424 research outputs found

    High-index glass for the products of ophthalmologic optics

    Get PDF
    The results of development of high-index glass for the products of ophthalmologic optics on the basis of the systems Li2O – RO – B2O3– SiO2and K2O – TiO2– SiO2are presented. It is shown that the formation of complexes [TiO4/2O] 2– K2 + in glass of the system K2O – TiO2– SiO2interferes with the formation of the chromophorecenters Fe 2+ – O – Ti 4+ and allows to receive colorless glass at amount of TiO2to 30 mol.%. The compositions of glass with a refractive index 1.65 and 1.70 at density no more than 2.91 g/cm 3 are developed. It allows to recommend them for the production of the facilitated lenses with a high optical force

    The effect of intervertebral cartilage on neutral posture and range of motion in the necks of sauropod dinosaurs

    Get PDF
    The necks of sauropod dinosaurs were a key factor in their evolution. The habitual posture and range of motion of these necks has been controversial, and computer-aided studies have argued for an obligatory sub-horizontal pose. However, such studies are compromised by their failure to take into account the important role of intervertebral cartilage. This cartilage takes very different forms in different animals. Mammals and crocodilians have intervertebral discs, while birds have synovial joints in their necks. The form and thickness of cartilage varies significantly even among closely related taxa. We cannot yet tell whether the neck joints of sauropods more closely resembled those of birds or mammals. Inspection of CT scans showed cartilage:bone ratios of 4.5% for Sauroposeidon and about 20% and 15% for two juvenile Apatosaurus individuals. In extant animals, this ratio varied from 2.59% for the rhea to 24% for a juvenile giraffe. It is not yet possible to disentangle ontogenetic and taxonomic signals, but mammal cartilage is generally three times as thick as that of birds. Our most detailed work, on a turkey, yielded a cartilage:bone ratio of 4.56%. Articular cartilage also added 11% to the length of the turkey's zygapophyseal facets. Simple image manipulation suggests that incorporating 4.56% of neck cartilage into an intervertebral joint of a turkey raises neutral posture by 15°. If this were also true of sauropods, the true neutral pose of the neck would be much higher than has been depicted. An additional 11% of zygapophyseal facet length translates to 11% more range of motion at each joint. More precise quantitative results must await detailed modelling. In summary, including cartilage in our models of sauropod necks shows that they were longer, more elevated and more flexible than previously recognised

