/10.1115/1.4043494\">https://doi.org/10.1115/1.4043494</a>","chicago":"Kühnen, Jakob, Davide Scarselli, and Björn Hof. “Relaminarization of Pipe Flow by Means of 3D-Printed Shaped Honeycombs.” <i>Journal of Fluids Engineering</i>. ASME, 2019. <a href=\"https://doi.org/10.1115/1.4043494\">https://doi.org/10.1115/1.4043494</a>.","ieee":"J. Kühnen, D. Scarselli, and B. Hof, “Relaminarization of pipe flow by means of 3D-printed shaped honeycombs,” <i>Journal of Fluids Engineering</i>, vol. 141, no. 11. ASME, 2019.","ista":"Kühnen J, Scarselli D, Hof B. 2019. Relaminarization of pipe flow by means of 3D-printed shaped honeycombs. Journal of Fluids Engineering. 141(11), 111105.","mla":"Kühnen, Jakob, et al. “Relaminarization of Pipe Flow by Means of 3D-Printed Shaped Honeycombs.” <i>Journal of Fluids Engineering</i>, vol. 141, no. 11, 111105, ASME, 2019, doi:<a href=\"https://doi.org/10.1115/1.4043494\">10.1115/1.4043494</a>."},"project":[{"call_identifier":"FP7","name":"Decoding the complexity of turbulence at its origin","_id":"25152F3A-B435-11E9-9278-68D0E5697425","grant_number":"306589"}],"volume":141,"oa":1,"_id":"6486","oa_version":"Preprint","publisher":"ASME","external_id":{"isi":["000487748600005"],"arxiv":["1809.07625"]},"acknowledged_ssus":[{"_id":"M-Shop"}],"arxiv":1,"issue":"11","status":"public","isi":1,"intvolume":"       141","doi":"10.1115/1.4043494","author":[{"last_name":"Kühnen","orcid":"0000-0003-4312-0179","full_name":"Kühnen, Jakob","first_name":"Jakob","id":"3A47AE32-F248-11E8-B48F-1D18A9856A87"},{"last_name":"Scarselli","full_name":"Scarselli, Davide","orcid":"0000-0001-5227-4271","id":"40315C30-F248-11E8-B48F-1D18A9856A87","first_name":"Davide"},{"last_name":"Hof","orcid":"0000-0003-2057-2754","full_name":"Hof, Björn","id":"3A374330-F248-11E8-B48F-1D18A9856A87","first_name":"Björn"}],"publication_status":"published","type":"journal_article","related_material":{"record":[{"id":"7258","status":"public","relation":"dissertation_contains"}]},"article_number":"111105","quality_controlled":"1","article_processing_charge":"No"},{"volume":867,"_id":"6228","oa":1,"oa_version":"Preprint","project":[{"_id":"25152F3A-B435-11E9-9278-68D0E5697425","grant_number":"306589","name":"Decoding the complexity of turbulence at its origin","call_identifier":"FP7"},{"grant_number":"737549","_id":"25104D44-B435-11E9-9278-68D0E5697425","name":"Eliminating turbulence in oil pipelines","call_identifier":"H2020"}],"citation":{"chicago":"Scarselli, Davide, Jakob Kühnen, and Björn Hof. “Relaminarising Pipe Flow by Wall Movement.” <i>Journal of Fluid Mechanics</i>. Cambridge University Press, 2019. <a href=\"https://doi.org/10.1017/jfm.2019.191\">https://doi.org/10.1017/jfm.2019.191</a>.","apa":"Scarselli, D., Kühnen, J., &#38; Hof, B. (2019). Relaminarising pipe flow by wall movement. <i>Journal of Fluid Mechanics</i>. Cambridge University Press. <a href=\"https://doi.org/10.1017/jfm.2019.191\">https://doi.org/10.1017/jfm.2019.191</a>","ama":"Scarselli D, Kühnen J, Hof B. Relaminarising pipe flow by wall movement. <i>Journal of Fluid Mechanics</i>. 2019;867:934-948. doi:<a href=\"https://doi.org/10.1017/jfm.2019.191\">10.1017/jfm.2019.191</a>","short":"D. Scarselli, J. Kühnen, B. Hof, Journal of Fluid Mechanics 867 (2019) 934–948.","mla":"Scarselli, Davide, et al. “Relaminarising Pipe Flow by Wall Movement.” <i>Journal of Fluid Mechanics</i>, vol. 867, Cambridge University Press, 2019, pp. 934–48, doi:<a href=\"https://doi.org/10.1017/jfm.2019.191\">10.1017/jfm.2019.191</a>.","ista":"Scarselli D, Kühnen J, Hof B. 2019. Relaminarising pipe flow by wall movement. Journal of Fluid Mechanics. 