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- Schael, S, et al.
(författare)
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Precision electroweak measurements on the Z resonance
- 2006
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Ingår i: Physics Reports. - : Elsevier BV. - 0370-1573 .- 1873-6270. ; 427:5-6, s. 257-454
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Forskningsöversikt (refereegranskat)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. |
- Benetti, M., et al.
(författare)
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POLYSILICON MESOSCOPIC WIRES COATED BY Pd AS H(2) SENSORS
- 2009
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Ingår i: PROCEEDINGS OF THE 13TH ITALIAN CONFERENCE ON SENSORS AND MICROSYSTEMS. - SINGAPORE : WORLD SCIENTIFIC PUBL CO PTE LTD. ; , s. 161-165
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Konferensbidrag (refereegranskat)abstract
- In this work a novel monocrystalline silicon nanowires array has been investigated and presented as hydrogen sensor, designed and fabricated by employing high resolution microfabrication techniques and featuring a high surface/volume ratio. The nanowires arrays makes up the channel of a MOS system, palladium-silicon dioxide-silicon. Several devices have been fabricated by using a SOI (Silicon On Insulator) substrate, Source and Drain have been geometrically patterned by optical lithography and Boron p-doped. Electron Beam Litography (EBL) defined the MOS channel made up of a nanowires array of different length and width in different transistors. The pads of Source and Drain have been manufactured with an aluminium film deposition. The Gate has been fabricated with a grown silicon oxide layer (17.4 nm) and Palladium has been used as gate contact. Polarizing and exposing the device to H(2)/N(2) cycles at different concentrations some preliminary measurements have been successfully conducted.
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| 7. |
- Paolesse, R., et al.
(författare)
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Insights on the chemistry of a,c-biladienes from a CSPT investigation
- 2008
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Ingår i: New Journal of Chemistry. - : Royal Society of Chemistry (RSC). - 1144-0546 .- 1369-9261. ; 32:7, s. 1162-1166
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Tidskriftsartikel (refereegranskat)abstract
- Computer Screen Photoassisted Technique (CSPT) is a recent interesting approach for the development of optical sensor platforms using ubiquitous devices. We demonstrate here that the information obtained by CSPT measurements can be useful for other than sensing purposes and a computer set and a web camera can also be exploited as spectroscopic technique for the characterization of the compounds used as indicators. CSPT measurement data have been used to characterize novel features of the a,c-biladiene chemistry, which have been later confirmed by photophysical characterization carried out using classical instrumentation. The demonstrated analytical capabilities of a regular computer-web camera set reach a degree of complexity approaching that of fluorescence excitation-emission spectroscopy, something remarkable considering the exploitation of familiar and already well distributed devices. © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.
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| 8. |
- Di, Natale C., et al.
(författare)
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An experimental biomimetic platform for artificial olfaction
- 2008
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 3:9
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Tidskriftsartikel (refereegranskat)abstract
- Artificial olfactory systems have been studied for the last two decades mainly from the point of view of the features of olfactory neuron receptor fields. Other fundamental olfaction properties have only been episodically considered in artificial systems. As a result, current artificial olfactory systems are mostly intended as instruments and are of poor benefit for biologists who may need tools to model and test olfactory models. Herewith, we show how a simple experimental approach can be used to account for several phenomena observed in olfaction. An artificial epithelium is formed as a disordered distributed layer of broadly selective color indicators dispersed in a transparent polymer layer. The whole epithelium is probed with colored light, imaged with a digital camera and the olfactory response upon exposure to an odor is the change of the multispectral image. The pixels are treated as olfactory receptor neurons, whose optical properties are used to build a convergence classifier into a number of mathematically defined artificial glomeruli. A non-homogenous exposure of the test structure to the odours gives rise to a time and spatial dependence of the response of the different glomeruli strikingly similar to patterns observed in the olfactory bulb. The model seems to mimick both the formation of glomeruli, the zonal nature of olfactory epithelium, and the spatio-temporal signal patterns at the glomeruli level. This platform is able to provide a readily available test vehicle for chemists developing optical indicators for chemical sensing purposes and for biologists to test models of olfactory system organization. © 2008 Di Natale et al.
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| 9. |
- Di Natale, C, et al.
(författare)
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An artificial olfaction system based on the optical imaging of a large array of chemical reporters
- 2009
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Ingår i: SENSORS AND ACTUATORS B-CHEMICAL. - : Elsevier BV. - 0925-4005. ; 142:2, s. 412-417
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Tidskriftsartikel (refereegranskat)abstract
- Electronic noses are object of research since more than two decades; nonetheless. the analogies between natural and olfaction systems are still limited to the selectivity properties of the receptors. The implementation of more sophisticated features such as the large number of receptors and the glomeruli layer have been hampered by technical difficulties related to the management of a large number of contemporaneous signals. As demonstrated in the past, optical imaging is a read-out technique for sensors development that can provide large sensor arrays. In this paper an artificial olfaction system based on the imaging of a continuous layer of chemical indicators is illustrated. The system incorporates an array of thousands of sensors, corresponding to the pixels of the image. The choice of Computer Screen Photoassisted Technology as a platform for optical interrogation of the sensing layer allows for the definition of a strategy for an automatic definition of a glomeruli layer based on the classification of the optical fingerprints of the image pixels. Chemical indicators were dissolved into a polymeric matrix providing the further property of odor diffusion mimicking the functions of the olfactory mucosa. The system has been tested in a simple experiment and data have been treated applying a lateral inhibition to the glomeruli layer resulting in a dynamic pattern resembling that observed in natural olfaction.
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| 10. |
- Filippini, Daniel, 1968-, et al.
(författare)
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Computer screen photo-assisted techniques for global monitoring of environmental and sanitary parameters
- 2007
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Ingår i: Sensors and actuators. B, Chemical. - : Elsevier BV. - 0925-4005 .- 1873-3077. ; 121:1, s. 93-102
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Tidskriftsartikel (refereegranskat)abstract
- The computer screen photo-assisted technique (CSPT) is a measuring method that uses regular computer screens as controlled light sources and web cameras as imaging detectors for optical evaluations of sensing substances, which optical properties respond to target analytes. The fact, that CSPT uses a globally distributed and familiar infrastructure as instrumentation and that is able to serve multiple targets with the same setup, makes it an attractive candidate for home testing. This article reviews the CSPT concept and focuses in two recent studies that demonstrate thorough CSPT determinations using a handy and eventually disposable assay format, with the potential to be as ubiquitous as the CSPT platforms themselves. The implications of such combination of technologies is discussed, and its potential to support the global monitoring of environmental and sanitary parameters, using Internet geography browsers, is analyzed. © 2006 Elsevier B.V. All rights reserved.
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