    ВЛИЯНИЕ ĐœĐžĐ”Đ˜Đ€Đ˜ĐšĐĐąĐžĐ ĐžĐ’ НА РЕОЛОГИЧЕСКИЕ И бЕРМИЧЕСКИЕ СВОЙСбВА Đ‘ĐžĐ ĐžĐĄĐ˜Đ›Đ˜ĐšĐĐąĐĐ«Đ„ СбЕКОЛ

    Get PDF
    Results of research for the glass system Na2O-K2O-B2O3-SiO2 at 2:1 molar ratio of K2O/Na2O modifiers are presented. It has been found that increasing (K2O+Na2O)/B2O3 ratio in glass compositions leads to higher low-temperature viscosity and viscosity gradient in the range of 109-104Pa-s. The established temperature dependences of viscosity allow to optimize borosilicate glass compositions with predetermined characteristics, as well as technological parameters of their synthesis and formation.ĐŸŃ€Đ”ĐŽŃŃ‚Đ°ĐČĐ»Đ”ĐœŃ‹ Ń€Đ”Đ·ŃƒĐ»ŃŒŃ‚Đ°Ń‚Ń‹ ĐžŃŃĐ»Đ”ĐŽĐŸĐČĐ°ĐœĐžŃ стДĐșĐŸĐ» ŃĐžŃŃ‚Đ”ĐŒŃ‹ Na2O-K2O-B2O3-SiO2 про ĐŒĐŸĐ»ŃŃ€ĐœĐŸĐŒ ŃĐŸĐŸŃ‚ĐœĐŸŃˆĐ”ĐœĐžĐž ĐŒĐŸĐŽĐžŃ„ĐžĐșĐ°Ń‚ĐŸŃ€ĐŸĐČ K2O/Na2O, раĐČĐœĐŸĐŒ 2:1. ĐŁŃŃ‚Đ°ĐœĐŸĐČĐ»Đ”ĐœĐŸ, Ń‡Ń‚ĐŸ Ń€ĐŸŃŃ‚ ŃĐŸĐŸŃ‚ĐœĐŸŃˆĐ”ĐœĐžŃ (K2O+Na2O)/B2O3 ĐČ ŃĐŸŃŃ‚Đ°ĐČĐ” стДĐșĐŸĐ» ĐČŃ‹Đ·Ń‹ĐČаДт уĐČĐ”Đ»ĐžŃ‡Đ”ĐœĐžĐ” ĐœĐžĐ·ĐșĐŸŃ‚Đ”ĐŒĐżĐ”Ń€Đ°Ń‚ŃƒŃ€ĐœĐŸĐč ĐČŃĐ·ĐșĐŸŃŃ‚Đž Đž ĐłŃ€Đ°ĐŽĐžĐ”ĐœŃ‚Đ° ĐČŃĐ·ĐșĐŸŃŃ‚Đž ĐČ ĐžĐœŃ‚Đ”Ń€ĐČалД Đ·ĐœĐ°Ń‡Đ”ĐœĐžĐč 109-104 Па-с. ĐŁŃŃ‚Đ°ĐœĐŸĐČĐ»Đ”ĐœĐœŃ‹Đ” Ń‚Đ”ĐŒĐżĐ”Ń€Đ°Ń‚ŃƒŃ€ĐœŃ‹Đ” Đ·Đ°ĐČĐžŃĐžĐŒĐŸŃŃ‚Đž ĐČŃĐ·ĐșĐŸŃŃ‚Đž ĐżĐŸĐ·ĐČĐŸĐ»ŃŃŽŃ‚ ĐŸĐżŃ‚ĐžĐŒĐžĐ·ĐžŃ€ĐŸĐČать ŃĐŸŃŃ‚Đ°ĐČы Đ±ĐŸŃ€ĐŸŃĐžĐ»ĐžĐșĐ°Ń‚ĐœŃ‹Ń… стДĐșĐŸĐ» с Đ·Đ°ĐŽĐ°ĐœĐœŃ‹ĐŒĐž хараĐșтДрОстОĐșĐ°ĐŒĐž, Đ° таĐșжД Ń‚Đ”Ń…ĐœĐŸĐ»ĐŸĐłĐžŃ‡Đ”ŃĐșОД ĐżĐ°Ń€Đ°ĐŒĐ”Ń‚Ń€Ń‹ ох ŃĐžĐœŃ‚Đ”Đ·Đ° Đž Ń„ĐŸŃ€ĐŒĐŸĐČĐ°ĐœĐžŃ

    International Veterinary Epilepsy Task Force Consensus Proposal: Outcome of therapeutic interventions in canine and feline epilepsy

    Get PDF
    Common criteria for the diagnosis of drug resistance and the assessment of outcome are needed urgently as a prerequisite for standardized evaluation and reporting of individual therapeutic responses in canine epilepsy. Thus, we provide a proposal for the definition of drug resistance and partial therapeutic success in canine patients with epilepsy. This consensus statement also suggests a list of factors and aspects of outcome, which should be considered in addition to the impact on seizures. Moreover, these expert recommendations discuss criteria which determine the validity and informative value of a therapeutic trial in an individual patient and also suggest the application of individual outcome criteria. Agreement on common guidelines does not only render a basis for future optimization of individual patient management, but is also a presupposition for the design and implementation of clinical studies with highly standardized inclusion and exclusion criteria. Respective standardization will improve the comparability of findings from different studies and renders an improved basis for multicenter studies. Therefore, this proposal provides an in-depth discussion of the implications of outcome criteria for clinical studies. In particular ethical aspects and the different options for study design and application of individual patient-centered outcome criteria are considered

    Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

    Get PDF
    The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal

    Hunt for new phenomena using large jet multiplicities and missing transverse momentum with ATLAS in 4.7 fb−1 of s√=7TeV proton-proton collisions

