[{"department":[{"_id":"BjHo"}],"date_updated":"2023-10-03T11:07:58Z","type":"journal_article","article_type":"original","keyword":["Condensed Matter Physics","Fluid Flow and Transfer Processes","Mechanics of Materials","Computational Mechanics","Mechanical Engineering"],"status":"public","_id":"12146","issue":"11","volume":34,"publication_status":"published","publication_identifier":{"eissn":["1089-7666"],"issn":["1070-6631"]},"language":[{"iso":"eng"}],"main_file_link":[{"open_access":"1","url":"https://upcommons.upc.edu/handle/2117/385635"}],"scopus_import":"1","intvolume":" 34","month":"11","abstract":[{"text":"In this paper, we explore the stability and dynamical relevance of a wide variety of steady, time-periodic, quasiperiodic, and chaotic flows arising between orthogonally stretching parallel plates. We first explore the stability of all the steady flow solution families formerly identified by Ayats et al. [“Flows between orthogonally stretching parallel plates,” Phys. Fluids 33, 024103 (2021)], concluding that only the one that originates from the Stokesian approximation is actually stable. When both plates are shrinking at identical or nearly the same deceleration rates, this Stokesian flow exhibits a Hopf bifurcation that leads to stable time-periodic regimes. The resulting time-periodic orbits or flows are tracked for different Reynolds numbers and stretching rates while monitoring their Floquet exponents to identify secondary instabilities. It is found that these time-periodic flows also exhibit Neimark–Sacker bifurcations, generating stable quasiperiodic flows (tori) that may sometimes give rise to chaotic dynamics through a Ruelle–Takens–Newhouse scenario. However, chaotic dynamics is unusually observed, as the quasiperiodic flows generally become phase-locked through a resonance mechanism before a strange attractor may arise, thus restoring the time-periodicity of the flow. In this work, we have identified and tracked four different resonance regions, also known as Arnold tongues or horns. In particular, the 1 : 4 strong resonance region is explored in great detail, where the identified scenarios are in very good agreement with normal form theory. ","lang":"eng"}],"oa_version":"Submitted Version","article_processing_charge":"No","external_id":{"isi":["000880665300024"]},"author":[{"first_name":"B.","last_name":"Wang","full_name":"Wang, B."},{"id":"ab77522d-073b-11ed-8aff-e71b39258362","first_name":"Roger","last_name":"Ayats López","orcid":"0000-0001-6572-0621","full_name":"Ayats López, Roger"},{"first_name":"A.","full_name":"Meseguer, A.","last_name":"Meseguer"},{"first_name":"F.","last_name":"Marques","full_name":"Marques, F."}],"title":"Phase-locking flows between orthogonally stretching parallel plates","citation":{"mla":"Wang, B., et al. “Phase-Locking Flows between Orthogonally Stretching Parallel Plates.” Physics of Fluids, vol. 34, no. 11, 114111, AIP Publishing, 2022, doi:10.1063/5.0124152.","ama":"Wang B, Ayats López R, Meseguer A, Marques F. Phase-locking flows between orthogonally stretching parallel plates. Physics of Fluids. 2022;34(11). doi:10.1063/5.0124152","apa":"Wang, B., Ayats López, R., Meseguer, A., & Marques, F. (2022). Phase-locking flows between orthogonally stretching parallel plates. Physics of Fluids. AIP Publishing. https://doi.org/10.1063/5.0124152","short":"B. Wang, R. Ayats López, A. Meseguer, F. Marques, Physics of Fluids 34 (2022).","ieee":"B. Wang, R. Ayats López, A. Meseguer, and F. Marques, “Phase-locking flows between orthogonally stretching parallel plates,” Physics of Fluids, vol. 34, no. 11. AIP Publishing, 2022.","chicago":"Wang, B., Roger Ayats López, A. Meseguer, and F. Marques. “Phase-Locking Flows between Orthogonally Stretching Parallel Plates.” Physics of Fluids. AIP Publishing, 2022. https://doi.org/10.1063/5.0124152.","ista":"Wang B, Ayats López R, Meseguer A, Marques F. 2022. Phase-locking flows between orthogonally stretching parallel plates. Physics of Fluids. 34(11), 114111."},"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","article_number":"114111","date_created":"2023-01-12T12:06:58Z","date_published":"2022-11-04T00:00:00Z","doi":"10.1063/5.0124152","year":"2022","isi":1,"publication":"Physics of Fluids","day":"04","oa":1,"quality_controlled":"1","publisher":"AIP Publishing","acknowledgement":"This work was supported by the Spanish MINECO under Grant Nos. FIS2017-85794-P and PRX18/00179, the Spanish MICINN through Grant No. PID2020-114043GB-I00, and the\r\nGeneralitat de Catalunya under Grant No. 2017-SGR-785. B.W.’s research was also supported by the Chinese Scholarship Council through Grant CSC No. 201806440152."},{"citation":{"chicago":"Hansen, Andi H, Florian Pauler, Michael Riedl, Carmen Streicher, Anna-Magdalena Heger, Susanne Laukoter, Christoph M Sommer, et al. “Tissue-Wide Effects Override Cell-Intrinsic Gene Function in Radial Neuron Migration.” Oxford Open Neuroscience. Oxford Academic, 2022. https://doi.org/10.1093/oons/kvac009.","ista":"Hansen AH, Pauler F, Riedl M, Streicher C, Heger A-M, Laukoter S, Sommer CM, Nicolas A, Hof B, Tsai LH, Rülicke T, Hippenmeyer S. 2022. Tissue-wide effects override cell-intrinsic gene function in radial neuron migration. Oxford Open Neuroscience. 1(1), kvac009.","mla":"Hansen, Andi H., et al. “Tissue-Wide Effects Override Cell-Intrinsic Gene Function in Radial Neuron Migration.” Oxford Open Neuroscience, vol. 1, no. 1, kvac009, Oxford Academic, 2022, doi:10.1093/oons/kvac009.","apa":"Hansen, A. H., Pauler, F., Riedl, M., Streicher, C., Heger, A.-M., Laukoter, S., … Hippenmeyer, S. (2022). Tissue-wide effects override cell-intrinsic gene function in radial neuron migration. Oxford Open Neuroscience. Oxford Academic. https://doi.org/10.1093/oons/kvac009","ama":"Hansen AH, Pauler F, Riedl M, et al. Tissue-wide effects override cell-intrinsic gene function in radial neuron migration. Oxford Open Neuroscience. 2022;1(1). doi:10.1093/oons/kvac009","short":"A.H. Hansen, F. Pauler, M. Riedl, C. Streicher, A.-M. Heger, S. Laukoter, C.M. Sommer, A. Nicolas, B. Hof, L.H. Tsai, T. Rülicke, S. Hippenmeyer, Oxford Open Neuroscience 1 (2022).","ieee":"A. H. Hansen et al., “Tissue-wide effects override cell-intrinsic gene function in radial neuron migration,” Oxford Open Neuroscience, vol. 1, no. 1. Oxford Academic, 2022."},"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","article_processing_charge":"No","author":[{"first_name":"Andi H","id":"38853E16-F248-11E8-B48F-1D18A9856A87","full_name":"Hansen, Andi H","last_name":"Hansen"},{"id":"48EA0138-F248-11E8-B48F-1D18A9856A87","first_name":"Florian","full_name":"Pauler, Florian","orcid":"0000-0002-7462-0048","last_name":"Pauler"},{"first_name":"Michael","id":"3BE60946-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0003-4844-6311","full_name":"Riedl, Michael","last_name":"Riedl"},{"first_name":"Carmen","id":"36BCB99C-F248-11E8-B48F-1D18A9856A87","last_name":"Streicher","full_name":"Streicher, Carmen"},{"first_name":"Anna-Magdalena","id":"4B76FFD2-F248-11E8-B48F-1D18A9856A87","full_name":"Heger, Anna-Magdalena","last_name":"Heger"},{"orcid":"0000-0002-7903-3010","full_name":"Laukoter, Susanne","last_name":"Laukoter","first_name":"Susanne","id":"2D6B7A9A-F248-11E8-B48F-1D18A9856A87"},{"first_name":"Christoph M","id":"4DF26D8C-F248-11E8-B48F-1D18A9856A87","full_name":"Sommer, Christoph M","orcid":"0000-0003-1216-9105","last_name":"Sommer"},{"id":"2A103192-F248-11E8-B48F-1D18A9856A87","first_name":"Armel","last_name":"Nicolas","full_name":"Nicolas, Armel"},{"id":"3A374330-F248-11E8-B48F-1D18A9856A87","first_name":"Björn","orcid":"0000-0003-2057-2754","full_name":"Hof, Björn","last_name":"Hof"},{"last_name":"Tsai","full_name":"Tsai, Li Huei","first_name":"Li Huei"},{"first_name":"Thomas","full_name":"Rülicke, Thomas","last_name":"Rülicke"},{"first_name":"Simon","id":"37B36620-F248-11E8-B48F-1D18A9856A87","last_name":"Hippenmeyer","full_name":"Hippenmeyer, Simon","orcid":"0000-0003-2279-1061"}],"title":"Tissue-wide effects override cell-intrinsic gene function in radial neuron migration","article_number":"kvac009","project":[{"name":"Molecular Mechanisms of Cerebral Cortex Development","grant_number":"618444","call_identifier":"FP7","_id":"25D61E48-B435-11E9-9278-68D0E5697425"},{"name":"Molecular Mechanisms of Radial Neuronal Migration","grant_number":"24812","_id":"2625A13E-B435-11E9-9278-68D0E5697425"}],"year":"2022","has_accepted_license":"1","publication":"Oxford Open Neuroscience","day":"07","date_created":"2022-02-25T07:52:11Z","date_published":"2022-07-07T00:00:00Z","doi":"10.1093/oons/kvac009","acknowledgement":"A.H.H. was a recipient of a DOC Fellowship (24812) of the Austrian Academy of Sciences. This work also received support from IST Austria institutional funds; the People Programme (Marie Curie Actions) of the European Union’s Seventh Framework Programme (FP7/2007–2013) under REA grant agreement No 618444 to S.H.\r\nAPC funding was obtained by IST Austria institutional funds.\r\nWe thank A. Sommer and C. Czepe (VBCF GmbH, NGS Unit), L. Andersen, J. Sonntag and J. Renno for technical support and/or initial experiments; M. Sixt, J. Nimpf and all members of the Hippenmeyer lab for discussion. This research was supported by the Scientific Service Units of IST Austria through resources provided by the Imaging and Optics Facility, Lab Support Facility and Preclinical Facility.","oa":1,"publisher":"Oxford Academic","quality_controlled":"1","date_updated":"2023-11-30T10:55:12Z","ddc":["570"],"file_date_updated":"2023-08-16T08:00:30Z","department":[{"_id":"SiHi"},{"_id":"BjHo"},{"_id":"LifeSc"},{"_id":"EM-Fac"}],"_id":"10791","tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)"},"type":"journal_article","article_type":"original","status":"public","publication_status":"published","publication_identifier":{"eissn":["2753-149X"]},"language":[{"iso":"eng"}],"file":[{"file_id":"14061","checksum":"822e76e056c07099d1fb27d1ece5941b","success":1,"content_type":"application/pdf","access_level":"open_access","relation":"main_file","date_created":"2023-08-16T08:00:30Z","file_name":"2023_OxfordOpenNeuroscience_Hansen.pdf","date_updated":"2023-08-16T08:00:30Z","file_size":4846551,"creator":"dernst"}],"ec_funded":1,"issue":"1","related_material":{"record":[{"relation":"dissertation_contains","status":"public","id":"12726"},{"id":"14530","status":"public","relation":"dissertation_contains"}]},"volume":1,"abstract":[{"text":"The mammalian neocortex is composed of diverse neuronal and glial cell classes that broadly arrange in six distinct laminae. Cortical layers emerge during development and defects in the developmental programs that orchestrate cortical lamination are associated with neurodevelopmental diseases. The developmental principle of cortical layer formation depends on concerted radial projection neuron migration, from their birthplace to their final target position. Radial migration occurs in defined sequential steps, regulated by a large array of signaling pathways. However, based on genetic loss-of-function experiments, most studies have thus far focused on the role of cell-autonomous gene function. Yet, cortical neuron migration in situ is a complex process and migrating neurons traverse along diverse cellular compartments and environments. The role of tissue-wide properties and genetic state in radial neuron migration is however not clear. Here we utilized mosaic analysis with double markers (MADM) technology to either sparsely or globally delete gene function, followed by quantitative single-cell phenotyping. The MADM-based gene ablation paradigms in combination with computational modeling demonstrated that global tissue-wide effects predominate cell-autonomous gene function albeit in a gene-specific manner. Our results thus suggest that the genetic landscape in a tissue critically affects the overall migration phenotype of individual cortical projection neurons. In a broader context, our findings imply that global tissue-wide effects represent an essential component of the underlying etiology associated with focal malformations of cortical development in particular, and neurological diseases in