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Journal of Thermal Science 2024年第5期33卷 1839-1850页

作者： Jaromír PRIHODA petr STRAKA David SImURDA petr SIDLOF Jan LEPICOVSKY Institute of Thermomechanics of the Czech Academy of Sciences Dolejskova 1402/518200 Prague 5Czech Republic Aerospace Research and Test Centre Beranovych 13019905 PragueCzech Republic Technical University of Liberec Faculty of MechatronicsStudentska 246117 Liberec 1Czech Republic

The paper reports on 3D numerical simulations of unsteady compressible airflow in a blade cascade consisting of flat profiles using a hybrid LES/RANS approach including a transition *** a first step towards simulation of blade flutter in turbomachinery,various incidence angle offsets of the middle blade were *** simulations were run for the flow regime characterized by outlet isentropic mach number m_(is)=0.5and zero *** results of the LES/RANS simulations(pressure and mach number distributions)were compared to a baseline RANS model,and to experimental data measured in a high-speed wind *** numerical results show that both methods overpredict flow separation taking place at the leading *** this regard,the hybrid LES/RANS method does not provide superior results compared to the traditional RANS ***,the LES/RANS results also capture vortex shedding from the blunt trailing *** frequency of the trailing edge vortex shedding in CFD simulations matches perfectly the spectral peak recorded during wind tunnel measurements.

关键词： numerical simulation blade cascade hybrid LES/RANS

Anorectal hemangioma, a rare cause of lower gastrointestinal bleeding, treated with selective embolization: A case report

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World Journal of Gastrointestinal Surgery 2024年第8期16卷 2735-2741页

作者： Barbora Pospisilova Jaromir Frydrych Antonin Krajina JuliusÖrhalmi Ivana m Kajzrlikova petr Vitek Department of Internal medicine Hospital in Frydek-MistekFrydek-Mistek 73801Czech Republic Department of Radiodiagnostic Hospital in Jablonec nad NisouJablonec nad Nisou 46601Czech Republic Department of Radiology University Hospital Hradec KraloveHradec Kralove 50005Czech Republic Department of Surgery Hospital HoroviceHorovice 26831Czech Republic Faculty of medicine University of OstravaOstrava 70300Czech Republic

BACKGROUND Anorectal hemangioma is a rare and frequently misdiagnosed cause of lower gastrointestinal(GI)***,we present a minimally invasive therapy with selective *** SUmmARY A 21-year-old male patient experienced painless rectal bleeding since childhood and was treated for ulcerative *** studies later revealed specific characteristics for vascular lesions-anorectal *** severity of rectal bleeding caused symptomatic anemia and possible surgical treatment was asso-ciated with a high risk of fecal ***,we present selective emboli-zation,a minimally invasive therapeutic approach that is proven as an alternative therapeutic method of *** patient significantly improved temporarily and had a small ischemic ulcer,which healed with a control colonoscopy and deve-loped no *** Awareness of the clinical and radiological features of GI hemangiomas may help improve diagnostics and avoid inappropriate therapeutic procedures.

关键词： Hemangioma Vascular malformation Gastrointestinal hemorrhage Rectal bleeding Phlebolith Selective embolization Case report

Catalytic co-combustion of biomass and brown coal in a fluidized bed:Economic and environmental benefits

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Journal of Environmental Sciences 2024年第6期140卷 24-36页

作者： Yury V.Dubinin Nikolay A.Yazykov petr m.Yeletsky Roman B.Tabakaev Aleksandra I.Belyanovskaya Vadim A.Yakovlev Federal Research Center Boreskov Institute of Catalysis SB RAS Lavrentiev Ave.5Novosibirsk630090Russia University of Tyumen Volodarskogo str.6Tyumen625003Russia

The work is devoted to the study of combustion of brown coal,pine sawdust,and their mixtures in a fluidized bed of catalyst at 600-750℃.It is shown that an increase in the content of sawdust in a mixture with brown coal leads to an increase in the burnout degree of solid fuel from 94.4%to 99.9%,while the emission of greenhouse gases in the form of CO_(2)CO and NOxis reduced(CO_(2)from the biomass is not included in the balance).The high content of alkaline earth metal oxides(CaO and mgO)in the mineral part of brown coal,sawdust,and their mixtures eliminates the emission of sulfur oxides and the slagging of heat-exchange surfaces during the combustion in a fluidized bed of *** optimal temperature,when the highest burnout degree of the above fuels is achieved in the combustion is 750℃.It is also shown that the increase in temperature and the content of sawdust in the composition of the fuel mixtures has a positive effect on the economic and environmental process indicators.

