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Numerical Simulation of Separated Flows in Channels

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Journal of Thermal Science 2012年第2期21卷 145-153页

作者： Petr Louda jarom.r príhoda Petr Sváek Karel Kozel Czech Technical University in prague Fac. of Mechanical Engineering Karlovo nám. 13 CZ-121 35 Praha 2 Institute of Thermomechanics AS Cr v.v.i. Dolejkova 5 CZ-182 00 Praha 8

The work deals with numerical modelling of turbulent flows in channels with an expansion of the cross-section where flow separation and reattachment occur. The performance of several eddy viscosity models and an explicit algebraic reynolds stress model (EArSM) is studied. The used test cases are flows in channels with various backward facing steps where the step is perpendicular or inclined and the top wall is parallel or deflected. Furthermore, a channel with the circular ramp is considered. The numerical solution is achieved by the finite volume method or by the finite element method. The results of both numerical approaches are compared.

关键词： backward facing step flow EArSM model SST model

Study on the Numerical Model of Transonic Wind Tunnel Test Section

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Journal of Thermal Science 2021年第1期30卷 231-241页

作者： LOUDA Petr PŘÍhoda jarom.r Institute of Thermomechanics of the Czech Academy of Sciences Prague 818200Czech Republic Faculty of Mechanical Engineering Czech Technical UniversityPrague 212135Czech Republic

The authors consider numerical simulations of transonic flows through various turbine cascades in a confined channel which approximates boundaries of real wind *** boundaries of the wind tunnel are impermeable or there can be permeable tailboards to diminish shock wave *** mathematical model is based on Favre-averaged Navier-Stokes equations closed by a turbulence model and model of transition to *** mathematical model is solved by an implicit finite volume method with multi-block *** types of turbine blade cascades with subsonic or supersonic inlet are *** results are compared with optical measurements and simulations of periodic *** validity of experimental reference flow parameters in relation to computed flow patterns is discussed.

关键词： perforated wall model transonic wind tunnel turbine blade cascade

Investigation of the Compressible Flow through the Tip-Section Turbine Blade Cascade with Supersonic Inlet

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Journal of Thermal Science 2016年第2期25卷 138-144页

作者： Martin Luxa jarom.r príhoda David Simurda Petr Straka Jaroslav Synác Institute of Thermomechanics AS Cr v.v.i. Dolejskova 1402/5 18200 Prague Czech Republic Aerospace research and Test Establishment Plc Beranovych 130 19905 Prague Czech Republic Doosan Skoda Power Co. Ltd. Tylova 1/57 30128 Pilsen Czech Republic

The contribution deals with the experimental and numerical investigation of compressible flow through the tip-section turbine blade cascade with the blade 54″ long. Experimental investigations by means of optical(interferometry and schlieren method) and pneumatic measurements provide more information about the behaviour and nature of basic phenomena occurring in the profile cascade flow field. The numerical simulation was carried out by means of the EArSM turbulence model according to Hellsten [5] completed by the bypass transition model with the algebraic equation for the intermittency coefficient proposed by Straka and P?íhoda [6] and implemented into the in-house numerical code. The investigation was focused particularly on the effect of shock waves on the shear layer development including the laminar/turbulent transition. Interactions of shock waves with shear layers on both sides of the blade result usually in the transition in attached and/ or separated flow and so to the considerable impact to the flow structure and energy losses in the blade cascade.

关键词： long turbine rotor blade supersonic tip section optical methods transition modelling CFD

Numerical Simulation of Airfoil Vibrations Induced by Turbulent Flow

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Communications in Computational Physics 2015年第1期17卷 146-188页

作者： Miloslav Feistauer jarom.r Horacek Petr Svacek Charles University in prague Faculty of Mathematics and PhysicsSokolovska 8318675 Praha 8Czech Republic Institute of Thermomechanics Academy of Sciences of the Czech RepublicDolejskova 518200 Praha 8Czech Republic Czech Technical University prague Faculty of Mechanical EngineeringKarlovo nam.1312135 Praha 2Czech Republic