general.","lang":"eng"}],"acknowledged_ssus":[{"_id":"LifeSc"},{"_id":"PreCl"},{"_id":"Bio"}],"oa_version":"Published Version","intvolume":" 1","month":"07"},{"language":[{"iso":"eng"}],"publication_identifier":{"issn":["1534-5807"],"eissn":["1878-1551"]},"publication_status":"published","related_material":{"record":[{"id":"12726","status":"public","relation":"dissertation_contains"},{"id":"14530","status":"public","relation":"dissertation_contains"},{"relation":"dissertation_contains","id":"12401","status":"public"}]},"issue":"1","volume":57,"ec_funded":1,"pmid":1,"oa_version":"Published Version","acknowledged_ssus":[{"_id":"LifeSc"},{"_id":"Bio"},{"_id":"EM-Fac"}],"abstract":[{"text":"When crawling through the body, leukocytes often traverse tissues that are densely packed with extracellular matrix and other cells, and this raises the question: How do leukocytes overcome compressive mechanical loads? Here, we show that the actin cortex of leukocytes is mechanoresponsive and that this responsiveness requires neither force sensing via the nucleus nor adhesive interactions with a substrate. Upon global compression of the cell body as well as local indentation of the plasma membrane, Wiskott-Aldrich syndrome protein (WASp) assembles into dot-like structures, providing activation platforms for Arp2/3 nucleated actin patches. These patches locally push against the external load, which can be obstructing collagen fibers or other cells, and thereby create space to facilitate forward locomotion. We show in vitro and in vivo that this WASp function is rate limiting for ameboid leukocyte migration in dense but not in loose environments and is required for trafficking through diverse tissues such as skin and lymph nodes.","lang":"eng"}],"month":"01","intvolume":" 57","scopus_import":"1","main_file_link":[{"open_access":"1","url":"https://www.sciencedirect.com/science/article/pii/S1534580721009497"}],"ddc":["570"],"date_updated":"2024-03-27T23:30:23Z","department":[{"_id":"MiSi"},{"_id":"EM-Fac"},{"_id":"NanoFab"},{"_id":"BjHo"}],"_id":"10703","status":"public","type":"journal_article","article_type":"original","tmp":{"short":"CC BY-NC-ND (4.0)","name":"Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)","legal_code_url":"https://creativecommons.org/licenses/by-nc-nd/4.0/legalcode","image":"/images/cc_by_nc_nd.png"},"day":"10","publication":"Developmental Cell","isi":1,"year":"2022","doi":"10.1016/j.devcel.2021.11.024","date_published":"2022-01-10T00:00:00Z","date_created":"2022-01-30T23:01:33Z","page":"47-62.e9","acknowledgement":"We thank N. Darwish-Miranda, F. Leite, F.P. Assen, and A. Eichner for advice and help with experiments. We thank J. Renkawitz, E. Kiermaier, A. Juanes Garcia, and M. Avellaneda for critical reading of the manuscript. We thank M. Driscoll for advice on fluorescent labeling of collagen gels. This research was supported by the Scientific Service Units (SSUs) of IST Austria through resources provided by Molecular Biology Services/Lab Support Facility (LSF)/Bioimaging Facility/Electron Microscopy Facility. This work was funded by grants from the European Research Council ( CoG 724373 ) and the Austrian Science Foundation (FWF) to M.S. F.G. received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement no. 747687.","publisher":"Cell Press ; Elsevier","quality_controlled":"1","oa":1,"user_id":"4359f0d1-fa6c-11eb-b949-802e58b17ae8","citation":{"mla":"Gaertner, Florian, et al. “WASp Triggers Mechanosensitive Actin Patches to Facilitate Immune Cell Migration in Dense Tissues.” Developmental Cell, vol. 57, no. 1, Cell Press ; Elsevier, 2022, p. 47–62.e9, doi:10.1016/j.devcel.2021.11.024.","ieee":"F. Gaertner et al., “WASp triggers mechanosensitive actin patches to facilitate immune cell migration in dense tissues,” Developmental Cell, vol. 57, no. 1. Cell Press ; Elsevier, p. 47–62.e9, 2022.","short":"F. Gaertner, P. Reis-Rodrigues, I. de Vries, M. Hons, J. Aguilera, M. Riedl, A.F. Leithner, S. Tasciyan, A. Kopf, J. Merrin, V. Zheden, W. Kaufmann, R. Hauschild, M.K. Sixt, Developmental Cell 57 (2022) 47–62.e9.","ama":"Gaertner F, Reis-Rodrigues P, de Vries I, et al. WASp triggers mechanosensitive actin patches to facilitate immune cell migration in dense tissues. Developmental Cell. 2022;57(1):47-62.e9. doi:10.1016/j.devcel.2021.11.024","apa":"Gaertner, F., Reis-Rodrigues, P., de Vries, I., Hons, M., Aguilera, J., Riedl, M., … Sixt, M. K. (2022). WASp triggers mechanosensitive actin patches to facilitate immune cell migration in dense tissues. Developmental Cell. Cell Press ; Elsevier. https://doi.org/10.1016/j.devcel.2021.11.024","chicago":"Gaertner, Florian, Patricia Reis-Rodrigues, Ingrid de Vries, Miroslav Hons, Juan Aguilera, Michael Riedl, Alexander F Leithner, et al. “WASp Triggers Mechanosensitive Actin Patches to Facilitate Immune Cell Migration in Dense Tissues.” Developmental Cell. Cell Press ; Elsevier, 2022. https://doi.org/10.1016/j.devcel.2021.11.024.","ista":"Gaertner F, Reis-Rodrigues P, de Vries I, Hons M, Aguilera J, Riedl M, Leithner AF, Tasciyan S, Kopf A, Merrin J, Zheden V, Kaufmann W, Hauschild R, Sixt MK. 2022. WASp triggers mechanosensitive actin patches to facilitate immune cell migration in dense tissues. Developmental Cell. 57(1), 47–62.e9."},"title":"WASp triggers mechanosensitive actin patches to facilitate immune cell migration in dense tissues","author":[{"last_name":"Gaertner","full_name":"Gaertner, Florian","first_name":"Florian"},{"full_name":"Reis-Rodrigues, Patricia","last_name":"Reis-Rodrigues","first_name":"Patricia"},{"id":"4C7D837E-F248-11E8-B48F-1D18A9856A87","first_name":"Ingrid","full_name":"De Vries, Ingrid","last_name":"De Vries"},{"id":"4167FE56-F248-11E8-B48F-1D18A9856A87","first_name":"Miroslav","orcid":"0000-0002-6625-3348","full_name":"Hons, Miroslav","last_name":"Hons"},{"last_name":"Aguilera","full_name":"Aguilera, Juan","first_name":"Juan"},{"first_name":"Michael","id":"3BE60946-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0003-4844-6311","full_name":"Riedl, Michael","last_name":"Riedl"},{"last_name":"Leithner","orcid":"0000-0002-1073-744X","full_name":"Leithner, Alexander F","id":"3B1B77E4-F248-11E8-B48F-1D18A9856A87","first_name":"Alexander F"},{"first_name":"Saren","id":"4323B49C-F248-11E8-B48F-1D18A9856A87","last_name":"Tasciyan","orcid":"0000-0003-1671-393X","full_name":"Tasciyan, Saren"},{"first_name":"Aglaja","id":"31DAC7B6-F248-11E8-B48F-1D18A9856A87","full_name":"Kopf, Aglaja","orcid":"0000-0002-2187-6656","last_name":"Kopf"},{"id":"4515C308-F248-11E8-B48F-1D18A9856A87","first_name":"Jack","orcid":"0000-0001-5145-4609","full_name":"Merrin, Jack","last_name":"Merrin"},{"last_name":"Zheden","orcid":"0000-0002-9438-4783","full_name":"Zheden, Vanessa","id":"39C5A68A-F248-11E8-B48F-1D18A9856A87","first_name":"Vanessa"},{"full_name":"Kaufmann, Walter","orcid":"0000-0001-9735-5315","last_name":"Kaufmann","id":"3F99E422-F248-11E8-B48F-1D18A9856A87","first_name":"Walter"},{"first_name":"Robert","id":"4E01D6B4-F248-11E8-B48F-1D18A9856A87","last_name":"Hauschild","orcid":"0000-0001-9843-3522","full_name":"Hauschild, Robert"},{"last_name":"Sixt","full_name":"Sixt, Michael K","orcid":"0000-0002-6620-9179","first_name":"Michael K","id":"41E9FBEA-F248-11E8-B48F-1D18A9856A87"}],"article_processing_charge":"No","external_id":{"isi":["000768933800005"],"pmid":["34919802"]},"project":[{"call_identifier":"H2020","_id":"260AA4E2-B435-11E9-9278-68D0E5697425","name":"Mechanical Adaptation of Lamellipodial Actin Networks in Migrating Cells","grant_number":"747687"},{"name":"Cellular navigation along spatial gradients","grant_number":"724373","_id":"25FE9508-B435-11E9-9278-68D0E5697425","call_identifier":"H2020"}]},{"acknowledgement":"This research was funded by the Central Research Development Fund of the University of\r\nBremen grant number ZF04B /2019/FB04 Avila_Kerstin (“Independent Project for Postdocs”). Shreyas Jalikop is acknowledged for recording some of the lifetime measurements\r\n","publisher":"MDPI","quality_controlled":"1","oa":1,"has_accepted_license":"1","isi":1,"year":"2021","day":"01","publication":"Entropy","date_published":"2021-01-01T00:00:00Z","doi":"10.3390/e23010058","date_created":"2021-01-10T23:01:17Z","article_number":"58","citation":{"ama":"Avila K, Hof B. Second-order phase transition in counter-rotating taylor-couette flow experiment. Entropy. 2021;23(1). doi:10.3390/e23010058","apa":"Avila, K., & Hof, B. (2021). Second-order phase transition in counter-rotating taylor-couette flow experiment. Entropy. MDPI. https://doi.org/10.3390/e23010058","short":"K. Avila, B. Hof, Entropy 23 (2021).","ieee":"K. Avila and B. Hof, “Second-order phase transition in counter-rotating taylor-couette flow experiment,” Entropy, vol. 23, no. 1. MDPI, 2021.","mla":"Avila, Kerstin, and Björn Hof. “Second-Order Phase Transition in Counter-Rotating Taylor-Couette Flow Experiment.” Entropy, vol. 23, no. 1, 58, MDPI, 2021, doi:10.3390/e23010058.","ista":"Avila K, Hof B. 2021. Second-order phase transition in counter-rotating taylor-couette flow experiment. Entropy. 23(1), 58.","chicago":"Avila, Kerstin, and Björn Hof. “Second-Order Phase Transition in Counter-Rotating Taylor-Couette Flow Experiment.” Entropy. MDPI, 2021. https://doi.org/10.3390/e23010058."},"user_id":"4359f0d1-fa6c-11eb-b949-802e58b17ae8","author":[{"id":"fcf74381-53e1-11eb-a6dc-b0e2acf78757","first_name":"Kerstin","last_name":"Avila","full_name":"Avila, Kerstin"},{"id":"3A374330-F248-11E8-B48F-1D18A9856A87","first_name":"Björn","last_name":"Hof","orcid":"0000-0003-2057-2754","full_name":"Hof, Björn"}],"external_id":{"pmid":["33396499"],"isi":["000610135400001"]},"article_processing_charge":"No","title":"Second-order phase transition in counter-rotating taylor-couette flow experiment","abstract":[{"text":"In many basic shear flows, such as pipe, Couette, and channel flow, turbulence does not\r\narise from an instability of the laminar state, and both dynamical states co-exist. With decreasing flow speed (i.e., decreasing Reynolds number) the fraction of fluid in laminar motion increases while turbulence recedes and eventually the entire flow relaminarizes. The first step towards understanding the nature of this transition is to determine if the phase change is of either first or second order. In the former case, the turbulent fraction would drop discontinuously to zero as the Reynolds number decreases while in the latter the process would be continuous. For Couette flow, the flow between two parallel plates, earlier studies suggest a discontinuous scenario. In the present study we realize a Couette flow between two concentric cylinders which allows studies to be carried out in large aspect ratios and for extensive observation times. The presented measurements show that the transition in this circular Couette geometry is continuous suggesting that former studies were limited by finite size effects. A further characterization of this transition, in particular its relation to the directed percolation universality class, requires even larger system sizes than presently available. ","lang":"eng"}],"oa_version":"Published Version","pmid":1,"scopus_import":"1","month":"01","intvolume":" 23","publication_identifier":{"eissn":["1099-4300"]},"publication_status":"published","file":[{"creator":"dernst","file_size":9456389,"date_updated":"2021-01-11T07:50:32Z","file_name":"2021_Entropy_Avila.pdf","date_created":"2021-01-11T07:50:32Z","relation":"main_file","access_level":"open_access","content_type":"application/pdf","success":1,"file_id":"9003","checksum":"3ba3dd8b7eecff713b72c5e9ba30d626"}],"language":[{"iso":"eng"}],"volume":23,"issue":"1","_id":"8999","type":"journal_article","article_type":"original","tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)"},"status":"public","date_updated":"2023-08-07T13:31:07Z","ddc":["530"],"file_date_updated":"2021-01-11T07:50:32Z","department":[{"_id":"BjHo"}]},{"ec_funded":1,"volume":912,"language":[{"iso":"eng"}],"file":[{"file_id":"9220","checksum":"b8020d6338667673e34fde0608913dd2","success":1,"access_level":"open_access","relation":"main_file","content_type":"application/pdf","date_created":"2021-03-03T09:49:34Z","file_name":"2021_JourFluidMechanics_Klotz.pdf","creator":"dernst","date_updated":"2021-03-03T09:49:34Z","file_size":4124471}],"publication_status":"published","publication_identifier":{"eissn":["1469-7645"],"issn":["0022-1120"]},"intvolume":" 