关键词： Co-combustion Fluidized catalyst bed Biomass Coal Economic effect Environmental impact

Effect of sodium nitroprusside on the microrheological properties of red blood cells in di®erent media

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Journal of Innovative Optical Health Sciences 2024年第5期17卷 23-31页

作者： petr Ermolinskiy matvey maksimov Andrei Lugovtsov Alexey muravyov Irina Tikhomirova Alexander Priezzhev Faculty of Physics M.V.Lomonosov Moscow State University Moscow 119991Russia Faculty of Physical Education K.D.Ushinsky Yaroslavl State Pedagogical University Yaroslavl 150000 Russia Faculty of Natural Sciences K.D.Ushinsky Yaroslavl State Pedagogical University Yaroslavl 150000 Russia

Red blood cell(RBC)aggregation as well as their deformation signi¯cantly affects blood *** processes depend on various factors,one of which is concentration of the nitric oxide,one of the main signaling molecule in the *** purpose of this study was to investigate the effect of nitric oxide on the microrheological properties of red blood cells(RBCs)in RBC samples of various media after the addition of nitric oxide donor sodium nitroprusside in *** properties were measured using laser aggregometer and ektacytometer based on diffuse light scattering and diffraction of laser light on a suspension of RBCs,*** study found that heparin-stabilized blood showed increased RBC aggregation and deformation with sodium nitroprusside concentrations of 100,and 200m,while EDTA-stabilized blood showed slightly decreased aggregation and unchanged *** washed RBCs in dextran solution,the addition of sodium nitroprusside(in the concentrations of 100,and 200m)resulted in decreased aggregation and increased ***-ndings aid in our understanding of nitric oxide's effect on RBC microrheological properties.

关键词： Sodium nitroprusside nitric oxide red blood cells RBC aggregation diffuse light scattering laser diffractometer

An integrated microfluidic platform for nucleic acid testing

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microsystems & Nanoengineering 2024年第3期10卷 181-194页

作者： Antao Sun petra Vopařilová Xiaocheng Liu Bingqian Kou TomášŘezníček TomášLednický Sheng Ni JiříKudr Ondřej Zítka Zdenka Fohlerová petr Pajer Haoqing Zhang Pavel Neužil ministry of Education Key Laboratory of micro and Nano Systems for Aerospace School of Mechanical EngineeringNorthwestern Polytechnical University127 West Youyi RoadXi’anShaanxi 710072P.R.China Department of Chemistry and Biochemistry Mendel University in BrnoZemědělská161300 BrnoCzech Republic ITD Tech s.r.o Osvoboditelů100573581 BohumínCzech Republic Central European Institute of Technology Brno University of TechnologyPurkyňova 123Brno 61200Czech Republic Department of Electronic and Computer Engineering The Hong Kong University of Science and TechnologyClear Water BayKowloonHong Kong SARChina Department of microelectronics Faculty of Electrical Engineering and CommunicationBrno University of TechnologyTechnická3058/10Brno 61600Czech Republic military Health Institute U Vojenskénemocnice 120016200 Praha 6Czech Republic The Key Laboratory of Biomedical Information Engineering of ministry of Education School of Life Science and TechnologyXi’an Jiaotong UniversityXi’anShaanxi 710049P.R.China Bioinspired Engineering and Biomechanics Center(BEBC) Xi’an Jiaotong UniversityXi’an 710049P.R.China

This study presents a rapid and versatile low-cost sample-to-answer system for SARS-CoV-2 *** system integrates the extraction and purification of nucleic acids,followed by amplification via either reverse transcriptionquantitative polymerase chain reaction(RT–qPCR)or reverse transcription loop-mediated isothermal amplification(RT–LAmP).By meeting diverse diagnostic and reagent needs,the platform yields testing results that closely align with those of commercial RT-LAmP and RT‒qPCR *** advantages of our system include its speed and *** assay is completed within 28 min,including sample loading(5 min),ribonucleic acid(RNA)extraction(3 min),and RT-LAmP(20 min).The cost of each assay is≈$9.5,and this pricing is competitive against that of Food and Drug Administration(FDA)-approved commercial *** some RNA loss during on-chip extraction is observed,the platform maintains a potential limit of detection lower than 297 *** makes the system particularly useful in environments where centralized laboratories are either unavailable or inconveniently *** key feature is the platform’s versatility,allowing users to choose between RT‒qPCR or RT‒LAmP tests based on specific requirements.