867, 934–948.","ieee":"D. Scarselli, J. Kühnen, and B. Hof, “Relaminarising pipe flow by wall movement,” <i>Journal of Fluid Mechanics</i>, vol. 867. Cambridge University Press, pp. 934–948, 2019."},"department":[{"_id":"BjHo"}],"arxiv":1,"external_id":{"arxiv":["1807.05357"],"isi":["000462606100001"]},"publisher":"Cambridge University Press","isi":1,"doi":"10.1017/jfm.2019.191","intvolume":"       867","status":"public","related_material":{"link":[{"relation":"supplementary_material","url":"https://doi.org/10.1017/jfm.2019.191"}],"record":[{"relation":"dissertation_contains","id":"7258","status":"public"}]},"quality_controlled":"1","article_processing_charge":"No","author":[{"last_name":"Scarselli","id":"40315C30-F248-11E8-B48F-1D18A9856A87","first_name":"Davide","orcid":"0000-0001-5227-4271","full_name":"Scarselli, Davide"},{"last_name":"Kühnen","orcid":"0000-0003-4312-0179","full_name":"Kühnen, Jakob","id":"3A47AE32-F248-11E8-B48F-1D18A9856A87","first_name":"Jakob"},{"last_name":"Hof","first_name":"Björn","id":"3A374330-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0003-2057-2754","full_name":"Hof, Björn"}],"publication_status":"published","type":"journal_article","language":[{"iso":"eng"}],"main_file_link":[{"url":"https://arxiv.org/abs/1807.05357","open_access":"1"}],"publication_identifier":{"eissn":["1469-7645"],"issn":["0022-1120"]},"abstract":[{"text":"Following  the  recent  observation  that  turbulent  pipe  flow  can  be  relaminarised  bya  relatively  simple  modification  of  the  mean  velocity  profile,  we  here  carry  out  aquantitative  experimental  investigation  of  this  phenomenon.  Our  study  confirms  thata  flat  velocity  profile  leads  to  a  collapse  of  turbulence  and  in  order  to  achieve  theblunted  profile  shape,  we  employ  a  moving  pipe  segment  that  is  briefly  and  rapidlyshifted  in  the  streamwise  direction.  The  relaminarisation  threshold  and  the  minimumshift  length  and  speeds  are  determined  as  a  function  of  Reynolds  number.  Althoughturbulence  is  still  active  after  the  acceleration  phase,  the  modulated  profile  possessesa  severely  decreased  lift-up  potential  as  measured  by  transient  growth.  As  shown,this  results  in  an  exponential  decay  of  fluctuations  and  the  flow  relaminarises.  Whilethis  method  can  be  easily  applied  at  low  to  moderate  flow  speeds,  the  minimumstreamwise  length  over  which  the  acceleration  needs  to  act  increases  linearly  with  theReynolds  number.","lang":"eng"}],"year":"2019","scopus_import":"1","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","title":"Relaminarising pipe flow by wall movement","day":"25","page":"934-948","publication":"Journal of Fluid Mechanics","date_updated":"2026-06-07T22:30:46Z","date_created":"2019-04-07T21:59:14Z","date_published":"2019-05-25T00:00:00Z","month":"05","ec_funded":1},{"language":[{"iso":"eng"}],"publication_identifier":{"issn":["0031-9007"],"eissn":["1079-7114"]},"abstract":[{"lang":"eng","text":"Suspended particles can alter the properties of fluids and in particular also affect the transition fromlaminar to turbulent flow. An earlier study [Mataset al.,Phys. Rev. Lett.90, 014501 (2003)] reported howthe subcritical (i.e., hysteretic) transition to turbulent puffs is affected by the addition of particles. Here weshow that in addition to this known transition, with increasing concentration a supercritical (i.e.,continuous) transition to a globally fluctuating state is found. At the same time the Newtonian-typetransition to puffs is delayed to larger Reynolds numbers. At even higher concentration only the globallyfluctuating state is found. The dynamics of particle laden flows are hence determined by two competinginstabilities that give rise to three flow regimes: Newtonian-type turbulence at low, a particle inducedglobally fluctuating state at high, and a coexistence state at intermediate concentrations."