912","month":"02","scopus_import":"1","oa_version":"Published Version","abstract":[{"text":"In this paper we experimentally study the transitional range of Reynolds numbers in\r\nplane Couette–Poiseuille flow, focusing our attention on the localized turbulent structures\r\ntriggered by a strong impulsive jet and the large-scale flow generated around these\r\nstructures. We present a detailed investigation of the large-scale flow and show how\r\nits amplitude depends on Reynolds number and amplitude perturbation. In addition,\r\nwe characterize the initial dynamics of the localized turbulent spot, which includes the\r\ncoupling between the small and large scales, as well as the dependence of the advection\r\nspeed on the large-scale flow generated around the spot. Finally, we provide the first\r\nexperimental measurements of the large-scale flow around an oblique turbulent band.","lang":"eng"}],"file_date_updated":"2021-03-03T09:49:34Z","department":[{"_id":"BjHo"}],"ddc":["530"],"date_updated":"2023-08-07T13:55:40Z","status":"public","tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)"},"article_type":"original","type":"journal_article","_id":"9207","date_created":"2021-02-28T23:01:25Z","doi":"10.1017/jfm.2020.1089","date_published":"2021-02-15T00:00:00Z","publication":"Journal of Fluid Mechanics","day":"15","year":"2021","isi":1,"has_accepted_license":"1","oa":1,"quality_controlled":"1","publisher":"Cambridge University Press","acknowledgement":"We thank Y. Duguet, S. Gomé, G. Lemoult, T. Liu, B. Semin and L.S. Tuckerman for\r\nfruitful discussions. \r\nThis work was supported by a grant, TRANSFLOW, provided by the Agence Nationale de\r\nla Recherche (ANR). A.M.P. was partially supported by the French Embassy in Russia (I.I. Mechnikov scholarship) and by the Russian Science Foundation (project no. 18-79-00189). L.K. was partially supported by the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement no. 754411.","title":"Experimental measurements in plane Couette-Poiseuille flow: Dynamics of the large- and small-scale flow","external_id":{"isi":["000618034400001"]},"article_processing_charge":"Yes (via OA deal)","author":[{"first_name":"Lukasz","id":"2C9AF1C2-F248-11E8-B48F-1D18A9856A87","last_name":"Klotz","orcid":"0000-0003-1740-7635","full_name":"Klotz, Lukasz"},{"first_name":"A. M.","full_name":"Pavlenko, A. M.","last_name":"Pavlenko"},{"first_name":"J. E.","full_name":"Wesfreid, J. E.","last_name":"Wesfreid"}],"user_id":"4359f0d1-fa6c-11eb-b949-802e58b17ae8","citation":{"ista":"Klotz L, Pavlenko AM, Wesfreid JE. 2021. Experimental measurements in plane Couette-Poiseuille flow: Dynamics of the large- and small-scale flow. Journal of Fluid Mechanics. 912, A24.","chicago":"Klotz, Lukasz, A. M. Pavlenko, and J. E. Wesfreid. “Experimental Measurements in Plane Couette-Poiseuille Flow: Dynamics of the Large- and Small-Scale Flow.” Journal of Fluid Mechanics. Cambridge University Press, 2021. https://doi.org/10.1017/jfm.2020.1089.","short":"L. Klotz, A.M. Pavlenko, J.E. Wesfreid, Journal of Fluid Mechanics 912 (2021).","ieee":"L. Klotz, A. M. Pavlenko, and J. E. Wesfreid, “Experimental measurements in plane Couette-Poiseuille flow: Dynamics of the large- and small-scale flow,” Journal of Fluid Mechanics, vol. 912. Cambridge University Press, 2021.","apa":"Klotz, L., Pavlenko, A. M., & Wesfreid, J. E. (2021). Experimental measurements in plane Couette-Poiseuille flow: Dynamics of the large- and small-scale flow. Journal of Fluid Mechanics. Cambridge University Press. https://doi.org/10.1017/jfm.2020.1089","ama":"Klotz L, Pavlenko AM, Wesfreid JE. Experimental measurements in plane Couette-Poiseuille flow: Dynamics of the large- and small-scale flow. Journal of Fluid Mechanics. 2021;912. doi:10.1017/jfm.2020.1089","mla":"Klotz, Lukasz, et al. “Experimental Measurements in Plane Couette-Poiseuille Flow: Dynamics of the Large- and Small-Scale Flow.” Journal of Fluid Mechanics, vol. 912, A24, Cambridge University Press, 2021, doi:10.1017/jfm.2020.1089."},"project":[{"call_identifier":"H2020","_id":"260C2330-B435-11E9-9278-68D0E5697425","grant_number":"754411","name":"ISTplus - Postdoctoral Fellowships"}],"article_number":"A24"},{"volume":915,"publication_status":"published","publication_identifier":{"eissn":["1469-7645"],"issn":["0022-1120"]},"language":[{"iso":"eng"}],"main_file_link":[{"url":"https://arxiv.org/abs/2008.08851","open_access":"1"}],"scopus_import":"1","intvolume":" 915","month":"03","abstract":[{"text":"We report the results of an experimental investigation into the decay of turbulence in plane Couette–Poiseuille flow using ‘quench’ experiments where the flow laminarises after a sudden reduction in Reynolds number Re. Specifically, we study the velocity field in the streamwise–spanwise plane. We show that the spanwise velocity containing rolls decays faster than the streamwise velocity, which displays elongated regions of higher or lower velocity called streaks. At final Reynolds numbers above 425, the decay of streaks displays two stages: first a slow decay when rolls are present and secondly a more rapid decay of streaks alone. The difference in behaviour results from the regeneration of streaks by rolls, called the lift-up effect. We define the turbulent fraction as the portion of the flow containing turbulence and this is estimated by thresholding the spanwise velocity component. It decreases linearly with time in the whole range of final Re. The corresponding decay slope increases linearly with final Re. The extrapolated value at which this decay slope vanishes is Reaz≈656±10, close to Reg≈670 at which turbulence is self-sustained. The decay of the energy computed from the spanwise velocity component is found to be exponential. The corresponding decay rate increases linearly with Re, with an extrapolated vanishing value at ReAz≈688±10. This value is also close to the value at which the turbulence is self-sustained, showing that valuable information on the transition can be obtained over a wide range of Re.","lang":"eng"}],"oa_version":"Preprint","department":[{"_id":"BjHo"}],"date_updated":"2023-08-07T14:30:11Z","article_type":"original","type":"journal_article","status":"public","_id":"9297","date_created":"2021-03-28T22:01:42Z","doi":"10.1017/jfm.2021.89","date_published":"2021-03-17T00:00:00Z","year":"2021","isi":1,"publication":"Journal of Fluid Mechanics","day":"17","oa":1,"publisher":"Cambridge University Press","quality_controlled":"1","acknowledgement":"We gratefully acknowledge Joran Rolland, Yohann Duguet, Romain Monchaux, S´ebastien Gom´e, Laurette Tuckerman, Dwight Barkley, Olivier Dauchot and Sabine Bottin for fruitful discussions. We thank Xavier Benoit-Gonin, Amaury Fourgeaud, Thierry Darnige, Olivier Brouard and Justine Laurent for technical help. This work has benefited from the ANR TransFlow, and by starting grants obtained by B.S. from CNRS (INSIS) and ESPCI. T.M. was\r\nsupported by a Joliot visiting professorship grant from ESPCI.","article_processing_charge":"No","external_id":{"arxiv":["2008.08851"],"isi":["000629677500001"]},"author":[{"first_name":"T.","last_name":"Liu","full_name":"Liu, T."},{"full_name":"Semin, B.","last_name":"Semin","first_name":"B."},{"first_name":"Lukasz","id":"2C9AF1C2-F248-11E8-B48F-1D18A9856A87","full_name":"Klotz, Lukasz","orcid":"0000-0003-1740-7635","last_name":"Klotz"},{"last_name":"Godoy-Diana","full_name":"Godoy-Diana, R.","first_name":"R."},{"full_name":"Wesfreid, J. E.","last_name":"Wesfreid","first_name":"J. E."},{"first_name":"T.","full_name":"Mullin, T.","last_name":"Mullin"}],"title":"Decay of streaks and rolls in plane Couette-Poiseuille flow","citation":{"chicago":"Liu, T., B. Semin, Lukasz Klotz, R. Godoy-Diana, J. E. Wesfreid, and T. Mullin. “Decay of Streaks and Rolls in Plane Couette-Poiseuille Flow.” Journal of Fluid Mechanics. Cambridge University Press, 2021. https://doi.org/10.1017/jfm.2021.89.","ista":"Liu T, Semin B, Klotz L, Godoy-Diana R, Wesfreid JE, Mullin T. 2021. Decay of streaks and rolls in plane Couette-Poiseuille flow. Journal of Fluid Mechanics. 915, A65.","mla":"Liu, T., et al. “Decay of Streaks and Rolls in Plane Couette-Poiseuille Flow.” Journal of Fluid Mechanics, vol. 915, A65, Cambridge University Press, 2021, doi:10.1017/jfm.2021.89.","ama":"Liu T, Semin B, Klotz L, Godoy-Diana R, Wesfreid JE, Mullin T. Decay of streaks and rolls in plane Couette-Poiseuille flow. Journal of Fluid Mechanics. 2021;915. doi:10.1017/jfm.2021.89","apa":"Liu, T., Semin, B., Klotz, L., Godoy-Diana, R., Wesfreid, J. E., & Mullin, T. (2021). Decay of streaks and rolls in plane Couette-Poiseuille flow. Journal of Fluid Mechanics. Cambridge University Press. https://doi.org/10.1017/jfm.2021.89","short":"T. Liu, B. Semin, L. Klotz, R. Godoy-Diana, J.E. Wesfreid, T. Mullin, Journal of Fluid Mechanics 915 (2021).","ieee":"T. Liu, B. Semin, L. Klotz, R. Godoy-Diana, J. E. Wesfreid, and T. Mullin, “Decay of streaks and rolls in plane Couette-Poiseuille flow,” Journal of Fluid Mechanics, vol. 915. Cambridge University Press, 2021."},"user_id":"4359f0d1-fa6c-11eb-b949-802e58b17ae8","article_number":"A65"},{"user_id":"4359f0d1-fa6c-11eb-b949-802e58b17ae8","citation":{"ista":"Scarselli D, Budanur NB, Timme M, Hof B. 2021. Discontinuous epidemic transition due to limited testing. Nature Communications. 12(1), 2586.","chicago":"Scarselli, Davide, Nazmi B Budanur, Marc Timme, and Björn Hof. “Discontinuous Epidemic Transition Due to Limited Testing.” Nature Communications. Springer Nature, 2021. https://doi.org/10.1038/s41467-021-22725-9.","apa":"Scarselli, D., Budanur, N. B., Timme, M., & Hof, B. (2021). Discontinuous epidemic transition due to limited testing. Nature Communications. Springer Nature. https://doi.org/10.1038/s41467-021-22725-9","ama":"Scarselli D, Budanur NB, Timme M, Hof B. Discontinuous epidemic transition due to limited testing. Nature Communications. 2021;12(1). doi:10.1038/s41467-021-22725-9","ieee":"D. Scarselli, N. B. Budanur, M. Timme, and B. Hof, “Discontinuous epidemic transition due to limited testing,” Nature Communications, vol. 12, no. 1. Springer Nature, 2021.","short":"D. Scarselli, N.B. Budanur, M. Timme, B. Hof, Nature Communications 12 (2021).","mla":"Scarselli, Davide, et al. “Discontinuous Epidemic Transition Due to Limited Testing.” Nature Communications, vol. 12, no. 1, 2586, Springer Nature, 2021, doi:10.1038/s41467-021-22725-9."