关键词： testing maintain versatile

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 Jaromír 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

Corrosion testing of X52 and X80 steels immersed in stimulated emulsions using a real petroleum sample

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petroleum Research 2024年第2期9卷 304-316页

作者： L.m.Quej-Ake J.L.Alamilla A.Contreras Instituto mexicano del petróleo Eje Central Lázaro CárdenasNorte 152San Bartolo AtepehuacanGustavo A.MaderoCiudad de MéxicoC.P.07730México

The aim of this study is to evaluate the internal corrosion process on X52 and X80 steels/real petroleum interfaces containing condensed hydrocarbon plus oilfield-produced water,which were subjected to stimulated emulsions using 50/50 vol ratio mixtures at 45℃,different hydrodynamic conditions,1 h,and 24 h.A washing process by using deionized water was proposed to simulate and identify the corrosiveness of the hydrocarbon phase after 24 h of exposure *** characterization by electrochemical impedance spectroscopy and the monitoring of the polarization curves indicated that X80 steel/oilfield-produced water interfaces were more susceptible to corrosion than X52 steel exposed to oilfield-produced *** combined speed rotation of 600 rpm using a magnetic stirrer+600 rpm using a rotating disk electrode decreased the corrosion rate on X52 *** stimulated emulsions made of hydrocarbon+oilfield-produced water and hydrocarbon+deionized water at 24 h increased the corrosion rate on X80 steel(0.34 mm/year and 0.43 mm/year,respectively),promoting the formation of erosion and pitting *** types of corrosion depended mainly on the physicochemical properties of the hydrocarbon,oilfield-produced water,exposure times,and hydrodynamic systems in which the hydrocarbon was studied.

关键词： Corrosion Emulsions X52 steel X80 steel

Development tendencies of moulding and core sands

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China Foundry 2011年第4期8卷 438-446页

作者： Stanisaw m.Dobosz petr Jelinek Katarzyna major-Gabry AGH University of Science and Technology Faculty of Foundry Engineering Department of Moulding Materials Mould Technology and Foundry of Non-ferrous Metals al. A.Mickiewicza 30 30-059 Krakow Poland VB–Ostrava University of Technology FmmI Foundry Department Czech Republic

Further development of the technology for making moulding and core sands will be strictly limited by tough requirements due to protection of the natural environment. These tendencies are becoming more and more tense, so that we will reach a point when even processes, that from technological point of view fulfill high requirements of the foundry industry, must be replaced by more ecologically-friendly solutions. Hence, technologies using synthetic resins as binding materials will be limited. This paper presents some predictable development tendencies of moulding and core sands. The increasing role of inorganic substances will be noticed, including silicate binders with significantly improved properties, such as improved knock-out property or higher reclamation strength. Other interesting solutions might also be moulding sands bonded by geo-polymers and phosphate binders or salts and also binders based on degradable biopolymers. These tendencies and the usefulness of these binders are put forward in this paper.

关键词： moulding sand core sand development tendencies

mechanical Properties Optimization metal Bars and Sheets made of 34CrNimo6 Steel

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Journal of Iron and Steel Research International 2011年第S1期18卷 956-960页

作者： Dzugan Jan Novy Zbysek motycka petr martinkova Jana martinek petr COmTES FHT Inc. Prumyslova 995334 41 DobranyCzech Republic

Currently available and well known materials treated by a special procedures can provide superior properties in the comparison to presently obtained *** treatment procedures are efficiently developed with the use of physical simulators *** simulators allow treatment optimization on small scale laboratory samples which can be subsequently transferred to real production processes later ***,there is always need of successful transfer from small scale laboratory experiments to real production of for example metal *** the current paper thermo-mechanical procedure developed for 34CrNimo6 steel under laboratory conditions is applied to metal sheets *** were obtained very promising properties on the bulk material samples processed in the physical simulator,the challenge was to obtain similar properties on a real metal sheets by a transfer of laboratory procedure to metal sheet production *** the considered case the combination of tensile strength and elongation were especially required for considered application in a train *** order to achieve excellent elongation for high strength hardened steel,very fine microstructure has to be attained through the thermo-mechanical process *** good results were achieved on produced metal sheets.6% elongation was attained allowing the possibility of further material processing,*** of sheets,with tensile strength exceeding 1500 *** study presented here confirms usefulness of thermo-mechanical simulators for new procedures *** the use of the simulator of thermaldeformation cycles a materials with optimized properties for certain application can be efficiently developed.

关键词： physical simulation thermo-mechanical treatment