| 1. |
- Schael, S, et al.
(author)
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Precision electroweak measurements on the Z resonance
- 2006
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In: Physics Reports. - : Elsevier BV. - 0370-1573 .- 1873-6270. ; 427:5-6, s. 257-454
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Research review (peer-reviewed)abstract
- We report on the final electroweak measurements performed with data taken at the Z resonance by the experiments operating at the electron-positron colliders SLC and LEP. The data consist of 17 million Z decays accumulated by the ALEPH, DELPHI, L3 and OPAL experiments at LEP, and 600 thousand Z decays by the SLID experiment using a polarised beam at SLC. The measurements include cross-sections, forward-backward asymmetries and polarised asymmetries. The mass and width of the Z boson, m(Z) and Gamma(Z), and its couplings to fermions, for example the p parameter and the effective electroweak mixing angle for leptons, are precisely measured: m(Z) = 91.1875 +/- 0.0021 GeV, Gamma(Z) = 2.4952 +/- 0.0023 GeV, rho(l) = 1.0050 +/- 0.0010, sin(2)theta(eff)(lept) = 0.23153 +/- 0.00016. The number of light neutrino species is determined to be 2.9840 +/- 0.0082, in agreement with the three observed generations of fundamental fermions. The results are compared to the predictions of the Standard Model (SM). At the Z-pole, electroweak radiative corrections beyond the running of the QED and QCD coupling constants are observed with a significance of five standard deviations, and in agreement with the Standard Model. Of the many Z-pole measurements, the forward-backward asymmetry in b-quark production shows the largest difference with respect to its SM expectation, at the level of 2.8 standard deviations. Through radiative corrections evaluated in the framework of the Standard Model, the Z-pole data are also used to predict the mass of the top quark, m(t) = 173(+10)(+13) GeV, and the mass of the W boson, m(W) = 80.363 +/- 0.032 GeV. These indirect constraints are compared to the direct measurements, providing a stringent test of the SM. Using in addition the direct measurements of m(t) and m(W), the mass of the as yet unobserved SM Higgs boson is predicted with a relative uncertainty of about 50% and found to be less than 285 GeV at 95% confidence level. (c) 2006 Elsevier B.V. All rights reserved.
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| 2. |
- Laj, P., et al.
(author)
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Measuring Atmospheric Composition Change
- 2009
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In: Atmospheric Environment. - : Elsevier BV. - 1873-2844 .- 1352-2310. ; 43:33, s. 5351-5414
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Journal article (peer-reviewed)abstract
- Scientific findings from the last decades have clearly highlighted the need for a more comprehensive approach to atmospheric change processes. In fact, observation of atmospheric composition variables has been an important activity of atmospheric research that has developed instrumental tools (advanced analytical techniques) and platforms (instrumented passenger aircrafts, ground-based in-situ and remote sensing stations, earth observation satellite instruments) providing essential information on the composition of the atmosphere. The variability of the atmospheric system and the extreme complexity of the atmospheric cycles for short-lived gaseous and aerosol species have led to the development of complex models to interpret observations, test our theoretical understanding of atmospheric chemistry and predict future atmospheric composition. The validation of numerical models requires accurate information concerning the variability of atmospheric composition for targeted species via comparison with observations and measurements. In this paper, we provide an overview of recent advances in instrumentation and methodologies for measuring atmospheric composition changes from space, aircraft and the surface as well as recent improvements in laboratory techniques that permitted scientific advance in the field of atmospheric chemistry. Emphasis is given to the most promising and innovative technologies that will become operational in the near future to improve knowledge of atmospheric composition. Our current observation capacity, however, is not satisfactory to understand and predict future atmospheric composition changes, in relation to predicted climate warming. Based on the limitation of the current European observing system, we address the major gaps in a second part of the paper to explain why further developments in current observation strategies are still needed to strengthen and optimise an observing system not only capable of responding to the requirements of atmospheric services but also to newly open scientific questions.
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| 3. |
- Vigolo, Birgitte, et al.
(author)
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Multiscale characterization of single-walled carbon nanotube/polymer composites by coupling Raman and Brillouin spectroscopy
- 2009
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In: The Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 113:41, s. 17648-17654
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Journal article (peer-reviewed)abstract
- The present paper reports on an original experimental approach to the characterization of SWNT/polymer composites. This work deals with the multiscale characterization of nanocomposites. Covalently functionalized SWNTs were incorporated in a PMMA matrix using an in situ polymerization procedure. We show that their presence does not affect the radical polymerization process. Combining Brillouin and Raman spectroscopy, we were able to associate the obtained mechanical properties of the material at the macroscopic scale to the state of functionalization of the SWNTs within the polymer matrix.
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| 4. |
- Vogt, Carmen M., et al.
(author)
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Optimised Synthetic Route for Tuneable Shell SiO2@Fe3O4 Core-Shell Nanoparticles
- 2009
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In: Materials Research Society Symposium Proceedings. ; , s. 209-214
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Conference paper (other academic/artistic)abstract
- Multifunctional nanoparticles (that have in their structure different components that can perform various functions) are subject of intensive research activities as they find a large variety of applications in numerous biomedical fields from enhancement of image contrast in MRI to different magnetically controllable drug delivery systems. In this study we report on the synthesis of well-separated, monodisperse single coreshell SiO2@Fe3O4 nanoparticles with an overall diameter of ~30 nm. The influence of stirring rate and reaction time on synthesis of tuneable shell thickness core-shell nanoparticles is reported. Particles’ cell toxicity and performance as MRI contrast agents were also studied due to their promising biological applications (as contrast agents, cell labelling and separation, drug delivery systems, etc.) and results are promising in terms of MRI performance as well as having no significant cytotoxicity.
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