The subject of the paper is the numerical simulation of the interaction of two-dimensional incompressible viscous flow and a vibrating airfoil with large *** airfoil with three degrees of freedom performs rotation around an elastic axis,oscillations in the vertical direction and rotation of a *** numerical simulation consists of the finite element solution of the reynolds averaged Navier-Stokes equations combined with Spalart-Allmaras or k−ω turbulence models,coupled with a system of nonlinear ordinary differential equations describing the airfoil motion with consideration of large *** time-dependent computational domain and approximation on a moving grid are treated by the Arbitrary Lagrangian-Eulerian formulation of the flow *** to large values of the involved reynolds numbers an application of a suitable stabilization of the finite element discretization is *** developed method is used for the computation of flow-induced oscillations of the airfoil near the flutter instability,when the displacements of the airfoil are large,up to±40 degrees in *** paper contains the comparison of the numerical results obtained by both turbulence models.

关键词： Fluid-structure interaction flow induced vibrations reynolds averaged NavierStokes equations turbulence models finite element method coupling algorithm

Lead isotope evolution of the Central European upper mantle:Constraints from the Bohemian Massif

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Geoscience Frontiers 2020年第3期11卷 925-942页

作者： Simona Krmíckova Lukas Krmícek rolf L.romer jarom.r Ulrych Department of Geological Sciences Faculty of ScienceMasaryk UniversityKotlarska 2CZ-61137BrnoCzech Republic Institute of Geology of the Czech Academy of Sciences Rozvojova 269CZ-16502Prague 6Czech Republic Brno University of Technology Faculty of Civil EngineeringAdMaS CentreVeverí95CZ-60200BrnoCzech Republic Deutsches GeoForschungsZentrum GFZ TelegrafenbergD-14473PotsdamGermany

The Pb isotope composition of the upper mantle beneath Central Europe is heterogeneous due to the subduction of regionally contrasting material during the Variscan and Alpine *** Variscan to Cenozoic mantlederived melts allow mapping this heterogeneity on a regional scale for the last ca.340 *** Cretaceous and Cenozoic anorogenic magmatic rocks of the Bohemian Massif(lamprophyres,volcanic rocks of basanite/tephrite and trachyte/phonolite series) concentrate mostly in the Eger *** ultramafic lamprophyres yielded the most radiogenic Pb isotope signatures reflecting a maximum contribution from metasomatised lithospheric mantle,whereas Tertiary alkaline lamprophyres originated from mantle with less radiogenic ^(206)Pb/^(204)b ratios suggesting a more substantial modification of lithospheric source by interaction with asthenosphericderived *** volcanic rocks of the basanite/tephrite and trachyte/phonolite series define a linear mixing trend between these components,indicating dilution of the initial lithospheric mantle signature by upwelling asthenosphere during *** Pb isotope composition of Late Cretaceous and Cenozoic magmatic rocks of the Bohemian Massif follows the same Pb growth curve as Variscan orogenic lamprophyres and lamproites that formed during the collision between Laurussia,Gondwana,and associated *** implies that the crustal Pb signature in the post-Variscan mantle is repeatedly sampled by younger anorogenic *** Cenozoic mantle-derived rocks of Central Europe show similar Pb isotope ranges as the Bohemian Massif.

关键词： Lead isotopes Lamprophyres Volcanic rocks Mantle components Bohemian massif Variscan orogeny

Acquired haemophilia as a complicating factor in treatment of nonmuscle invasive bladder cancer:A case report

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World Journal of Clinical Cases 2023年第22期11卷 5338-5343页

作者： Kateřina ryšánková jarom.r Gumulec Michal Grepl Jan Krhut Department of Urology University Hospital OstravaOstrava 70852Czech Republic Department of Surgical Studies Faculty of MedicineOstrava UniversityOstrava 70300Czech Republic Department of Haematooncology University Hospital OstravaOstrava 70852Czech Republic Department of Internal Medicine Faculty of MedicineOstrava UniversityOstrava 70300Czech Republic