    Get PDF
    Results are presented of a search for new particles decaying to large numbers of jets in association with missing transverse momentum, using 4.7 fb−1 of pp collision data at s√=7TeV collected by the ATLAS experiment at the Large Hadron Collider in 2011. The event selection requires missing transverse momentum, no isolated electrons or muons, and from ≄6 to ≄9 jets. No evidence is found for physics beyond the Standard Model. The results are interpreted in the context of a MSUGRA/CMSSM supersymmetric model, where, for large universal scalar mass m 0, gluino masses smaller than 840 GeV are excluded at the 95% confidence level, extending previously published limits. Within a simplified model containing only a gluino octet and a neutralino, gluino masses smaller than 870 GeV are similarly excluded for neutralino masses below 100 GeV

    Measurements of Higgs boson production and couplings in diboson final states with the ATLAS detector at the LHC

    Get PDF
    Measurements are presented of production properties and couplings of the recently discovered Higgs boson using the decays into boson pairs, H →γ Îł, H → Z Z∗ →4l and H →W W∗ →lÎœlÎœ. The results are based on the complete pp collision data sample recorded by the ATLAS experiment at the CERN Large Hadron Collider at centre-of-mass energies of √s = 7 TeV and √s = 8 TeV, corresponding to an integrated luminosity of about 25 fb−1. Evidence for Higgs boson production through vector-boson fusion is reported. Results of combined ïŹts probing Higgs boson couplings to fermions and bosons, as well as anomalous contributions to loop-induced production and decay modes, are presented. All measurements are consistent with expectations for the Standard Model Higgs boson

    Standalone vertex ïŹnding in the ATLAS muon spectrometer

    Get PDF
    A dedicated reconstruction algorithm to find decay vertices in the ATLAS muon spectrometer is presented. The algorithm searches the region just upstream of or inside the muon spectrometer volume for multi-particle vertices that originate from the decay of particles with long decay paths. The performance of the algorithm is evaluated using both a sample of simulated Higgs boson events, in which the Higgs boson decays to long-lived neutral particles that in turn decay to bbar b final states, and pp collision data at √s = 7 TeV collected with the ATLAS detector at the LHC during 2011

    Measurement of the production cross section for W-bosons in association with jets in pp collisions at s=7 TeV with the ATLAS detector

    Get PDF
    This Letter reports on a first measurement of the inclusive W + jets cross section in proton-proton collisions at a centre-of-mass energy of 7 TeV at the LHC, with the ATLAS detector. Cross sections, in both the electron and muon decay modes of the W-boson, are presented as a function of jet multiplicity and of the transverse momentum of the leading and next-to-leading jets in the event. Measurements are also presented of the ratio of cross sections sigma (W + >= n)/sigma(W + >= n - 1) for inclusive jet multiplicities n = 1-4. The results, based on an integrated luminosity of 1.3 pb(-1), have been corrected for all known detector effects and are quoted in a limited and well-defined range of jet and lepton kinematics. The measured cross sections are compared to particle-level predictions based on perturbative QCD. Next-to-leading order calculations, studied here for n <= 2, are found in good agreement with the data. Leading-order multiparton event generators, normalized to the NNLO total cross section, describe the data well for all measured jet multiplicitie

    Measurement of the top quark-pair production cross section with ATLAS in pp collisions at \sqrt{s}=7\TeV

    Get PDF
    A measurement of the production cross-section for top quark pairs(\ttbar) in pppp collisions at \sqrt{s}=7 \TeV is presented using data recorded with the ATLAS detector at the Large Hadron Collider. Events are selected in two different topologies: single lepton (electron ee or muon Ό\mu) with large missing transverse energy and at least four jets, and dilepton (eeee, ΌΌ\mu\mu or eΌe\mu) with large missing transverse energy and at least two jets. In a data sample of 2.9 pb-1, 37 candidate events are observed in the single-lepton topology and 9 events in the dilepton topology. The corresponding expected backgrounds from non-\ttbar Standard Model processes are estimated using data-driven methods and determined to be 12.2±3.912.2 \pm 3.9 events and 2.5±0.62.5 \pm 0.6 events, respectively. The kinematic properties of the selected events are consistent with SM \ttbar production. The inclusive top quark pair production cross-section is measured to be \sigmattbar=145 \pm 31 ^{+42}_{-27} pb where the first uncertainty is statistical and the second systematic. The measurement agrees with perturbative QCD calculations.Comment: 30 pages plus author list (50 pages total), 9 figures, 11 tables, CERN-PH number and final journal adde
    • 

    corecore