},"title":"Discontinuous epidemic transition due to limited testing","author":[{"last_name":"Scarselli","full_name":"Scarselli, Davide","orcid":"0000-0001-5227-4271","id":"40315C30-F248-11E8-B48F-1D18A9856A87","first_name":"Davide"},{"orcid":"0000-0003-0423-5010","full_name":"Budanur, Nazmi B","last_name":"Budanur","first_name":"Nazmi B","id":"3EA1010E-F248-11E8-B48F-1D18A9856A87"},{"first_name":"Marc","last_name":"Timme","full_name":"Timme, Marc"},{"first_name":"Björn","id":"3A374330-F248-11E8-B48F-1D18A9856A87","last_name":"Hof","orcid":"0000-0003-2057-2754","full_name":"Hof, Björn"}],"external_id":{"isi":["000687305500044"]},"article_processing_charge":"No","article_number":"2586","day":"10","publication":"Nature Communications","has_accepted_license":"1","isi":1,"year":"2021","doi":"10.1038/s41467-021-22725-9","date_published":"2021-05-10T00:00:00Z","date_created":"2021-05-23T22:01:42Z","acknowledgement":"The authors thank Malte Schröder for valuable discussions and creating the scale-free network topologies. B.H. thanks Mukund Vasudevan for helpful discussion. The research by M.T. was supported by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany´s Excellence Strategy–EXC-2068–390729961–Cluster of Excellence Physics of Life of TU Dresden.","quality_controlled":"1","publisher":"Springer Nature","oa":1,"ddc":["570"],"date_updated":"2023-08-08T13:45:13Z","department":[{"_id":"BjHo"}],"file_date_updated":"2021-05-25T14:18:40Z","_id":"9407","status":"public","type":"journal_article","article_type":"original","tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)"},"file":[{"date_updated":"2021-05-25T14:18:40Z","file_size":1176573,"creator":"kschuh","date_created":"2021-05-25T14:18:40Z","file_name":"2021_NatureCommunications_Scarselli.pdf","content_type":"application/pdf","access_level":"open_access","relation":"main_file","file_id":"9426","checksum":"fe26c1b8a7da1ae07a6c03f80ff06ea1","success":1}],"language":[{"iso":"eng"}],"publication_identifier":{"eissn":["20411723"]},"publication_status":"published","related_material":{"link":[{"relation":"press_release","url":"https://ist.ac.at/en/news/smashing-the-covid-curve/","description":"News on IST Homepage"}]},"issue":"1","volume":12,"oa_version":"Published Version","abstract":[{"text":"High impact epidemics constitute one of the largest threats humanity is facing in the 21st century. In the absence of pharmaceutical interventions, physical distancing together with testing, contact tracing and quarantining are crucial in slowing down epidemic dynamics. Yet, here we show that if testing capacities are limited, containment may fail dramatically because such combined countermeasures drastically change the rules of the epidemic transition: Instead of continuous, the response to countermeasures becomes discontinuous. Rather than following the conventional exponential growth, the outbreak that is initially strongly suppressed eventually accelerates and scales faster than exponential during an explosive growth period. As a consequence, containment measures either suffice to stop the outbreak at low total case numbers or fail catastrophically if marginally too weak, thus implying large uncertainties in reliably estimating overall epidemic dynamics, both during initial phases and during second wave scenarios.","lang":"eng"}],"month":"05","intvolume":" 12","scopus_import":"1"},{"article_number":"A17","citation":{"mla":"Marensi, Elena, et al. “Suppression of Turbulence and Travelling Waves in a Vertical Heated Pipe.” Journal of Fluid Mechanics, vol. 919, A17, Cambridge University Press, 2021, doi:10.1017/jfm.2021.371.","ama":"Marensi E, He S, Willis AP. Suppression of turbulence and travelling waves in a vertical heated pipe. Journal of Fluid Mechanics. 2021;919. doi:10.1017/jfm.2021.371","apa":"Marensi, E., He, S., & Willis, A. P. (2021). Suppression of turbulence and travelling waves in a vertical heated pipe. Journal of Fluid Mechanics. Cambridge University Press. https://doi.org/10.1017/jfm.2021.371","short":"E. Marensi, S. He, A.P. Willis, Journal of Fluid Mechanics 919 (2021).","ieee":"E. Marensi, S. He, and A. P. Willis, “Suppression of turbulence and travelling waves in a vertical heated pipe,” Journal of Fluid Mechanics, vol. 919. Cambridge University Press, 2021.","chicago":"Marensi, Elena, Shuisheng He, and Ashley P. Willis. “Suppression of Turbulence and Travelling Waves in a Vertical Heated Pipe.” Journal of Fluid Mechanics. Cambridge University Press, 2021. https://doi.org/10.1017/jfm.2021.371.","ista":"Marensi E, He S, Willis AP. 2021. Suppression of turbulence and travelling waves in a vertical heated pipe. Journal of Fluid Mechanics. 919, A17."},"user_id":"4359f0d1-fa6c-11eb-b949-802e58b17ae8","article_processing_charge":"Yes (via OA deal)","external_id":{"isi":["000653785000001"],"arxiv":["2008.13486"]},"author":[{"full_name":"Marensi, Elena","last_name":"Marensi","id":"0BE7553A-1004-11EA-B805-18983DDC885E","first_name":"Elena"},{"full_name":"He, Shuisheng","last_name":"He","first_name":"Shuisheng"},{"last_name":"Willis","full_name":"Willis, Ashley P.","first_name":"Ashley P."}],"title":"Suppression of turbulence and travelling waves in a vertical heated pipe","acknowledgement":"The anonymous referees are kindly acknowledged for their useful suggestions andcomments.","oa":1,"publisher":"Cambridge University Press","quality_controlled":"1","year":"2021","has_accepted_license":"1","isi":1,"publication":"Journal of Fluid Mechanics","day":"25","date_created":"2021-06-06T22:01:30Z","date_published":"2021-07-25T00:00:00Z","doi":"10.1017/jfm.2021.371","_id":"9467","tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)"},"article_type":"original","type":"journal_article","status":"public","date_updated":"2023-08-08T13:58:41Z","ddc":["530"],"file_date_updated":"2021-08-03T09:53:28Z","department":[{"_id":"BjHo"}],"abstract":[{"lang":"eng","text":"Turbulence in the flow of fluid through a pipe can be suppressed by buoyancy forces. As the suppression of turbulence leads to severe heat transfer deterioration, this is an important and undesirable phenomenon in both heating and cooling applications. Vertical flow is often considered, as the axial buoyancy force can help drive the flow. With heating measured by the buoyancy parameter 𝐶, our direct numerical simulations show that shear-driven turbulence may either be completely laminarised or it transitions to a relatively quiescent convection-driven state. Buoyancy forces cause a flattening of the base flow profile, which in isothermal pipe flow has recently been linked to complete suppression of turbulence (Kühnen et al., Nat. Phys., vol. 14, 2018, pp. 386–390), and the flattened laminar base profile has enhanced nonlinear stability (Marensi et al., J. Fluid Mech., vol. 863, 2019, pp. 50–875). In agreement with these findings, the nonlinear lower-branch travelling-wave solution analysed here, which is believed to mediate transition to turbulence in isothermal pipe flow, is shown to be suppressed by buoyancy. A linear instability of the laminar base flow is responsible for the appearance of the relatively quiescent convection driven state for 𝐶≳4 across the range of Reynolds numbers considered. In the suppression of turbulence, however, i.e. in the transition from turbulence, we find clearer association with the analysis of He et al. (J. Fluid Mech., vol. 809, 2016, pp. 31–71) than with the above dynamical systems approach, which describes better the transition to turbulence. The laminarisation criterion He et al. propose, based on an apparent Reynolds number of the flow as measured by its driving pressure gradient, is found to capture the critical 𝐶=𝐶𝑐𝑟(𝑅𝑒) above which the flow will be laminarised or switch to the convection-driven type. Our analysis suggests that it is the weakened rolls, rather than the streaks, which appear to be critical for laminarisation."}],"oa_version":"Published Version","scopus_import":"1","intvolume":" 919","month":"07","publication_status":"published","publication_identifier":{"eissn":["14697645"],"issn":["00221120"]},"language":[{"iso":"eng"}],"file":[{"creator":"kschuh","date_updated":"2021-08-03T09:53:28Z","file_size":4087358,"date_created":"2021-08-03T09:53:28Z","file_name":"2021_JournalFluidMechanics_Marensi.pdf","access_level":"open_access","relation":"main_file","content_type":"application/pdf","checksum":"867ad077e45c181c2c5ec1311ba27c41","file_id":"9766","success":1}],"volume":919},{"day":"18","publication":"Physical Review Letters","isi":1,"year":"2021","doi":"10.1103/PhysRevLett.126.244502","date_published":"2021-06-18T00:00:00Z","date_created":"2021-06-16T15:45:36Z","acknowledgement":"We thank the referees for improving this Letter with their comments. We acknowledge stimulating discussions with\r\nH. Edelsbrunner. This work was supported by Grant No. 662960 from the Simons Foundation (B. H.). The numerical calculations were performed at TUBITAK ULAKBIM High Performance and Grid Computing Center (TRUBA resources) and IST Austria High Performance Computing cluster.","quality_controlled":"1","publisher":"American Physical Society","oa":1,"user_id":"4359f0d1-fa6c-11eb-b949-802e58b17ae8","citation":{"mla":"Yalniz, Gökhan, et al. “Coarse Graining the State Space of a Turbulent Flow Using Periodic Orbits.” Physical Review Letters, vol. 126, no. 24, 244502, American Physical Society, 2021, doi:10.1103/PhysRevLett.126.244502.","apa":"Yalniz, G., Hof, B., & Budanur, N. B. (2021). Coarse graining the state space of a turbulent flow using periodic orbits. Physical Review Letters. American Physical Society. https://doi.org/10.1103/PhysRevLett.126.244502","ama":"Yalniz G, Hof B, Budanur NB. Coarse graining the state space of a turbulent flow using periodic orbits. Physical Review Letters. 2021;126(24). doi:10.1103/PhysRevLett.126.244502","short":"G. Yalniz, B. Hof, N.B. Budanur, Physical Review Letters 126 (2021).","ieee":"G. Yalniz, B. Hof, and N. B. Budanur, “Coarse graining the state space of a turbulent flow using periodic orbits,” Physical Review Letters, vol. 126, no. 24. American Physical Society, 2021.","chicago":"Yalniz, Gökhan, Björn Hof, and Nazmi B Budanur. “Coarse Graining the State Space of a Turbulent Flow Using Periodic Orbits.” Physical Review Letters. American Physical Society, 2021. https://doi.org/10.1103/PhysRevLett.126.244502.","ista":"Yalniz G, Hof B, Budanur NB. 2021. Coarse graining the state space of a turbulent flow using periodic orbits. Physical Review Letters. 126(24), 244502."},"title":"Coarse graining the state space of a turbulent flow using periodic orbits","author":[{"full_name":"Yalniz, Gökhan","orcid":"0000-0002-8490-9312","last_name":"Yalniz","id":"66E74FA2-D8BF-11E9-8249-8DE2E5697425","first_name":"Gökhan"},{"full_name":"Hof, Björn","orcid":"0000-0003-2057-2754","last_name":"Hof","id":"3A374330-F248-11E8-B48F-1D18A9856A87","first_name":"Björn"},{"full_name":"Budanur, Nazmi B","orcid":"0000-0003-0423-5010","last_name":"Budanur","first_name":"Nazmi B","id":"3EA1010E-F248-11E8-B48F-1D18A9856A87"}],"article_processing_charge":"No","external_id":{"isi":["000663310100008"],"arxiv":["2007.02584"]},"article_number":"244502","project":[{"_id":"238598C6-32DE-11EA-91FC-C7463DDC885E","grant_number":"662960","name":"Revisiting the Turbulence Problem Using Statistical Mechanics: Experimental Studies on Transitional and Turbulent Flows"}],"language":[{"iso":"eng"}],"publication_identifier":{"eissn":["1079-7114"],"issn":["0031-9007"]},"publication_status":"published","related_material":{"link":[{"relation":"press_release","url":"https://ist.ac.at/en/news/turbulent-flow-simplified/","description":"News on IST Homepage"}]},"issue":"24","volume":126,"oa_version":"Preprint","acknowledged_ssus":[{"_id":"ScienComp"}],"abstract":[{"text":"We show that turbulent dynamics that arise in simulations of the three-dimensional Navier--Stokes equations in a triply-periodic domain under sinusoidal forcing can be described as transient visits to the neighborhoods of unstable time-periodic solutions. Based on this description, we reduce the original system with more than 10^5 degrees of freedom to a 17-node Markov chain where each node corresponds to the neighborhood of a periodic orbit. The model accurately reproduces long-term averages of the system's observables as weighted sums over the periodic orbits.\r\n","lang":"eng"}],"month":"06","intvolume":" 126","main_file_link":[{"open_access":"1","url":"https://arxiv.org/abs/2007.02584"}],"date_updated":"2023-08-08T14:08:36Z","department":[{"_id":"GradSch"},{"_id":"BjHo"}],"_id":"9558","status":"public","type":"journal_article","article_type":"letter_note"},{"acknowledgement":"L.S., P.G.Z., and A.I.T. thank the financial support of the European Graphene Flagship Project under grant agreements 881603 and EPSRC grant EP/S030751/1. L.S. and A.I.T. thank the European Union’s Horizon 2020 research and innovation programme under ITN Spin-NANO Marie Sklodowska-Curie grant agreement no. 676108. P.G.Z. and A.I.T. thank the European Union’s Horizon 2020 research and innovation programme under ITN 4PHOTON Marie Sklodowska-Curie grant agreement no. 721394. J.C., S.A.M., and R.S. acknowledge funding by EPSRC (EP/P033369 and EP/M013812). C.L.P., A.J.B., A.I.T., and A.M.F. acknowledge funding by EPSRC Programme Grant EP/N031776/1. S.A.M. acknowledges the Lee-Lucas Chair in Physics, the Solar Energies go Hybrid (SolTech) programme, and the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy - EXC 2089/1 - 390776260.","publisher":"Springer Nature","quality_controlled":"1","oa":1,"day":"18","publication":"Nature Communications","isi":1,"has_accepted_license":"1","year":"2021","doi":"10.1038/s41467-021-26262-3","date_published":"2021-10-18T00:00:00Z","date_created":"2021-10-31T23:01:30Z","article_number":"6063","user_id":"4359f0d1-fa6c-11eb-b949-802e58b17ae8","citation":{"chicago":"Sortino, Luca, Panaiot G. Zotev, Catherine L. Phillips, Alistair J. Brash, Javier Cambiasso, Elena Marensi, A. Mark Fox, Stefan A. Maier, Riccardo Sapienza, and Alexander I. Tartakovskii. “Bright Single Photon Emitters with Enhanced Quantum Efficiency in a Two-Dimensional Semiconductor Coupled with Dielectric Nano-Antennas.” Nature Communications. Springer Nature, 2021. https://doi.org/10.1038/s41467-021-26262-3.","ista":"Sortino L, Zotev PG, Phillips CL, Brash AJ, Cambiasso J, Marensi E, Fox AM, Maier SA, Sapienza R, Tartakovskii AI. 2021. Bright single photon emitters with enhanced quantum efficiency in a two-dimensional semiconductor coupled with dielectric nano-antennas. Nature Communications. 