BACKGrOUND Acquired haemophilia(AH)is a serious autoimmune haematological disease caused by the production of auto-antibodies against coagulation factor *** some patients,AH is associated with a concomitant *** case of surgical intervention,AH poses a high risk of life-threatening *** SUMMArY A 60-year-old female patient with multiple recurrences of non-muscle invasive bladder cancer underwent transurethral tumour resection.A severe haematuria developed postoperatively warranting two endoscopic revisions;however,no clear source of bleeding was identified in the *** haematological examination established a diagnosis of *** with factor VIII inhibitor bypass activity and immunosuppressive therapy was initiated *** patient responded well to the therapy and was discharged from the hospital 21 d after the primary *** the 38-mo follow-up,both AH and bladder cancer remained in complete *** AH is a rare,life-threatening haematological *** should be considered in patients with persistent severe haematuria or other bleeding symptoms,especially if combined with isolated activated partial thromboplastin time prolongation.

关键词： Acquired haemophilia A Bladder cancer Bleeding Complication Surgery Case report

Ion emission from warm dense matter produced by irradiation with a soft x-ray free-electron laser

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Matter and radiation at Extremes 2024年第1期9卷 71-84页

作者： Josef Krása Tomás Burian Vera Hájková jarom.r Chalupský Šimon Jelínek Katerina Frantálová Michal Krupka Zuzana Kuglerová Sushil Kumar Singh Vojtech Vozda Ludek Vysín MichalŠmíd Pablo Perez-Martin Marion Kühlman Juan Pintor Jakub Cikhardt Matthias Dreimann Dennis Eckermann Felix rosenthal Sam M.Vinko Alessandro Forte Thomas Gawne Thomas Campbell Shenyuan ren YuanFeng Shi Trevor Hutchinson Oliver Humphries Thomas preston Mikako Makita Motoaki Nakatsutsumi Xiayun Pan Alexander Köhler Marion Harmand Sven Toleikis Katerina Falk Libor Juha Department of radiation and Chemical Physics Institute of PhysicsCzech Academy of SciencesNa Slovance 218221 Prague 8Czech Republic Laser Plasma Department Institute of Plasma PhysicsCzech Academy of SciencesZa Slovankou 318200 Prague 8Czech Republic Department of Surface and Plasma Science Faculty of Mathematics and PhysicsCharles University in PragueV Holesovi ckách 218000 Prague 8Czech Republic Department of Physical Electronics Faculty of Nuclear Science and Engineering PhysicsCzech Technical University in PragueV Holesovi ckách 218000 Prague 8Czech Republic Helmholtz-Zentrum Dresden-rossendorf Bautzner Landstraße 40001328 DresdenGermany DESY Photon Science Notkestraße 85D-22607 HamburgGermany Institut de Minéralogie de Physique des Matériaux et de CosmochimieUMR 7590–UPMC/CNRS/IRD/MNHNSorbonne Université4 place Jussieu75005 ParisFrance Department of Physics Faculty of Electrical EngineeringCzech Technical University in PragueTechnická216627 Prague 6Czech Republic Center for Soft Nanoscience University of MünsterBusso-Peus-Straße 10D-48149 MünsterGermany Department of Physics Clarendon LaboratoryUniversity of OxfordParks RoadOxford OX13PUUnited Kingdom Central Laser Facility STFC Rutherford Appleton LaboratoryDidcot OX110QXUnited Kingdom Lawrence Livermore National Laboratory 7000 East AvenueLivermoreCalifornia 94550USA European XFEL GmbH Holzkoppel 4D-22869 SchenefeldGermany Technische Universität Dresden 01062 DresdenGermany

We report on an experiment performed at the FLASH2 free-electron laser(FEL)aimed at producing warm dense matter via soft x-ray isochoric *** the experiment,we focus on study of the ions emitted during the soft x-ray ablation process using time-of-flight electron multipliers and a shifted Maxwell–Boltzmann velocity distribution *** find that most emitted ions are thermal,but that some impurities chemisorbed on the target surface,such as protons,are accelerated by the electrostatic field created in the plasma by escaped *** morphology of the complex crater structure indicates the presence of several ion groups with varying *** find that the ion sound velocity is controlled by the ion temperature and show how the ion yield depends on the FEL radiation attenuation length in different materials.

