1,685 research outputs found

    The multiple ionospheric probe Auroral ionospheric report

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    Multiple impedance and resonance probe payload for ionospheric property observation in Nike- Apache rocke

    A Glance to the Fragmenta Membranea Manuscript Collection Through Ftir and Radiocarbon Analyses

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    The Fragmenta membranea manuscript fragment collection at the National Library of Finland has proved challenging to date using only traditional paleography. Therefore, radiocarbon dates can contribute to the understanding of these fragments by offering a parallel natural scientific timeline for the parchment the manuscripts are written on. In this study, we apply our previously developed method for radiocarbon dating medieval manuscripts made of parchment. In total 35 datings were made from 14 separate assemblages of manuscripts, being the first systematic wide-scale application of radiocarbon dating to a collection of medieval manuscripts in order to improve their chronological proxy. Additionally, due to the fragmentary and sometimes poor condition of the manuscript fragments of Fragmenta membranea analyzed in this study, we used Fourier-transform infrared spectroscopy (FTIR) to evaluate the quality of the collagen and the presence of contaminants in the fragments affecting the radiocarbon dates. We report out radiocarbon dating results and FTIR screenings for each sample and for each manuscript assemblage, and discuss the applicability of our method in further studies of applying radiocarbon dating on objects of cultural historical interest and value. The results indicate an essential role of high-quality samples and multiple measurements to interpret the radiocarbon dating results.Peer reviewe

    Resection margins and local recurrences of impalpable breast cancer : Comparison between radioguided occult lesion localization (ROLL) and radioactive seed localization (RSL)

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    Objectives: The aim of this retrospective study is to compare surgical margins, reoperation rates and local recurrences after breast conserving surgery (BCS) using radioguided occult lesion localization (ROLL) or radioactive seed localization (RSL). Materials and methods: We reviewed 744 consecutive patients with impalpable primary invasive breast cancer who underwent BCS at Helsinki University Hospital between 2010 and 2012. ROLL was used in our unit until October 31st, 2011; from November 1st we changed localization method to RSL. Results: 318 patients underwent ROLL and 426 RSL. Patients in the RSL group had more often multifocal (p = 0.013) tumours. No statistically significant differences were found regarding tumour size, specimen weight, histology or grade of tumours or lymph node status. 42 (5.6%) patients were reoperated because of insufficient margins, 13 (4.1%) in the ROLL group and 29 (6.8%) in the RSL group. The reoperation rate was not different between the groups either in the univariable analysis (p = 0.112) or in the multivariable binary logistic regression analysis (p = 0.204). Risk factors for reoperations were multifocality of the tumour (p Conclusion: Reoperation rates and LRFS were comparable for ROLL and RSL in patients with impalpable breast cancer treated with BCS. (C) 2019 Elsevier Ltd. All rights reserved.Peer reviewe

    Temperature dependence of the Brewer global UV measurements

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    Spectral measurements of global UV irradiance recorded by Brewer spectrophotometers can be significantly affected by instrument-specific optical and mechanical features. Thus, proper corrections are needed in order to reduce the associated uncertainties to within acceptable levels. The present study aims to contribute to the reduction of uncertainties originating from changes in the Brewer internal temperature, which affect the performance of the optical and electronic parts, and subsequently the response of the instrument. Until now, measurements of the irradiance from various types of lamps at different temperatures have been used to characterize the instruments' temperature dependence. The use of 50 W lamps was found to induce errors in the characterization due to changes in the transmissivity of the Teflon diffuser as it warms up by the heat of the lamp. In contrast, the use of 200 or 1000 W lamps is considered more appropriate because they are positioned at longer distances from the diffuser so that warming is negligible. Temperature gradients inside the instrument can cause mechanical stresses which can affect the instrument's optical characteristics. Therefore, during the temperature-dependence characterization procedure warming or cooling must be slow enough to minimize these effects. In this study, results of the temperature characterization of eight different Brewer spectrophotometers operating in Greece, Finland, Germany and Spain are presented. It was found that the instruments' response changes differently in different temperature regions due to different responses of the diffusers' transmittance. The temperature correction factors derived for the Brewer spectrophotometers operating at Thessaloniki, Greece, and Sodankylä, Finland, were evaluated and were found to remove the temperature dependence of the instruments' sensitivity.This article is based upon work from COST Action ES1207 “A European Brewer Network (EUBREWNET)”, supported by COST (European Cooperation in Science and Technology) and from the ENV59-ATMOZ (“Traceability for atmospheric total column ozone”) Joint Research Programme (JRP)