12, 6063.","mla":"Sortino, Luca, et al. “Bright Single Photon Emitters with Enhanced Quantum Efficiency in a Two-Dimensional Semiconductor Coupled with Dielectric Nano-Antennas.” Nature Communications, vol. 12, 6063, Springer Nature, 2021, doi:10.1038/s41467-021-26262-3.","short":"L. Sortino, P.G. Zotev, C.L. Phillips, A.J. Brash, J. Cambiasso, E. Marensi, A.M. Fox, S.A. Maier, R. Sapienza, A.I. Tartakovskii, Nature Communications 12 (2021).","ieee":"L. Sortino et al., “Bright single photon emitters with enhanced quantum efficiency in a two-dimensional semiconductor coupled with dielectric nano-antennas,” Nature Communications, vol. 12. Springer Nature, 2021.","apa":"Sortino, L., Zotev, P. G., Phillips, C. L., Brash, A. J., Cambiasso, J., Marensi, E., … Tartakovskii, A. I. (2021). Bright single photon emitters with enhanced quantum efficiency in a two-dimensional semiconductor coupled with dielectric nano-antennas. Nature Communications. Springer Nature. https://doi.org/10.1038/s41467-021-26262-3","ama":"Sortino L, Zotev PG, Phillips CL, et al. Bright single photon emitters with enhanced quantum efficiency in a two-dimensional semiconductor coupled with dielectric nano-antennas. Nature Communications. 2021;12. doi:10.1038/s41467-021-26262-3"},"title":"Bright single photon emitters with enhanced quantum efficiency in a two-dimensional semiconductor coupled with dielectric nano-antennas","author":[{"first_name":"Luca","last_name":"Sortino","full_name":"Sortino, Luca"},{"first_name":"Panaiot G.","full_name":"Zotev, Panaiot G.","last_name":"Zotev"},{"full_name":"Phillips, Catherine L.","last_name":"Phillips","first_name":"Catherine L."},{"last_name":"Brash","full_name":"Brash, Alistair J.","first_name":"Alistair J."},{"last_name":"Cambiasso","full_name":"Cambiasso, Javier","first_name":"Javier"},{"first_name":"Elena","id":"0BE7553A-1004-11EA-B805-18983DDC885E","last_name":"Marensi","orcid":"0000-0001-7173-4923","full_name":"Marensi, Elena"},{"first_name":"A. Mark","last_name":"Fox","full_name":"Fox, A. Mark"},{"first_name":"Stefan A.","last_name":"Maier","full_name":"Maier, Stefan A."},{"full_name":"Sapienza, Riccardo","last_name":"Sapienza","first_name":"Riccardo"},{"full_name":"Tartakovskii, Alexander I.","last_name":"Tartakovskii","first_name":"Alexander I."}],"external_id":{"arxiv":["2103.16986"],"isi":["000708601800015"]},"article_processing_charge":"No","oa_version":"Published Version","abstract":[{"text":"Single photon emitters in atomically-thin semiconductors can be deterministically positioned using strain induced by underlying nano-structures. Here, we couple monolayer WSe2 to high-refractive-index gallium phosphide dielectric nano-antennas providing both optical enhancement and monolayer deformation. For single photon emitters formed on such nano-antennas, we find very low (femto-Joule) saturation pulse energies and up to 104 times brighter photoluminescence than in WSe2 placed on low-refractive-index SiO2 pillars. We show that the key to these observations is the increase on average by a factor of 5 of the quantum efficiency of the emitters coupled to the nano-antennas. This further allows us to gain new insights into their photoluminescence dynamics, revealing the roles of the dark exciton reservoir and Auger processes. We also find that the coherence time of such emitters is limited by intrinsic dephasing processes. Our work establishes dielectric nano-antennas as a platform for high-efficiency quantum light generation in monolayer semiconductors.","lang":"eng"}],"month":"10","intvolume":" 12","scopus_import":"1","file":[{"access_level":"open_access","relation":"main_file","content_type":"application/pdf","checksum":"8580d128389860f732028c521cd5949e","file_id":"10212","success":1,"creator":"cchlebak","date_updated":"2021-11-03T11:31:24Z","file_size":1434201,"date_created":"2021-11-03T11:31:24Z","file_name":"2021_NatComm_Sortino.pdf"}],"language":[{"iso":"eng"}],"publication_identifier":{"eissn":["2041-1723"]},"publication_status":"published","volume":12,"_id":"10203","status":"public","article_type":"original","type":"journal_article","tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)"},"ddc":["530"],"date_updated":"2023-08-14T08:12:12Z","file_date_updated":"2021-11-03T11:31:24Z","department":[{"_id":"BjHo"}]},{"volume":118,"issue":"45","publication_status":"published","publication_identifier":{"eissn":["1091-6490"],"issn":["0027-8424"]},"language":[{"iso":"eng"}],"main_file_link":[{"open_access":"1","url":"https://arxiv.org/abs/2103.00023"}],"scopus_import":"1","intvolume":" 118","month":"11","abstract":[{"text":"Turbulence generally arises in shear flows if velocities and hence, inertial forces are sufficiently large. In striking contrast, viscoelastic fluids can exhibit disordered motion even at vanishing inertia. Intermediate between these cases, a state of chaotic motion, “elastoinertial turbulence” (EIT), has been observed in a narrow Reynolds number interval. We here determine the origin of EIT in experiments and show that characteristic EIT structures can be detected across an unexpectedly wide range of parameters. Close to onset, a pattern of chevron-shaped streaks emerges in qualitative agreement with linear and weakly nonlinear theory. However, in experiments, the dynamics remain weakly chaotic, and the instability can be traced to far lower Reynolds numbers than permitted by theory. For increasing inertia, the flow undergoes a transformation to a wall mode composed of inclined near-wall streaks and shear layers. This mode persists to what is known as the “maximum drag reduction limit,” and overall EIT is found to dominate viscoelastic flows across more than three orders of magnitude in Reynolds number.","lang":"eng"}],"oa_version":"Preprint","pmid":1,"department":[{"_id":"BjHo"}],"date_updated":"2023-08-14T11:50:10Z","article_type":"original","type":"journal_article","keyword":["multidisciplinary","elastoinertial turbulence","viscoelastic flows","elastic instability","drag reduction"],"status":"public","_id":"10299","date_created":"2021-11-17T13:24:24Z","date_published":"2021-11-03T00:00:00Z","doi":"10.1073/pnas.2102350118","year":"2021","isi":1,"publication":"Proceedings of the National Academy of Sciences","day":"03","oa":1,"quality_controlled":"1","publisher":"National Academy of Sciences","acknowledgement":"We thank Y. Dubief, R. Kerswell, E. Marensi, V. Shankar, V. Steinberg, and V. Terrapon for discussions and helpful comments. A.V. and B.H. acknowledge funding from the Austrian Science Fund, grant I4188-N30, within the Deutsche Forschungsgemeinschaft research unit FOR 2688.","article_processing_charge":"No","external_id":{"arxiv":["2103.00023"],"pmid":[" 34732570"],"isi":["000720926900019"]},"author":[{"first_name":"George H","id":"448BD5BC-F248-11E8-B48F-1D18A9856A87","last_name":"Choueiri","full_name":"Choueiri, George H"},{"last_name":"Lopez Alonso","full_name":"Lopez Alonso, Jose M","orcid":"0000-0002-0384-2022","id":"40770848-F248-11E8-B48F-1D18A9856A87","first_name":"Jose M"},{"first_name":"Atul","id":"2A2006B2-F248-11E8-B48F-1D18A9856A87","full_name":"Varshney, Atul","orcid":"0000-0002-3072-5999","last_name":"Varshney"},{"full_name":"Sankar, Sarath","last_name":"Sankar","first_name":"Sarath"},{"first_name":"Björn","id":"3A374330-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0003-2057-2754","full_name":"Hof, Björn","last_name":"Hof"}],"title":"Experimental observation of the origin and structure of elastoinertial turbulence","citation":{"ista":"Choueiri GH, Lopez Alonso JM, Varshney A, Sankar S, Hof B. 2021. Experimental observation of the origin and structure of elastoinertial turbulence. Proceedings of the National Academy of Sciences. 118(45), e2102350118.","chicago":"Choueiri, George H, Jose M Lopez Alonso, Atul Varshney, Sarath Sankar, and Björn Hof. “Experimental Observation of the Origin and Structure of Elastoinertial Turbulence.” Proceedings of the National Academy of Sciences. National Academy of Sciences, 2021. https://doi.org/10.1073/pnas.2102350118.","ama":"Choueiri GH, Lopez Alonso JM, Varshney A, Sankar S, Hof B. Experimental observation of the origin and structure of elastoinertial turbulence. Proceedings of the National Academy of Sciences. 2021;118(45). doi:10.1073/pnas.2102350118","apa":"Choueiri, G. H., Lopez Alonso, J. M., Varshney, A., Sankar, S., & Hof, B. (2021). Experimental observation of the origin and structure of elastoinertial turbulence. Proceedings of the National Academy of Sciences. National Academy of Sciences. https://doi.org/10.1073/pnas.2102350118","short":"G.H. Choueiri, J.M. Lopez Alonso, A. Varshney, S. Sankar, B. Hof, Proceedings of the National Academy of Sciences 118 (2021).","ieee":"G. H. Choueiri, J. M. Lopez Alonso, A. Varshney, S. Sankar, and B. Hof, “Experimental observation of the origin and structure of elastoinertial turbulence,” Proceedings of the National Academy of Sciences, vol. 118, no. 45. National Academy of Sciences, 2021.","mla":"Choueiri, George H., et al. “Experimental Observation of the Origin and Structure of Elastoinertial Turbulence.” Proceedings of the National Academy of Sciences, vol. 118, no. 45, e2102350118, National Academy of Sciences, 2021, doi:10.1073/pnas.2102350118."},"user_id":"4359f0d1-fa6c-11eb-b949-802e58b17ae8","project":[{"grant_number":"I04188","name":"Instabilities in pulsating pipe flow of Newtonian and complex fluids","_id":"238B8092-32DE-11EA-91FC-C7463DDC885E","call_identifier":"FWF"}],"article_number":"e2102350118"},{"user_id":"c635000d-4b10-11ee-a964-aac5a93f6ac1","citation":{"mla":"Agrawal, Nishchal. Transition to Turbulence and Drag Reduction in Particle-Laden Pipe Flows. Institute of Science and Technology Austria, 2021, doi:10.15479/at:ista:9728.","short":"N. Agrawal, Transition to Turbulence and Drag Reduction in Particle-Laden Pipe Flows, Institute of Science and Technology Austria, 2021.","ieee":"N. Agrawal, “Transition to turbulence and drag reduction in particle-laden pipe flows,” Institute of Science and Technology Austria, 2021.","apa":"Agrawal, N. (2021). Transition to turbulence and drag reduction in particle-laden pipe flows. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:9728","ama":"Agrawal N. Transition to turbulence and drag reduction in particle-laden pipe flows. 2021. doi:10.15479/at:ista:9728","chicago":"Agrawal, Nishchal. “Transition to Turbulence and Drag Reduction in Particle-Laden Pipe Flows.” Institute of Science and Technology Austria, 2021. https://doi.org/10.15479/at:ista:9728.","ista":"Agrawal N. 2021. Transition to turbulence and drag reduction in particle-laden pipe flows. Institute of Science and Technology Austria."