126 research outputs found

    Review of the Research on the Turbulence in the Laboratory for Thermal Engineering and Energy

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    Paper gives a review of the most important results of turbulence research achieved by the Laboratory for Thermal Engineering and Energy at the Vinca Insitute of Nuclear Sciences. Paper presents detailed overview of the history of the scientific research provided in the laboratory, from the beginning in the mid-60s to today, pointing out the main reasons initiating the investigations in this field. After the first period, which was mainly devoted to the research of the structure of the turbulence, since the beginning of the 80s, research is mainly oriented to the flows at high temperatures including chemical reactions and to the development and improvement of differential mathematical models as a modern and very efficient tool in the technological development. This research significantly contributed to the development of pulverized coal burners, plasma-chemical reactors, and optimization of pulverized coal fired boilers operating parameters and prediction of the greenhouse gases emissions. Most recent period includes experimental and numerical studies of the coherent structures in turbulent fluid jets, mathematical modeling of various turbulent thermal flow processes including two-phase turbulent flow in the multiphase heat exchangers and mathematical modeling of the atmospheric boundary layer.Turbulence Workshop, Aug 31-Sep 02, 2015, Univ Belgrade, Fac Mech Engn, Belgrade, Serbi

    Monocyte activation drives preservation of membrane thiols by promoting release of oxidised membrane moieties via extracellular vesicles

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    This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.The redox state of cellular exofacial molecules is reflected by the amount of available thiols. Furthermore, surface thiols can be considered as indicators of immune cell activation. One group of thiol containing proteins, peroxiredoxins, in particular, have been associated with inflammation. In this study, we assessed surface thiols of the U937 and Thp1 monocyte cell lines and primary monocytes in vitro upon inflammatory stimulation by irreversibly labelling the cells with a fluorescent derivative of maleimide. We also investigated exofacial thiols on circulating blood mononuclear cells in patients with rheumatoid arthritis and healthy controls. When analysing extracellular vesicles, we combined thiol labelling with the use of antibodies to specific CD markers to exclude extracellular vesicle mimicking signals from thiol containing protein aggregates. Furthermore, differential detergent lysis was applied to confirm the vesicular nature of the detected extracellular events in blood plasma. We found an increase in exofacial thiols on monocytes upon in vitro stimulation by LPS or TNF, both in primary monocytes and monocytic cell lines (p<0.0005). At the same time, newly released extracellular vesicles showed a decrease in their exofacial thiols compared with those from unstimulated cells (p<0.05). We also found a significant elevation of surface thiols on circulating monocytes in rheumatoid arthritis patients (p<0.05) and newly released extracellular vesicles of isolated CD14(+) cells from rheumatoid arthritis patients had decreased thiol levels compared with healthy subjects (p<0.01). Exofacial peroxiredoxin 1 was demonstrated on the surface of primary and cultured monocytes, and the number of peroxiredoxin 1 positive extracellular vesicles was increased in rheumatoid arthritis blood plasma (p<0.05). Furthermore, an overoxidised form of peroxiredoxin was detected in extracellular vesicle-enriched preparations from blood plasma. Our data show that cell surface thiols play a protective role and reflect oxidative stress resistance state in activated immune cells. Furthermore, they support a role of extracellular vesicles in the redox regulation of human monocytes, possibly representing an antioxidant mechanism.This work was supported by the National Scientific Research Program of Hungary (OTKA) grant no. PD 104369 to KSZT, grant no. PD 112085 to VVK and grant no. 111958 and 120237 to EIB, the MEDINPROT Program (Synergy programs I, III and IV), BMBS COST Action(BM1202), the János Bolyai Research Fellowship of the Hungarian Academy of Sciences (to KVV) and the Kerpel Fronius Program of the Semmelweis University (Astellas Pharma Grant to BSW)

    Nuclear dependence of the transverse single-spin asymmetry in the production of charged hadrons at forward rapidity in polarized p+pp+p, p+p+Al, and p+p+Au collisions at sNN=200\sqrt{s_{_{NN}}}=200 GeV

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    We report on the nuclear dependence of transverse single-spin asymmetries (TSSAs) in the production of positively-charged hadrons in polarized p+pp^{\uparrow}+p, p+p^{\uparrow}+Al and p+p^{\uparrow}+Au collisions at sNN=200\sqrt{s_{_{NN}}}=200 GeV. The measurements have been performed at forward rapidity (1.4<η<2.41.4<\eta<2.4) over the range of 1.8<pT<7.01.8<p_{T}<7.0 GeV/c/c and 0.1<xF<0.20.1<x_{F}<0.2. We observed a positive asymmetry ANA_{N} for positively-charged hadrons in \polpp collisions, and a significantly reduced asymmetry in pp^{\uparrow}+AA collisions. These results reveal a nuclear dependence of charged hadron ANA_N in a regime where perturbative techniques are relevant. These results provide new opportunities to use \polpA collisions as a tool to investigate the rich phenomena behind TSSAs in hadronic collisions and to use TSSA as a new handle in studying small-system collisions.Comment: 303 authors from 66 institutions, 9 pages, 2 figures, 1 table. v1 is version accepted for publication in Physical Review Letters. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

    Nuclear dependence of the transverse-single-spin asymmetry for forward neutron production in polarized pp++AA collisions at sNN=200\sqrt{s_{_{NN}}}=200 GeV

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    During 2015 the Relativistic Heavy Ion Collider (RHIC) provided collisions of transversely polarized protons with Au and Al nuclei for the first time, enabling the exploration of transverse-single-spin asymmetries with heavy nuclei. Large single-spin asymmetries in very forward neutron production have been previously observed in transversely polarized pp++pp collisions at RHIC, and the existing theoretical framework that was successful in describing the single-spin asymmetry in pp++pp collisions predicts only a moderate atomic-mass-number (AA) dependence. In contrast, the asymmetries observed at RHIC in pp++AA collisions showed a surprisingly strong AA dependence in inclusive forward neutron production. The observed asymmetry in pp++Al collisions is much smaller, while the asymmetry in pp++Au collisions is a factor of three larger in absolute value and of opposite sign. The interplay of different neutron production mechanisms is discussed as a possible explanation of the observed AA dependence.Comment: 315 authors, 8 pages, 4 figures, 1 table. v2 is version accepted for publication in Phys. Rev. Lett. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm
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