关键词： electrostatic emitted chemi

Significance of postoperative follow-up of patients with metastatic colorectal cancer using circulating tumor DNA

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World Journal of Gastroenterology 2019年第48期25卷 6939-6948页

作者： Lucie Benešová Tereza Hálková renata Ptáčková Anastasiya Semyakina Kateřina Menclová JiříPudil Miroslav ryska Miroslav Levý jarom.rŠimša Filip Pazdírek JiříHoch Milan Blaha Marek Minárik Centre for Applied Genomics of Solid Tumors Genomac Research InstitutePrague CZ 16100Czech Republic Surgery Department 2nd Faculty of Medicine of Charles University Prague and Military University HospitalPrague CZ 16902Czech Republic Surgery Department 1st Faculty of MedicineCharles University Prague and Thomayer HospitalPrague CZ 14059Czech Republic Surgery Department 2nd Faculty of Medicine of Charles University Prague and Motol University HospitalPrague CZ 15006Czech Republic Institute of Biostatistics and Analyses of the Masaryk University Brno CZ 62500Czech Republic Elphogene Prague CZ 16100Czech Republic

BACKGrOUND One of the most notable applications for circulating tumor DNA(ctDNA)detection in peripheral blood of patients with metastatic colorectal cancer(mCrC)is a long-term postoperative *** referred to as a“liquid(re)biopsy”it is a minimally invasive procedure and can be performed repeatedly at relatively short intervals(months or even weeks).The presence of the disease and the actual extent of the tumor burden(tumor mass)within the patient’s body can be *** is of particular importance,especially when evaluating radicality of surgical treatment as well as for early detection of disease progression or *** To confirm the radicality of surgery using ctDNA and compare available methods for detection of recurrence in metastatic colorectal *** total of 47 patients with detected ctDNA and indications for resection of mCrC were enrolled in the multicenter study involving three surgical *** postoperative follow-ups using imaging techniques and the determination of tumor markers were supplemented by ctDNA *** addition to the baseline ctDNA testing prior to surgery,a postoperative observation was conducted by evaluating ctDNA presence up to a week after surgery and subsequently at approximately three-month *** presence of ctDNA was correlated with radicality of surgical treatment and the actual clinical status of the *** Among the monitored patients,the r0(curative)resection correlated with postoperative ctDNA negativity in 26 out of 28 cases of surgical procedures(26/28,93%).In the remaining cases of r0 surgeries that displayed ctDNA,both patients were diagnosed with a recurrence of the disease after 6 *** 7 patients who underwent an r1 resection,4 ctDNA positivities(4/7,57%)were detected after surgery and associated with the confirmation of early disease recurrence(after 3 to 7 months).All 15 patients(15/15,100%)undergoing r2 resection remained constantly ctDNA positive dur

关键词： Circulating tumor DNA Metastatic colorectal cancer Postoperative radicality of resection Follow-up recurrence

Azathioprine does not reduce adenoma formation in a mouse model of sporadic intestinal tumorigenesis

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World Journal of Gastroenterology 2014年第44期20卷 16683-16689页

作者： Mattheus CB Wielenga Jooske F van Lidth de Jeude Sanne L rosekrans Alon D Levin Monique Schukking Geert rAM D'Haens jarom Heijmans Marnix Jansen Vanesa Muncan Gijs r van den Brink Tytgat Institute for Liver and Intestinal research and Department of Gastroenterology and Hepatology Academic Medical Center Department of Pathology Academic Medical Center

AIM: To investigate if azathioprine could reduce adenoma formation in ApcMin/+, a mouse model of sporadic intestinal tumorigenesis.

关键词： Azathioprine Thiopurine Intestinal adenoma Polyp ApcMin Chemoprevention Lymphoma Colon cancer