},"title":"Transition to turbulence and drag reduction in particle-laden pipe flows","article_processing_charge":"No","author":[{"id":"469E6004-F248-11E8-B48F-1D18A9856A87","first_name":"Nishchal","full_name":"Agrawal, Nishchal","last_name":"Agrawal"}],"day":"29","year":"2021","has_accepted_license":"1","date_created":"2021-07-27T13:40:30Z","doi":"10.15479/at:ista:9728","date_published":"2021-07-29T00:00:00Z","page":"118","oa":1,"publisher":"Institute of Science and Technology Austria","ddc":["532"],"date_updated":"2024-02-28T13:14:39Z","supervisor":[{"id":"3A374330-F248-11E8-B48F-1D18A9856A87","first_name":"Björn","last_name":"Hof","full_name":"Hof, Björn","orcid":"0000-0003-2057-2754"}],"department":[{"_id":"GradSch"},{"_id":"BjHo"}],"file_date_updated":"2022-07-29T22:30:05Z","_id":"9728","keyword":["Drag Reduction","Transition to Turbulence","Multiphase Flows","particle Laden Flows","Complex Flows","Experiments","Fluid Dynamics"],"status":"public","tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)"},"type":"dissertation","language":[{"iso":"eng"}],"file":[{"file_name":"Transition to Turbulence and Drag Reduction in Particle-Laden Pipe Flows.zip","date_created":"2021-07-28T13:32:02Z","creator":"nagrawal","file_size":22859658,"date_updated":"2022-07-29T22:30:05Z","file_id":"9744","checksum":"77436be3563a90435024307b1b5ee7e8","relation":"source_file","access_level":"closed","embargo_to":"open_access","content_type":"application/x-zip-compressed"},{"file_name":"Transition to Turbulence and Drag Reduction in Particle-Laden Pipe Flows.pdf","date_created":"2021-07-28T13:32:05Z","creator":"nagrawal","file_size":18658048,"date_updated":"2022-07-29T22:30:05Z","embargo":"2022-07-28","file_id":"9745","checksum":"72a891d7daba85445c29b868c22575ed","relation":"main_file","access_level":"open_access","content_type":"application/pdf"}],"degree_awarded":"PhD","publication_status":"published","publication_identifier":{"issn":["2663-337X"]},"related_material":{"record":[{"relation":"part_of_dissertation","id":"6189","status":"public"}]},"oa_version":"Published Version","acknowledged_ssus":[{"_id":"M-Shop"}],"abstract":[{"text":"Most real-world flows are multiphase, yet we know little about them compared to their single-phase counterparts. Multiphase flows are more difficult to investigate as their dynamics occur in large parameter space and involve complex phenomena such as preferential concentration, turbulence modulation, non-Newtonian rheology, etc. Over the last few decades, experiments in particle-laden flows have taken a back seat in favour of ever-improving computational resources. However, computers are still not powerful enough to simulate a real-world fluid with millions of finite-size particles. Experiments are essential not only because they offer a reliable way to investigate real-world multiphase flows but also because they serve to validate numerical studies and steer the research in a relevant direction. In this work, we have experimentally investigated particle-laden flows in pipes, and in particular, examined the effect of particles on the laminar-turbulent transition and the drag scaling in turbulent flows.\r\n\r\nFor particle-laden pipe flows, an earlier study [Matas et al., 2003] reported how the sub-critical (i.e., hysteretic) transition that occurs via localised turbulent structures called puffs is affected by the addition of particles. In this study, in addition to this known transition, we found a super-critical transition to a globally fluctuating state with increasing particle concentration. At the same time, the Newtonian-type transition via puffs is delayed to larger Reynolds numbers. At an even higher concentration, only the globally fluctuating state is found. The dynamics of particle-laden flows are hence determined by two competing instabilities that give rise to three flow regimes: Newtonian-type turbulence at low, a particle-induced globally fluctuating state at high, and a coexistence state at intermediate concentrations.\r\n\r\nThe effect of particles on turbulent drag is ambiguous, with studies reporting drag reduction, no net change, and even drag increase. The ambiguity arises because, in addition to particle concentration, particle shape, size, and density also affect the net drag. Even similar particles might affect the flow dissimilarly in different Reynolds number and concentration ranges. In the present study, we explored a wide range of both Reynolds number and concentration, using spherical as well as cylindrical particles. We found that the spherical particles do not reduce drag while the cylindrical particles are drag-reducing within a specific Reynolds number interval. The interval strongly depends on the particle concentration and the relative size of the pipe and particles. Within this interval, the magnitude of drag reduction reaches a maximum. These drag reduction maxima appear to fall onto a distinct power-law curve irrespective of the pipe diameter and particle concentration, and this curve can be considered as the maximum drag reduction asymptote for a given fibre shape. Such an asymptote is well known for polymeric flows but had not been identified for particle-laden flows prior to this work.","lang":"eng"}],"month":"07","alternative_title":["ISTA Thesis"]},{"publication_status":"published","publication_identifier":{"eissn":["23527110"]},"language":[{"iso":"eng"}],"file":[{"creator":"dernst","date_updated":"2020-07-14T12:47:56Z","file_size":679707,"date_created":"2020-01-27T07:32:46Z","file_name":"2020_SoftwareX_Lopez.pdf","access_level":"open_access","relation":"main_file","content_type":"application/pdf","file_id":"7365","checksum":"2af1a1a3cc33557b345145276f221668"}],"volume":11,"abstract":[{"lang":"eng","text":"We present nsCouette, a highly scalable software tool to solve the Navier–Stokes equations for incompressible fluid flow between differentially heated and independently rotating, concentric cylinders. It is based on a pseudospectral spatial discretization and dynamic time-stepping. It is implemented in modern Fortran with a hybrid MPI-OpenMP parallelization scheme and thus designed to compute turbulent flows at high Reynolds and Rayleigh numbers. An additional GPU implementation (C-CUDA) for intermediate problem sizes and a version for pipe flow (nsPipe) are also provided."}],"oa_version":"Published Version","scopus_import":"1","intvolume":" 11","month":"01","date_updated":"2023-08-17T14:29:59Z","ddc":["000"],"department":[{"_id":"BjHo"}],"file_date_updated":"2020-07-14T12:47:56Z","_id":"7364","tmp":{"short":"CC BY-NC-ND (4.0)","name":"Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)","legal_code_url":"https://creativecommons.org/licenses/by-nc-nd/4.0/legalcode","image":"/images/cc_by_nc_nd.png"},"type":"journal_article","article_type":"original","status":"public","year":"2020","has_accepted_license":"1","isi":1,"publication":"SoftwareX","day":"17","date_created":"2020-01-26T23:00:35Z","date_published":"2020-01-17T00:00:00Z","doi":"10.1016/j.softx.2019.100395","oa":1,"quality_controlled":"1","publisher":"Elsevier","citation":{"chicago":"Lopez Alonso, Jose M, Daniel Feldmann, Markus Rampp, Alberto Vela-Martín, Liang Shi, and Marc Avila. “NsCouette – A High-Performance Code for Direct Numerical Simulations of Turbulent Taylor–Couette Flow.” SoftwareX. Elsevier, 2020. https://doi.org/10.1016/j.softx.2019.100395.","ista":"Lopez Alonso JM, Feldmann D, Rampp M, Vela-Martín A, Shi L, Avila M. 2020. nsCouette – A high-performance code for direct numerical simulations of turbulent Taylor–Couette flow. SoftwareX. 11, 100395.","mla":"Lopez Alonso, Jose M., et al. “NsCouette – A High-Performance Code for Direct Numerical Simulations of Turbulent Taylor–Couette Flow.” SoftwareX, vol. 11, 100395, Elsevier, 2020, doi:10.1016/j.softx.2019.100395.","apa":"Lopez Alonso, J. M., Feldmann, D., Rampp, M., Vela-Martín, A., Shi, L., & Avila, M. (2020). nsCouette – A high-performance code for direct numerical simulations of turbulent Taylor–Couette flow. SoftwareX. Elsevier. https://doi.org/10.1016/j.softx.2019.100395","ama":"Lopez Alonso JM, Feldmann D, Rampp M, Vela-Martín A, Shi L, Avila M. nsCouette – A high-performance code for direct numerical simulations of turbulent Taylor–Couette flow. SoftwareX. 2020;11. doi:10.1016/j.softx.2019.100395","ieee":"J. M. Lopez Alonso, D. Feldmann, M. Rampp, A. Vela-Martín, L. Shi, and M. Avila, “nsCouette – A high-performance code for direct numerical simulations of turbulent Taylor–Couette flow,” SoftwareX, vol. 11. Elsevier, 2020.","short":"J.M. Lopez Alonso, D. Feldmann, M. Rampp, A. Vela-Martín, L. Shi, M. Avila, SoftwareX 11 (2020)."},"user_id":"4359f0d1-fa6c-11eb-b949-802e58b17ae8","article_processing_charge":"No","external_id":{"arxiv":["1908.00587"],"isi":["000552271200011"]},"author":[{"full_name":"Lopez Alonso, Jose M","orcid":"0000-0002-0384-2022","last_name":"Lopez Alonso","id":"40770848-F248-11E8-B48F-1D18A9856A87","first_name":"Jose M"},{"first_name":"Daniel","full_name":"Feldmann, Daniel","last_name":"Feldmann"},{"first_name":"Markus","last_name":"Rampp","full_name":"Rampp, Markus"},{"first_name":"Alberto","full_name":"Vela-Martín, Alberto","last_name":"Vela-Martín"},{"id":"374A3F1A-F248-11E8-B48F-1D18A9856A87","first_name":"Liang","full_name":"Shi, Liang","last_name":"Shi"},{"last_name":"Avila","full_name":"Avila, Marc","first_name":"Marc"}],"title":"nsCouette – A high-performance code for direct numerical simulations of turbulent Taylor–Couette flow","article_number":"100395"},{"oa_version":"Preprint","abstract":[{"lang":"eng","text":"In the past two decades, our understanding of the transition to turbulence in shear flows with linearly stable laminar solutions has greatly improved. Regarding the susceptibility of the laminar flow, two concepts have been particularly useful: the edge states and the minimal seeds. In this nonlinear picture of the transition, the basin boundary of turbulence is set by the edge state's stable manifold and this manifold comes closest in energy to the laminar equilibrium at the minimal seed. We begin this paper by presenting numerical experiments in which three-dimensional perturbations are too energetic to trigger turbulence in pipe flow but they do lead to turbulence when their amplitude is reduced. We show that this seemingly counterintuitive observation is in fact consistent with the fully nonlinear description of the transition mediated by the edge state. In order to understand the physical mechanisms behind this process, we measure the turbulent kinetic energy production and dissipation rates as a function of the radial coordinate. Our main observation is that the transition to turbulence relies on the energy amplification away from the wall, as opposed to the turbulence itself, whose energy is predominantly produced near the wall. This observation is further supported by the similar analyses on the minimal seeds and the edge states. Furthermore, we show that the time evolution of production-over-dissipation curves provides a clear distinction between the different initial amplification stages of the transition to turbulence from the minimal seed."}],"intvolume":" 5","month":"02","main_file_link":[{"url":"https://arxiv.org/abs/1912.09270","open_access":"1"}],"scopus_import":"1","language":[{"iso":"eng"}],"publication_status":"published","publication_identifier":{"issn":["2469-990X"]},"volume":5,"issue":"2","_id":"7534","status":"public","type":"journal_article","article_type":"original","date_updated":"2023-08-18T06:44:46Z","department":[{"_id":"BjHo"}],"oa":1,"quality_controlled":"1","publisher":"American Physical Society","publication":"Physical Review Fluids","day":"21","year":"2020","isi":1,"date_created":"2020-02-27T10:26:57Z","date_published":"2020-02-21T00:00:00Z","doi":"10.1103/physrevfluids.5.023903","article_number":"023903","user_id":"4359f0d1-fa6c-11eb-b949-802e58b17ae8","citation":{"ista":"Budanur NB, Marensi E, Willis AP, Hof B. 2020. Upper edge of chaos and the energetics of transition in pipe flow. Physical Review Fluids. 5(2), 023903.","chicago":"Budanur, Nazmi B, Elena Marensi, Ashley P. Willis, and Björn Hof. “Upper Edge of Chaos and the Energetics of Transition in Pipe Flow.” Physical Review Fluids. American Physical Society, 2020. https://doi.org/10.1103/physrevfluids.5.023903.","ama":"Budanur NB, Marensi E, Willis AP, Hof B. Upper edge of chaos and the energetics of transition in pipe flow. Physical Review Fluids. 2020;5(2). doi:10.1103/physrevfluids.5.023903","apa":"Budanur, N. B., Marensi, E., Willis, A. P., & Hof, B. (2020). Upper edge of chaos and the energetics of transition in pipe flow. Physical Review Fluids. American Physical Society. https://doi.org/10.1103/physrevfluids.5.023903","ieee":"N. B. Budanur, E. Marensi, A. P. Willis, and B. Hof, “Upper edge of chaos and the energetics of transition in pipe flow,” Physical Review Fluids, vol. 5, no. 2. American Physical Society, 2020.","short":"N.B. Budanur, E. Marensi, A.P. Willis, B. Hof, Physical Review Fluids 5 (2020).","mla":"Budanur, Nazmi B., et al. “Upper Edge of Chaos and the Energetics of Transition in Pipe Flow.” Physical Review Fluids, vol. 5, no. 2, 023903, American Physical Society, 2020, doi:10.1103/physrevfluids.5.023903."