    Evidence of Josephson-coupled superconducting regions at the interfaces of Highly Oriented Pyrolytic Graphite

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    Transport properties of a few hundreds of nanometers thick (in the graphene plane direction) lamellae of highly oriented pyrolytic graphite (HOPG) have been investigated. Current-Voltage characteristics as well as the temperature dependence of the voltage at different fixed input currents provide evidence for Josephson-coupled superconducting regions embedded in the internal two-dimensional interfaces, reaching zero resistance at low enough temperatures. The overall behavior indicates the existence of superconducting regions with critical temperatures above 100 K at the internal interfaces of oriented pyrolytic graphite.Comment: 6 Figures, 5 page

    The BSUIN project

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    Baltic Sea Underground Innovation Network (BSUIN) is an European Union funded project that extends capabilities of underground laboratories. The aim of the project is to join efforts in making the underground laboratories in the Baltic Sea Region’s more accessible for innovation, business development and science by improving the availability of information about the underground facilities, service offerings, user experience, safety and marketing.The development of standards for the characterization of underground laboratories will allow to compared them with each other. This will help you choose the best places for physical measurements such as neutrino physics or searching for dark matter. The project concerns laboratories where so far no measurements have been made, and even undergrounds where there are no organized laboratories yet.The description of the BSUIN project and the first results of characterization of natural radioactive background in underground laboratories will be presented ˙ The BSUIN Project is funded by Interreg Baltic Sea funding cooperation [2]

    Search for Low-Mass Quark-Antiquark Resonances Produced in Association with a Photon at root s=13 TeV

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    A search for narrow low-mass resonances decaying to quark-antiquark pairs is presented. The search is based on proton-proton collision events collected at 13 TeV by the CMS detector at the CERN LHC. The data sample corresponds to an integrated luminosity of 35.9 fb(-1), recorded in 2016. The search considers the case where the resonance has high transverse momentum due to initial-state radiation of a hard photon. To study this process, the decay products of the resonance are reconstructed as a single large-radius jet with two-pronged substructure. The signal would be identified as a localized excess in the jet invariant mass spectrum. No evidence for such a resonance is observed in the mass range 10 to 125 GeV. Upper limits at the 95% confidence level are set on the coupling strength of resonances decaying to quark pairs. The results obtained with this photon trigger strategy provide the first direct constraints on quark-antiquark resonance masses below 50 GeV obtained at a hadron collider.Peer reviewe

    Search for lepton flavour violating decays of a neutral heavy Higgs boson to mu tau and e tau in proton-proton collisions at root s=13 TeV

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    A search for lepton flavour violating decays of a neutral non-standard-model Higgs boson in the mu tau and e tau decay modes is presented. The search is based on proton-proton collisions at a center of mass energy root s = 13 TeV collected with the CMS detector in 2016, corresponding to an integrated luminosity of 35.9 fb(-1). The tau leptons are reconstructed in the leptonic and hadronic decay modes. No signal is observed in the mass range 200-900 GeV. At 95% confidence level, the observed (expected) upper limits on the production cross section multiplied by the branching fraction vary from 51.9 (57.4) fb to 1.6 (2.1) fb for the mu tau and from 94.1 (91.6) fb to 2.3 (2.3) fb for the e tau decay modes.Peer reviewe

    The production of isolated photons in PbPb and pp collisions at root s(NN)=5.02 TeV

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    The transverse energy (ET gamma) spectra of photons isolated from other particles are measured using proton-proton (pp) and lead-lead (PbPb) collisions at the LHC at root s(NN) = 5.02 TeV with integrated luminosities of 27.4 pb(-1) and 404 mu b(-1) for pp and PbPb data, respectively. The results are presented for photons with 25 <E-T(gamma)<200 GeV in the pseudorapidity range vertical bar eta vertical bar <1.44, and for different centrality intervals for PbPb collisions. Photon production in PbPb collisions is consistent with that in pp collisions scaled by the number of binary nucleon-nucleon collisions, demonstrating that photons do not interact with the quark-gluon plasma. Therefore, isolated photons can provide information about the initial energy of the associated parton in photon+jet measurements. The results are compared with predictions from the next-to-leading-order jetphox generator for different parton distribution functions (PDFs) and nuclear PDFs (nPDFs). The comparisons can help to constrain the nPDFs global fits.Peer reviewe
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