}],"main_file_link":[{"open_access":"1","url":"https://arxiv.org/abs/1809.06358"}],"user_id":"ba8df636-2132-11f1-aed0-ed93e2281fdd","year":"2019","scopus_import":"1","day":"22","title":"Transition to turbulence in particle laden flows","publication":"Physical Review Letters","date_updated":"2026-06-07T22:31:01Z","date_created":"2019-03-31T21:59:12Z","month":"03","date_published":"2019-03-22T00:00:00Z","_id":"6189","oa_version":"Preprint","oa":1,"volume":122,"citation":{"apa":"Agrawal, N., Choueiri, G. H., &#38; Hof, B. (2019). Transition to turbulence in particle laden flows. <i>Physical Review Letters</i>. American Physical Society. <a href=\"https://doi.org/10.1103/PhysRevLett.122.114502\">https://doi.org/10.1103/PhysRevLett.122.114502</a>","ama":"Agrawal N, Choueiri GH, Hof B. Transition to turbulence in particle laden flows. <i>Physical Review Letters</i>. 2019;122(11). doi:<a href=\"https://doi.org/10.1103/PhysRevLett.122.114502\">10.1103/PhysRevLett.122.114502</a>","short":"N. Agrawal, G.H. Choueiri, B. Hof, Physical Review Letters 122 (2019).","chicago":"Agrawal, Nishchal, George H Choueiri, and Björn Hof. “Transition to Turbulence in Particle Laden Flows.” <i>Physical Review Letters</i>. American Physical Society, 2019. <a href=\"https://doi.org/10.1103/PhysRevLett.122.114502\">https://doi.org/10.1103/PhysRevLett.122.114502</a>.","ieee":"N. Agrawal, G. H. Choueiri, and B. Hof, “Transition to turbulence in particle laden flows,” <i>Physical Review Letters</i>, vol. 122, no. 11. American Physical Society, 2019.","mla":"Agrawal, Nishchal, et al. “Transition to Turbulence in Particle Laden Flows.” <i>Physical Review Letters</i>, vol. 122, no. 11, 114502, American Physical Society, 2019, doi:<a href=\"https://doi.org/10.1103/PhysRevLett.122.114502\">10.1103/PhysRevLett.122.114502</a>.","ista":"Agrawal N, Choueiri GH, Hof B. 2019. Transition to turbulence in particle laden flows. Physical Review Letters. 122(11), 114502."},"department":[{"_id":"BjHo"}],"arxiv":1,"external_id":{"arxiv":["1809.06358"],"isi":["000461922000006"],"pmid":["30951357"]},"publisher":"American Physical Society","doi":"10.1103/PhysRevLett.122.114502","intvolume":"       122","isi":1,"status":"public","issue":"11","pmid":1,"quality_controlled":"1","article_processing_charge":"No","article_number":"114502","related_material":{"record":[{"id":"9728","status":"public","relation":"dissertation_contains"}]},"type":"journal_article","publication_status":"published","author":[{"first_name":"Nishchal","id":"469E6004-F248-11E8-B48F-1D18A9856A87","full_name":"Agrawal, Nishchal","last_name":"Agrawal"},{"first_name":"George H","id":"448BD5BC-F248-11E8-B48F-1D18A9856A87","full_name":"Choueiri, George H","last_name":"Choueiri"},{"last_name":"Hof","id":"3A374330-F248-11E8-B48F-1D18A9856A87","first_name":"Björn","full_name":"Hof, Björn","orcid":"0000-0003-2057-2754"}]},{"language":[{"iso":"eng"}],"abstract":[{"lang":"eng","text":"Over the past decade, the edge of chaos has proven to be a fruitful starting point for investigations of shear flows when the laminar base flow is linearly stable. Numerous computational studies of shear flows demonstrated the existence of states that separate laminar and turbulent regions of the state space. In addition, some studies determined invariant solutions that reside on this edge. In this paper, we study the unstable manifold of one such solution with the aid of continuous symmetry reduction, which we formulate here for the simultaneous quotiening of axial and azimuthal symmetries. Upon our investigation of the unstable manifold, we discover a previously unknown traveling-wave solution on the laminar-turbulent boundary with a relatively complex structure. By means of low-dimensional projections, we visualize different dynamical paths that connect these solutions to the turbulence. Our numerical experiments demonstrate that the laminar-turbulent boundary exhibits qualitatively different regions whose properties are influenced by the nearby invariant solutions."