},"title":"Upper edge of chaos and the energetics of transition in pipe flow","external_id":{"isi":["000515065100001"],"arxiv":["1912.09270"]},"article_processing_charge":"No","author":[{"orcid":"0000-0003-0423-5010","full_name":"Budanur, Nazmi B","last_name":"Budanur","first_name":"Nazmi B","id":"3EA1010E-F248-11E8-B48F-1D18A9856A87"},{"last_name":"Marensi","full_name":"Marensi, Elena","first_name":"Elena"},{"first_name":"Ashley P.","last_name":"Willis","full_name":"Willis, Ashley P."},{"orcid":"0000-0003-2057-2754","full_name":"Hof, Björn","last_name":"Hof","id":"3A374330-F248-11E8-B48F-1D18A9856A87","first_name":"Björn"}]},{"date_updated":"2023-08-18T06:47:16Z","department":[{"_id":"BjHo"}],"_id":"7563","status":"public","article_type":"original","type":"journal_article","language":[{"iso":"eng"}],"publication_identifier":{"issn":["1054-1500"],"eissn":["1089-7682"]},"publication_status":"published","issue":"3","volume":30,"oa_version":"Published Version","abstract":[{"lang":"eng","text":"We introduce “state space persistence analysis” for deducing the symbolic dynamics of time series data obtained from high-dimensional chaotic attractors. To this end, we adapt a topological data analysis technique known as persistent homology for the characterization of state space projections of chaotic trajectories and periodic orbits. By comparing the shapes along a chaotic trajectory to those of the periodic orbits, state space persistence analysis quantifies the shape similarity of chaotic trajectory segments and periodic orbits. We demonstrate the method by applying it to the three-dimensional Rössler system and a 30-dimensional discretization of the Kuramoto–Sivashinsky partial differential equation in (1+1) dimensions.\r\nOne way of studying chaotic attractors systematically is through their symbolic dynamics, in which one partitions the state space into qualitatively different regions and assigns a symbol to each such region.1–3 This yields a “coarse-grained” state space of the system, which can then be reduced to a Markov chain encoding all possible transitions between the states of the system. While it is possible to obtain the symbolic dynamics of low-dimensional chaotic systems with standard tools such as Poincaré maps, when applied to high-dimensional systems such as turbulent flows, these tools alone are not sufficient to determine symbolic dynamics.4,5 In this paper, we develop “state space persistence analysis” and demonstrate that it can be utilized to infer the symbolic dynamics in very high-dimensional settings."}],"month":"03","intvolume":" 30","scopus_import":"1","main_file_link":[{"open_access":"1","url":"https://doi.org/10.1063/1.5122969"}],"user_id":"4359f0d1-fa6c-11eb-b949-802e58b17ae8","citation":{"chicago":"Yalniz, Gökhan, and Nazmi B Budanur. “Inferring Symbolic Dynamics of Chaotic Flows from Persistence.” Chaos. AIP Publishing, 2020. https://doi.org/10.1063/1.5122969.","ista":"Yalniz G, Budanur NB. 2020. Inferring symbolic dynamics of chaotic flows from persistence. Chaos. 30(3), 033109.","mla":"Yalniz, Gökhan, and Nazmi B. Budanur. “Inferring Symbolic Dynamics of Chaotic Flows from Persistence.” Chaos, vol. 30, no. 3, 033109, AIP Publishing, 2020, doi:10.1063/1.5122969.","apa":"Yalniz, G., & Budanur, N. B. (2020). Inferring symbolic dynamics of chaotic flows from persistence. Chaos. AIP Publishing. https://doi.org/10.1063/1.5122969","ama":"Yalniz G, Budanur NB. Inferring symbolic dynamics of chaotic flows from persistence. Chaos. 2020;30(3). doi:10.1063/1.5122969","ieee":"G. Yalniz and N. B. Budanur, “Inferring symbolic dynamics of chaotic flows from persistence,” Chaos, vol. 30, no. 3. AIP Publishing, 2020.","short":"G. Yalniz, N.B. Budanur, Chaos 30 (2020)."},"title":"Inferring symbolic dynamics of chaotic flows from persistence","author":[{"orcid":"0000-0002-8490-9312","full_name":"Yalniz, Gökhan","last_name":"Yalniz","id":"66E74FA2-D8BF-11E9-8249-8DE2E5697425","first_name":"Gökhan"},{"last_name":"Budanur","orcid":"0000-0003-0423-5010","full_name":"Budanur, Nazmi B","first_name":"Nazmi B","id":"3EA1010E-F248-11E8-B48F-1D18A9856A87"}],"external_id":{"arxiv":["1910.04584"],"isi":["000519254800002"]},"article_processing_charge":"No","article_number":"033109","day":"03","publication":"Chaos","isi":1,"year":"2020","doi":"10.1063/1.5122969","date_published":"2020-03-03T00:00:00Z","date_created":"2020-03-04T08:06:25Z","quality_controlled":"1","publisher":"AIP Publishing","oa":1},{"type":"journal_article","article_type":"original","tmp":{"name":"Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)","image":"/images/cc_by_nc_sa.png","legal_code_url":"https://creativecommons.org/licenses/by-nc-sa/4.0/legalcode","short":"CC BY-NC-SA (4.0)"},"status":"public","_id":"8043","file_date_updated":"2020-07-14T12:48:08Z","department":[{"_id":"BjHo"}],"date_updated":"2023-08-22T07:48:02Z","ddc":["530"],"scopus_import":"1","month":"08","intvolume":" 897","abstract":[{"text":"With decreasing Reynolds number, Re, turbulence in channel flow becomes spatio-temporally intermittent and self-organises into solitary stripes oblique to the mean flow direction. We report here the existence of localised nonlinear travelling wave solutions of the Navier–Stokes equations possessing this obliqueness property. Such solutions are identified numerically using edge tracking coupled with arclength continuation. All solutions emerge in saddle-node bifurcations at values of Re lower than the non-localised solutions. Relative periodic orbit solutions bifurcating from branches of travelling waves have also been computed. A complete parametric study is performed, including their stability, the investigation of their large-scale flow, and the robustness to changes of the numerical domain.","lang":"eng"}],"oa_version":"Published Version","volume":897,"license":"https://creativecommons.org/licenses/by-nc-sa/4.0/","publication_identifier":{"issn":["00221120"],"eissn":["14697645"]},"publication_status":"published","file":[{"file_size":767873,"date_updated":"2020-07-14T12:48:08Z","creator":"cziletti","file_name":"2020_JournalOfFluidMech_Paranjape.pdf","date_created":"2020-06-30T08:37:37Z","content_type":"application/pdf","relation":"main_file","access_level":"open_access","checksum":"3f487bf6d9286787096306eaa18702e8","file_id":"8070"}],"language":[{"iso":"eng"}],"article_number":"A7","author":[{"last_name":"Paranjape","full_name":"Paranjape, Chaitanya S","first_name":"Chaitanya S","id":"3D85B7C4-F248-11E8-B48F-1D18A9856A87"},{"first_name":"Yohann","full_name":"Duguet, Yohann","last_name":"Duguet"},{"id":"3A374330-F248-11E8-B48F-1D18A9856A87","first_name":"Björn","last_name":"Hof","full_name":"Hof, Björn","orcid":"0000-0003-2057-2754"}],"external_id":{"isi":["000539132300001"]},"article_processing_charge":"Yes (via OA deal)","title":"Oblique stripe solutions of channel flow","citation":{"chicago":"Paranjape, Chaitanya S, Yohann Duguet, and Björn Hof. “Oblique Stripe Solutions of Channel Flow.” Journal of Fluid Mechanics. Cambridge University Press, 2020. https://doi.org/10.1017/jfm.2020.322.","ista":"Paranjape CS, Duguet Y, Hof B. 2020. Oblique stripe solutions of channel flow. Journal of Fluid Mechanics. 897, A7.","mla":"Paranjape, Chaitanya S., et al. “Oblique Stripe Solutions of Channel Flow.” Journal of Fluid Mechanics, vol. 897, A7, Cambridge University Press, 2020, doi:10.1017/jfm.2020.322.","apa":"Paranjape, C. S., Duguet, Y., & Hof, B. (2020). Oblique stripe solutions of channel flow. Journal of Fluid Mechanics. Cambridge University Press. https://doi.org/10.1017/jfm.2020.322","ama":"Paranjape CS, Duguet Y, Hof B. Oblique stripe solutions of channel flow. Journal of Fluid Mechanics. 2020;897. doi:10.1017/jfm.2020.322","ieee":"C. S. Paranjape, Y. Duguet, and B. Hof, “Oblique stripe solutions of channel flow,” Journal of Fluid Mechanics, vol. 897. Cambridge University Press, 2020.","short":"C.S. Paranjape, Y. Duguet, B. Hof, Journal of Fluid Mechanics 897 (2020)."},"user_id":"4359f0d1-fa6c-11eb-b949-802e58b17ae8","publisher":"Cambridge University Press","quality_controlled":"1","oa":1,"acknowledgement":"The authors thank S. Zammert and B. Budanur for useful discussions. J. F. Gibson is gratefully acknowledged for the development and the maintenance of the code Channelflow. Y.D. would like to thank P. Schlatter and D. S. Henningson for an early collaboration on a similar topic in the case of plane Couette flow during the years 2008–2013.","doi":"10.1017/jfm.2020.322","date_published":"2020-08-25T00:00:00Z","date_created":"2020-06-29T07:59:35Z","has_accepted_license":"1","isi":1,"year":"2020","day":"25","publication":"Journal of Fluid Mechanics"},{"publisher":"American Physical Society","quality_controlled":"1","oa":1,"acknowledgement":"M. F. S. and R. O. G. acknowledge funding from the National Science Foundation (CMMI-1234436, DMS1125302, CMMI-1725587) and Defense Advanced Research Projects Agency (HR0011-16-2-0033). B. S.has received funding from the People Programme (Marie Curie Actions) of the European Union's Seventh Framework Programme FP7/2007–2013/ under REA Grant Agreement No. 291734.","date_published":"2020-08-05T00:00:00Z","doi":"10.1103/physrevlett.125.064501","date_created":"2020-10-08T17:27:32Z","isi":1,"year":"2020","day":"05","publication":"Physical Review Letters","project":[{"call_identifier":"FP7","_id":"25681D80-B435-11E9-9278-68D0E5697425","name":"International IST Postdoc Fellowship Programme","grant_number":"291734"}],"article_number":"064501","author":[{"last_name":"Suri","full_name":"Suri, Balachandra","id":"47A5E706-F248-11E8-B48F-1D18A9856A87","first_name":"Balachandra"},{"first_name":"Logan","full_name":"Kageorge, Logan","last_name":"Kageorge"},{"full_name":"Grigoriev, Roman O.","last_name":"Grigoriev","first_name":"Roman O."},{"full_name":"Schatz, Michael F.","last_name":"Schatz","first_name":"Michael F."}],"article_processing_charge":"No","external_id":{"arxiv":["2008.02367"],"isi":["000555785600005"]},"title":"Capturing turbulent dynamics and statistics in experiments with unstable periodic orbits","citation":{"ista":"Suri B, Kageorge L, Grigoriev RO, Schatz MF. 2020. Capturing turbulent dynamics and statistics in experiments with unstable periodic orbits. Physical Review Letters. 125(6), 064501.","chicago":"Suri, Balachandra, Logan Kageorge, Roman O. Grigoriev, and Michael F. Schatz. “Capturing Turbulent Dynamics and Statistics in Experiments with Unstable Periodic Orbits.” Physical Review Letters. American Physical Society, 2020. https://doi.org/10.1103/physrevlett.125.064501.","short":"B. Suri, L. Kageorge, R.O. Grigoriev, M.F. Schatz, Physical Review Letters 125 (2020).","ieee":"B. Suri, L. Kageorge, R. O. Grigoriev, and M. F. Schatz, “Capturing turbulent dynamics and statistics in experiments with unstable periodic orbits,” Physical Review Letters, vol. 125, no. 6. American Physical Society, 2020.","apa":"Suri, B., Kageorge, L., Grigoriev, R. O., & Schatz, M. F. (2020). Capturing turbulent dynamics and statistics in experiments with unstable periodic orbits. Physical Review Letters. American Physical Society. https://doi.org/10.1103/physrevlett.125.064501","ama":"Suri B, Kageorge L, Grigoriev RO, Schatz MF. Capturing turbulent dynamics and statistics in experiments with unstable periodic orbits. Physical Review Letters. 2020;125(6). doi:10.1103/physrevlett.125.064501","mla":"Suri, Balachandra, et al. “Capturing Turbulent Dynamics and Statistics in Experiments with Unstable Periodic Orbits.” Physical Review Letters, vol. 125, no. 6, 064501, American Physical Society, 2020, doi:10.1103/physrevlett.125.064501."