1,473 research outputs found

    Nova tehnologija proizvodnje magnezijevih traka i limova

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    A new production technology for magnesium strip, based on twin-roll-casting and strip rolling was developed in Freiberg Germany. By means of this economic method it is possible to produce strips in deep drawing quality with good forming properties in order to satisfy the request for low cost Mg sheets in the automotive and electronic industry. Both, coils as single sheets, were manufactured and rolled to a thickness of 1mm(0,5 mm). The technology of the new process and the properties of the twin-roll-casted material and the final sheets are presented.Nova tehnologija proizvodnje magnezijevih traka i limova. Nova tehnologija proizvodnje magnezijevih traka utemeljena dvostruko-valjanje-lijevanje i valjanje trake je razvijeno u Freibergu-Njemačka. Motri se, ovom ekonomičnom metodom je moguća proizvoditi trake za duboko izvlačenje, sa dobrim plastičnim svojstvima uz zadovoljavajući zahtjev za nisku cijenu Mg trake za automobilsku i elektronsku industriju. Oboje, svitak i pojedinačne trake su poizvedene i valjane do debljine stjenke 1mm(0,5 mm). Prikazuje se tehnologija novog postupka i svojstva dvostrukog valjanog-lijevačkog materijala i završnih traka

    Nova tehnologija proizvodnje magnezijevih traka i limova

    Get PDF
    A new production technology for magnesium strip, based on twin-roll-casting and strip rolling was developed in Freiberg Germany. By means of this economic method it is possible to produce strips in deep drawing quality with good forming properties in order to satisfy the request for low cost Mg sheets in the automotive and electronic industry. Both, coils as single sheets, were manufactured and rolled to a thickness of 1mm(0,5 mm). The technology of the new process and the properties of the twin-roll-casted material and the final sheets are presented.Nova tehnologija proizvodnje magnezijevih traka i limova. Nova tehnologija proizvodnje magnezijevih traka utemeljena dvostruko-valjanje-lijevanje i valjanje trake je razvijeno u Freibergu-Njemačka. Motri se, ovom ekonomičnom metodom je moguća proizvoditi trake za duboko izvlačenje, sa dobrim plastičnim svojstvima uz zadovoljavajući zahtjev za nisku cijenu Mg trake za automobilsku i elektronsku industriju. Oboje, svitak i pojedinačne trake su poizvedene i valjane do debljine stjenke 1mm(0,5 mm). Prikazuje se tehnologija novog postupka i svojstva dvostrukog valjanog-lijevačkog materijala i završnih traka

    Mitochondrial DNA haplotypes indicate two postglacial re-colonization routes of the spruce bark beetle Ips typographus through northern Europe to Scandinavia

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    Species in northern Europe re-colonized the region after the last glacial maximum via several routes, which could have lingering signatures in current intraspecific trait variation. The spruce bark beetle, Ips typographus, occurs across Europe, and biological differences have been found between southern and northern Scandinavian populations. However, the postglacial history of I. typographus in Scandinavia has not been previously studied at a fine geographical scale. Therefore, we collected specimens across northern Europe and analysed the genetic variation in a quite large mitochondrial fragment (698 bp). A high genetic diversity was found in some of the most northern populations, in the Baltic States, Gotland and central Europe. Detected genetic and phylogeographic structures suggest that I. typographus re-colonized Scandinavia via two pathways, one from the northeast and one from the south. These findings are consistent with the re-colonization history of its host plant, Picea abies. However, we observed low haplotype and nucleotide diversity in southern Scandinavian populations of I. typographus, indicating that (unlike P. abies) it did not disperse across the Baltic Sea in multiple events. Further, the divergence among Scandinavian populations was shallow, conflicting with a scenario where I. typographus expanded concurrently with its host plant from a 'cryptic refugium' in the northwest

    Strong Electron-Phonon Coupling in Superconducting MgB2_2: A Specific Heat Study

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    We report on measurements of the specific heat of the recently discovered superconductor MgB2_2 in the temperature range between 3 and 220 K. Based on a modified Debye-Einstein model, we have achieved a rather accurate account of the lattice contribution to the specific heat, which allows us to separate the electronic contribution from the total measured specific heat. From our result for the electronic specific heat, we estimate the electron-phonon coupling constant λ\lambda to be of the order of 2, significantly enhanced compared to common weak-coupling values 0.4\leq 0.4. Our data also indicate that the electronic specific heat in the superconducting state of MgB2_2 can be accounted for by a conventional, s-wave type BCS-model.Comment: 4 pages, 4 figure

    FOXP3 Inhibitory Peptide P60 Increases Efficacy of Cytokine-induced Killer Cells against Renal and Pancreatic Cancer Cells

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    Background/Aim: Cytokine-induced killer (CIK) cells are ex vivo expanded major histocompatibility complex (MHC)-unrestricted cytotoxic cells with promising effects against a variety of cancer types. Regulatory T-cells (T-reg) have been shown to reduce the effectiveness of CIK cells against tumor cells. Peptide P60 has been shown to inhibit the immunosuppressive functions of T-regs. This study aimed at examining the effect of p60 on CIK cells efficacy against renal and pancreatic cancer cells. Materials and Methods: The effect of P60 on CIK cytotoxicity was examined using flow cytometry, WST-8-based cell viability assay and interferon γ (IFNγ) ELISA. Results: P60 treatment resulted in a significant decrease in the viability of renal and pancreatic cancer cell lines co-cultured with CIK cells. No increase in IFNγ secretion from CIK cells was detected following treatment with P60. P60 caused no changes in the distribution of major effector cell populations in CIK cell cultures. Conclusion: P60 may potentiate CIK cell cytotoxicity against tumor cells