}],"main_file_link":[{"url":"https://arxiv.org/abs/1802.01918","open_access":"1"}],"user_id":"c635000d-4b10-11ee-a964-aac5a93f6ac1","year":"2018","scopus_import":"1","day":"30","title":"Complexity of the laminar-turbulent boundary in pipe flow","publication":"Physical Review Fluids","date_updated":"2023-09-11T12:45:44Z","date_created":"2018-12-11T11:45:39Z","month":"05","date_published":"2018-05-30T00:00:00Z","_id":"291","oa_version":"Preprint","oa":1,"publist_id":"7590","volume":3,"department":[{"_id":"BjHo"}],"citation":{"ista":"Budanur NB, Hof B. 2018. Complexity of the laminar-turbulent boundary in pipe flow. Physical Review Fluids. 3(5), 054401.","mla":"Budanur, Nazmi B., and Björn Hof. “Complexity of the Laminar-Turbulent Boundary in Pipe Flow.” <i>Physical Review Fluids</i>, vol. 3, no. 5, 054401, American Physical Society, 2018, doi:<a href=\"https://doi.org/10.1103/PhysRevFluids.3.054401\">10.1103/PhysRevFluids.3.054401</a>.","ieee":"N. B. Budanur and B. Hof, “Complexity of the laminar-turbulent boundary in pipe flow,” <i>Physical Review Fluids</i>, vol. 3, no. 5. American Physical Society, 2018.","chicago":"Budanur, Nazmi B, and Björn Hof. “Complexity of the Laminar-Turbulent Boundary in Pipe Flow.” <i>Physical Review Fluids</i>. American Physical Society, 2018. <a href=\"https://doi.org/10.1103/PhysRevFluids.3.054401\">https://doi.org/10.1103/PhysRevFluids.3.054401</a>.","apa":"Budanur, N. B., &#38; Hof, B. (2018). Complexity of the laminar-turbulent boundary in pipe flow. <i>Physical Review Fluids</i>. American Physical Society. <a href=\"https://doi.org/10.1103/PhysRevFluids.3.054401\">https://doi.org/10.1103/PhysRevFluids.3.054401</a>","ama":"Budanur NB, Hof B. Complexity of the laminar-turbulent boundary in pipe flow. <i>Physical Review Fluids</i>. 2018;3(5). doi:<a href=\"https://doi.org/10.1103/PhysRevFluids.3.054401\">10.1103/PhysRevFluids.3.054401</a>","short":"N.B. Budanur, B. Hof, Physical Review Fluids 3 (2018)."},"arxiv":1,"external_id":{"arxiv":["1802.01918"],"isi":["000433426200001"]},"publisher":"American Physical Society","doi":"10.1103/PhysRevFluids.3.054401","intvolume":"         3","isi":1,"status":"public","issue":"5","article_processing_charge":"No","quality_controlled":"1","article_number":"054401","type":"journal_article","publication_status":"published","author":[{"orcid":"0000-0003-0423-5010","full_name":"Budanur, Nazmi B","first_name":"Nazmi B","id":"3EA1010E-F248-11E8-B48F-1D18A9856A87","last_name":"Budanur"},{"full_name":"Hof, Björn","orcid":"0000-0003-2057-2754","first_name":"Björn","id":"3A374330-F248-11E8-B48F-1D18A9856A87","last_name":"Hof"}]},{"issue":"12","acknowledgement":"The authors thank Philipp Maier and the IST Austria workshop for their dedicated technical support.","status":"public","isi":1,"intvolume":"       120","doi":"10.1103/PhysRevLett.120.124501","publication_status":"published","author":[{"last_name":"Choueiri","first_name":"George H","id":"448BD5BC-F248-11E8-B48F-1D18A9856A87","full_name":"Choueiri, George H"},{"last_name":"Lopez Alonso","full_name":"Lopez Alonso, Jose M","orcid":"0000-0002-0384-2022","first_name":"Jose