},"user_id":"c635000d-4b10-11ee-a964-aac5a93f6ac1","main_file_link":[{"open_access":"1","url":"https://arxiv.org/abs/2008.02367"}],"month":"08","intvolume":" 125","abstract":[{"lang":"eng","text":"In laboratory studies and numerical simulations, we observe clear signatures of unstable time-periodic solutions in a moderately turbulent quasi-two-dimensional flow. We validate the dynamical relevance of such solutions by demonstrating that turbulent flows in both experiment and numerics transiently display time-periodic dynamics when they shadow unstable periodic orbits (UPOs). We show that UPOs we computed are also statistically significant, with turbulent flows spending a sizable fraction of the total time near these solutions. As a result, the average rates of energy input and dissipation for the turbulent flow and frequently visited UPOs differ only by a few percent."}],"oa_version":"Preprint","volume":125,"issue":"6","ec_funded":1,"publication_identifier":{"issn":["0031-9007"],"eissn":["1079-7114"]},"publication_status":"published","language":[{"iso":"eng"}],"type":"journal_article","article_type":"original","status":"public","keyword":["General Physics and Astronomy"],"_id":"8634","department":[{"_id":"BjHo"}],"date_updated":"2023-09-05T12:08:29Z"},{"department":[{"_id":"BjHo"}],"date_updated":"2023-11-30T10:55:13Z","status":"public","type":"journal_article","article_type":"original","_id":"7932","issue":"21","volume":117,"related_material":{"record":[{"id":"12726","status":"public","relation":"dissertation_contains"},{"relation":"dissertation_contains","status":"public","id":"14530"}],"link":[{"url":"https://ist.ac.at/en/news/blood-flows-more-turbulent-than-previously-expected/","relation":"press_release","description":"News on IST Homepage"}]},"ec_funded":1,"language":[{"iso":"eng"}],"publication_identifier":{"issn":["00278424"],"eissn":["10916490"]},"publication_status":"published","month":"05","intvolume":" 117","scopus_import":"1","main_file_link":[{"url":"https://arxiv.org/abs/2005.11190","open_access":"1"}],"oa_version":"Preprint","abstract":[{"lang":"eng","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."}],"title":"Nonlinear hydrodynamic instability and turbulence in pulsatile flow","author":[{"full_name":"Xu, Duo","last_name":"Xu","id":"3454D55E-F248-11E8-B48F-1D18A9856A87","first_name":"Duo"},{"first_name":"Atul","id":"2A2006B2-F248-11E8-B48F-1D18A9856A87","last_name":"Varshney","full_name":"Varshney, Atul","orcid":"0000-0002-3072-5999"},{"id":"34BADBA6-F248-11E8-B48F-1D18A9856A87","first_name":"Xingyu","full_name":"Ma, Xingyu","orcid":"0000-0002-0179-9737","last_name":"Ma"},{"last_name":"Song","full_name":"Song, Baofang","first_name":"Baofang"},{"orcid":"0000-0003-4844-6311","full_name":"Riedl, Michael","last_name":"Riedl","first_name":"Michael","id":"3BE60946-F248-11E8-B48F-1D18A9856A87"},{"last_name":"Avila","full_name":"Avila, Marc","first_name":"Marc"},{"first_name":"Björn","id":"3A374330-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0003-2057-2754","full_name":"Hof, Björn","last_name":"Hof"}],"article_processing_charge":"No","external_id":{"isi":["000536797100014"],"arxiv":["2005.11190"]},"user_id":"4359f0d1-fa6c-11eb-b949-802e58b17ae8","citation":{"ama":"Xu D, Varshney A, Ma X, et al. Nonlinear hydrodynamic instability and turbulence in pulsatile flow. Proceedings of the National Academy of Sciences of the United States of America. 2020;117(21):11233-11239. doi:10.1073/pnas.1913716117","apa":"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. National Academy of Sciences. https://doi.org/10.1073/pnas.1913716117","ieee":"D. Xu et al., “Nonlinear hydrodynamic instability and turbulence in pulsatile flow,” Proceedings of the National Academy of Sciences of the United States of America, vol. 117, no. 21. National Academy of Sciences, pp. 11233–11239, 2020.","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.","mla":"Xu, Duo, et al. “Nonlinear Hydrodynamic Instability and Turbulence in Pulsatile Flow.” Proceedings of the National Academy of Sciences of the United States of America, vol. 117, no. 21, National Academy of Sciences, 2020, pp. 11233–39, doi:10.1073/pnas.1913716117.","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.","chicago":"Xu, Duo, Atul Varshney, Xingyu Ma, Baofang Song, Michael Riedl, Marc Avila, and Björn Hof. “Nonlinear Hydrodynamic Instability and Turbulence in Pulsatile Flow.” Proceedings of the National Academy of Sciences of the United States of America. National Academy of Sciences, 2020. https://doi.org/10.1073/pnas.1913716117."},"project":[{"name":"Instabilities in pulsating pipe flow of Newtonian and complex fluids","grant_number":"I04188","_id":"238B8092-32DE-11EA-91FC-C7463DDC885E","call_identifier":"FWF"},{"_id":"260C2330-B435-11E9-9278-68D0E5697425","call_identifier":"H2020","name":"ISTplus - Postdoctoral Fellowships","grant_number":"754411"}],"date_published":"2020-05-26T00:00:00Z","doi":"10.1073/pnas.1913716117","date_created":"2020-06-07T22:00:51Z","page":"11233-11239","day":"26","publication":"Proceedings of the National Academy of Sciences of the United States of America","isi":1,"year":"2020","quality_controlled":"1","publisher":"National Academy of Sciences","oa":1},{"ec_funded":1,"related_material":{"record":[{"status":"public","id":"6228","relation":"part_of_dissertation"},{"status":"public","id":"6486","relation":"part_of_dissertation"},{"id":"461","status":"public","relation":"part_of_dissertation"},{"id":"422","status":"public","relation":"part_of_dissertation"}]},"degree_awarded":"PhD","publication_status":"published","publication_identifier":{"issn":["2663-337X"]},"language":[{"iso":"eng"}],"file":[{"content_type":"application/zip","embargo_to":"open_access","access_level":"closed","relation":"source_file","checksum":"4df1ab24e9896635106adde5a54615bf","file_id":"7259","date_updated":"2021-01-13T23:30:05Z","file_size":26640830,"creator":"dscarsel","date_created":"2020-01-12T15:57:14Z","file_name":"2020_Scarselli_Thesis.zip"},{"date_created":"2020-01-12T15:56:14Z","file_name":"2020_Scarselli_Thesis.pdf","creator":"dscarsel","date_updated":"2021-01-13T23:30:05Z","file_size":8515844,"file_id":"7260","checksum":"48659ab98e3414293c7a721385c2fd1c","embargo":"2021-01-12","access_level":"open_access","relation":"main_file","content_type":"application/pdf"}],"alternative_title":["ISTA Thesis"],"month":"01","abstract":[{"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.","lang":"eng"}],"oa_version":"None","file_date_updated":"2021-01-13T23:30:05Z","department":[{"_id":"BjHo"}],"date_updated":"2023-09-15T12:20:08Z","supervisor":[{"last_name":"Hof","orcid":"0000-0003-2057-2754","full_name":"Hof, Björn","id":"3A374330-F248-11E8-B48F-1D18A9856A87","first_name":"Björn"}],"ddc":["532"],"type":"dissertation","status":"public","_id":"7258","page":"174","date_created":"2020-01-12T16:07:26Z","date_published":"2020-01-13T00:00:00Z","doi":"10.15479/AT:ISTA:7258","year":"2020","has_accepted_license":"1","day":"13","oa":1,"publisher":"Institute of Science and Technology Austria","article_processing_charge":"No","author":[{"id":"40315C30-F248-11E8-B48F-1D18A9856A87","first_name":"Davide","last_name":"Scarselli","orcid":"0000-0001-5227-4271","full_name":"Scarselli, Davide"}],"title":"New approaches to reduce friction in turbulent pipe flow","citation":{"ama":"Scarselli D. New approaches to reduce friction in turbulent pipe flow. 2020. doi:10.15479/AT:ISTA:7258","apa":"Scarselli, D. (2020). New approaches to reduce friction in turbulent pipe flow. Institute of Science and Technology Austria. https://doi.org/10.15479/AT:ISTA:7258","ieee":"D. Scarselli, “New approaches to reduce friction in turbulent pipe flow,” Institute of Science and Technology Austria, 2020.","short":"D. Scarselli, New Approaches to Reduce Friction in Turbulent Pipe Flow, Institute of Science and Technology Austria, 2020.","mla":"Scarselli, Davide. New Approaches to Reduce Friction in Turbulent Pipe Flow. Institute of Science and Technology Austria, 2020, doi:10.15479/AT:ISTA:7258.","ista":"Scarselli D. 2020. New approaches to reduce friction in turbulent pipe flow. Institute of Science and Technology Austria.","chicago":"Scarselli, Davide. “New Approaches to Reduce Friction in Turbulent Pipe Flow.” Institute of Science and Technology Austria, 2020. https://doi.org/10.15479/AT:ISTA:7258."},"user_id":"c635000d-4b10-11ee-a964-aac5a93f6ac1","project":[{"_id":"25152F3A-B435-11E9-9278-68D0E5697425","call_identifier":"FP7","name":"Decoding the complexity of turbulence at its origin","grant_number":"306589"},{"grant_number":"737549","name":"Eliminating turbulence in oil pipelines","call_identifier":"H2020","_id":"25104D44-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","_id":"25136C54-B435-11E9-9278-68D0E5697425"}]},{"day":"09","has_accepted_license":"1","year":"2020","doi":"10.15479/AT:ISTA:8350","date_published":"2020-09-09T00:00:00Z","date_created":"2020-09-09T11:12:10Z","page":"107","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.","publisher":"Institute of Science and Technology Austria","oa":1,"user_id":"c635000d-4b10-11ee-a964-aac5a93f6ac1","citation":{"mla":"Shamipour, Shayan. Bulk Actin Dynamics Drive Phase Segregation in Zebrafish Oocytes . Institute of Science and Technology Austria, 2020, doi:10.15479/AT:ISTA:8350.","short":"S. Shamipour, Bulk Actin Dynamics Drive Phase Segregation in Zebrafish Oocytes , Institute of Science and Technology Austria, 2020.","ieee":"S. Shamipour, “Bulk actin dynamics drive phase segregation in zebrafish oocytes ,” Institute of Science and Technology Austria, 2020.","apa":"Shamipour, S. (2020). Bulk actin dynamics drive phase segregation in zebrafish oocytes . Institute of Science and Technology Austria. https://doi.org/10.15479/AT:ISTA:8350","ama":"Shamipour S. Bulk actin dynamics drive phase segregation in zebrafish oocytes . 2020. doi:10.15479/AT:ISTA:8350","chicago":"Shamipour, Shayan. “Bulk Actin Dynamics Drive Phase Segregation in Zebrafish Oocytes .” Institute of Science and Technology Austria, 2020. https://doi.org/10.15479/AT:ISTA:8350.","ista":"Shamipour S. 2020. Bulk actin dynamics drive phase segregation in zebrafish oocytes . Institute of Science and Technology Austria."},"title":"Bulk actin dynamics drive phase segregation in zebrafish oocytes ","author":[{"last_name":"Shamipour","full_name":"Shamipour, Shayan","id":"40B34FE2-F248-11E8-B48F-1D18A9856A87","first_name":"Shayan"}],"article_processing_charge":"No","file":[{"checksum":"6e47871c74f85008b9876112eb3fcfa1","file_id":"8351","embargo_to":"open_access","content_type":"application/vnd.openxmlformats-officedocument.wordprocessingml.document","relation":"source_file","access_level":"closed","file_name":"Shayan-Thesis-Final.docx","date_created":"2020-09-09T11:06:27Z","file_size":65194814,"date_updated":"2021-09-11T22:30:05Z","creator":"sshamip"},{"date_created":"2020-09-09T11:06:13Z","file_name":"Shayan-Thesis-Final.pdf","date_updated":"2021-09-11T22:30:05Z","file_size":23729605,"creator":"sshamip","file_id":"8352","checksum":"1b44c57f04d7e8a6fe41b1c9c55a52a3","embargo":"2021-09-10","content_type":"application/pdf","access_level":"open_access","relation":"main_file"}],"language":[{"iso":"eng"}],"publication_identifier":{"issn":["2663-337X"]},"publication_status":"published","degree_awarded":"PhD","related_material":{"record":[{"relation":"part_of_dissertation","status":"public","id":"661"},{"status":"public","id":"6508","relation":"part_of_dissertation"},{"id":"7001","status":"public","relation":"part_of_dissertation"},{"id":"735","status":"public","relation":"part_of_dissertation"}]},"oa_version":"None","acknowledged_ssus":[{"_id":"PreCl"},{"_id":"Bio"},{"_id":"EM-Fac"}],"abstract":[{"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.","lang":"eng"}],"month":"09","alternative_title":["ISTA Thesis"],"ddc":["570"],"supervisor":[{"last_name":"Heisenberg","full_name":"Heisenberg, Carl-Philipp J","orcid":"0000-0002-0912-4566","first_name":"Carl-Philipp J","id":"39427864-F248-11E8-B48F-1D18A9856A87"},{"first_name":"Björn","id":"3A374330-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0003-2057-2754","full_name":"Hof, Björn","last_name":"Hof"}],"date_updated":"2023-09-27T14:16:45Z","file_date_updated":"2021-09-11T22:30:05Z","department":[{"_id":"BjHo"},{"_id":"CaHe"}],"_id":"8350","status":"public","type":"dissertation"}]