    Direct Imaging discovery of a second planet candidate around the possibly transiting planet host CVSO 30

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    We surveyed the 25 Ori association for direct-imaging companions. This association has an age of only few million years. Among other targets, we observed CVSO 30, which has recently been identified as the first T Tauri star found to host a transiting planet candidate. We report on photometric and spectroscopic high-contrast observations with the Very Large Telescope, the Keck telescopes, and the Calar Alto observatory. They reveal a directly imaged planet candidate close to the young M3 star CVSO 30. The JHK-band photometry of the newly identified candidate is at better than 1 sigma consistent with late-type giants, early-T and early-M dwarfs, and free-floating planets. Other hypotheses such as galaxies can be excluded at more than 3.5 sigma. A lucky imaging z' photometric detection limit z'= 20.5 mag excludes early-M dwarfs and results in less than 10 MJup for CVSO 30 c if bound. We present spectroscopic observations of the wide companion that imply that the only remaining explanation for the object is that it is the first very young (Publisher PDFPeer reviewe

    LPMLE3 : a novel 1-D approach to study water flow in streambeds using heat as a tracer

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    We introduce LPMLE3, a new 1-D approach to quantify vertical water flow components at streambeds using temperature data collected in different depths. LPMLE3 solves the partial differential equation for coupled water flow and heat transport in the frequency domain. Unlike other 1-D approaches it does not assume a semi-infinite halfspace with the location of the lower boundary condition approaching infinity. Instead, it uses local upper and lower boundary conditions. As such, the streambed can be divided into finite subdomains bound at the top and bottom by a temperature-time series. Information from a third temperature sensor within each subdomain is then used for parameter estimation. LPMLE3 applies a low order local polynomial to separate periodic and transient parts (including the noise contributions) of a temperature-time series and calculates the frequency response of each subdomain to a known temperature input at the streambed top. A maximum-likelihood estimator is used to estimate the vertical component of water flow, thermal diffusivity, and their uncertainties for each streambed subdomain and provides information regarding model quality. We tested the method on synthetic temperature data generated with the numerical model STRIVE and demonstrate how the vertical flow component can be quantified for field data collected in a Belgian stream. We show that by using the results in additional analyses, nonvertical flow components could be identified and by making certain assumptions they could be quantified for each subdomain. LPMLE3 performed well on both simulated and field data and can be considered a valuable addition to the existing 1-D methods

    The Effect of Shadowing on Initial Conditions, Transverse Energy and Hard Probes in Ultrarelativistic Heavy Ion Collisions

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    The effect of shadowing on the early state of ultrarelativistic heavy ion collisions is investigated along with transverse energy and hard process production, specifically Drell-Yan, J/ψJ/\psi, and Υ\Upsilon production. We choose several parton distributions and parameterizations of nuclear shadowing, as well as the spatial dependence of shadowing, to study the influence of shadowing on relevant observables. Results are presented for Au+Au collisions at sNN=200\sqrt{s_{NN}} = 200 GeV and Pb+Pb collisions at sNN=5.5\sqrt{s_{NN}} = 5.5 TeV.Comment: Submitted to Phys. Rev.

    Heavy-flavour and quarkonium production in the LHC era: from proton-proton to heavy-ion collisions

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    This report reviews the study of open heavy-flavour and quarkonium production in high-energy hadronic collisions, as tools to investigate fundamental aspects of Quantum Chromodynamics, from the proton and nucleus structure at high energy to deconfinement and the properties of the Quark-Gluon Plasma. Emphasis is given to the lessons learnt from LHC Run 1 results, which are reviewed in a global picture with the results from SPS and RHIC at lower energies, as well as to the questions to be addressed in the future. The report covers heavy flavour and quarkonium production in proton-proton, proton-nucleus and nucleus-nucleus collisions. This includes discussion of the effects of hot and cold strongly interacting matter, quarkonium photo-production in nucleus-nucleus collisions and perspectives on the study of heavy flavour and quarkonium with upgrades of existing experiments and new experiments. The report results from the activity of the SaporeGravis network of the I3 Hadron Physics programme of the European Union 7th Framework Programme

    Soft and virtual corrections to pp -> H + X at NNLO

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    The contributions of virtual corrections and soft gluon emission to the inclusive Higgs production cross section pp -> H + X are computed at next-to-next-to-leading order in the heavy top quark limit. We show that this part of the total cross section is well behaved in the sense of perturbative convergence, with the NNLO corrections amounting to an enhancement of the NLO cross section by \sim 5% for LHC and 10-20% for the Tevatron. We compare our results with an existing estimate of the full NNLO effects and argue that an analytic evaluation of the hard scattering contributions is needed.Comment: 16 pages, 7 figures, 16 ps files embedded with epsf. Minor modifications: references and note added, results unchange
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