M","id":"40770848-F248-11E8-B48F-1D18A9856A87"},{"last_name":"Hof","id":"3A374330-F248-11E8-B48F-1D18A9856A87","first_name":"Björn","full_name":"Hof, Björn","orcid":"0000-0003-2057-2754"}],"type":"journal_article","article_number":"124501","article_processing_charge":"No","quality_controlled":"1","department":[{"_id":"BjHo"}],"citation":{"apa":"Choueiri, G. H., Lopez Alonso, J. M., &#38; Hof, B. (2018). Exceeding the asymptotic limit of polymer drag reduction. <i>Physical Review Letters</i>. American Physical Society. <a href=\"https://doi.org/10.1103/PhysRevLett.120.124501\">https://doi.org/10.1103/PhysRevLett.120.124501</a>","short":"G.H. Choueiri, J.M. Lopez Alonso, B. Hof, Physical Review Letters 120 (2018).","ama":"Choueiri GH, Lopez Alonso JM, Hof B. Exceeding the asymptotic limit of polymer drag reduction. <i>Physical Review Letters</i>. 2018;120(12). doi:<a href=\"https://doi.org/10.1103/PhysRevLett.120.124501\">10.1103/PhysRevLett.120.124501</a>","chicago":"Choueiri, George H, Jose M Lopez Alonso, and Björn Hof. “Exceeding the Asymptotic Limit of Polymer Drag Reduction.” <i>Physical Review Letters</i>. American Physical Society, 2018. <a href=\"https://doi.org/10.1103/PhysRevLett.120.124501\">https://doi.org/10.1103/PhysRevLett.120.124501</a>.","ieee":"G. H. Choueiri, J. M. Lopez Alonso, and B. Hof, “Exceeding the asymptotic limit of polymer drag reduction,” <i>Physical Review Letters</i>, vol. 120, no. 12. American Physical Society, 2018.","ista":"Choueiri GH, Lopez Alonso JM, Hof B. 2018. Exceeding the asymptotic limit of polymer drag reduction. Physical Review Letters. 120(12), 124501.","mla":"Choueiri, George H., et al. “Exceeding the Asymptotic Limit of Polymer Drag Reduction.” <i>Physical Review Letters</i>, vol. 120, no. 12, 124501, American Physical Society, 2018, doi:<a href=\"https://doi.org/10.1103/PhysRevLett.120.124501\">10.1103/PhysRevLett.120.124501</a>."},"project":[{"grant_number":"291734","_id":"25681D80-B435-11E9-9278-68D0E5697425","call_identifier":"FP7","name":"International IST Postdoc Fellowship Programme"},{"call_identifier":"FP7","name":"Decoding the complexity of turbulence at its origin","grant_number":"306589","_id":"25152F3A-B435-11E9-9278-68D0E5697425"}],"volume":120,"publist_id":"7537","_id":"328","oa_version":"Preprint","oa":1,"publisher":"American Physical Society","external_id":{"arxiv":["1703.06271"],"isi":["000427804000005"]},"acknowledged_ssus":[{"_id":"SSU"}],"arxiv":1,"title":"Exceeding the asymptotic limit of polymer drag reduction","day":"19","year":"2018","scopus_import":"1","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","date_published":"2018-03-19T00:00:00Z","ec_funded":1,"month":"03","date_created":"2018-12-11T11:45:51Z","publication":"Physical Review Letters","date_updated":"2025-06-04T07:52:00Z","main_file_link":[{"open_access":"1","url":"https://arxiv.org/abs/1703.06271"}],"abstract":[{"text":"The drag of turbulent flows can be drastically decreased by adding small amounts of high molecular weight polymers. While drag reduction initially increases with polymer concentration, it eventually saturates to what is known as the maximum drag reduction (MDR) asymptote; this asymptote is generally attributed to the dynamics being reduced to a marginal yet persistent state of subdued turbulent motion. Contrary to this accepted view, we show that, for an appropriate choice of parameters, polymers can reduce the drag beyond the suggested asymptotic limit, eliminating turbulence and giving way to laminar flow. At higher polymer concentrations, however, the laminar state becomes unstable, resulting in a fluctuating flow with the characteristic drag of the MDR asymptote. Our findings indicate that the asymptotic state is hence dynamically disconnected from ordinary turbulence. © 2018 American Physical Society.","lang":"eng"}],"language":[{"iso":"eng"}],"corr_author":"1"}]