101 research outputs found
A Provenance Data Model for Astronomy
No full texthttp://www.aspbooks.org/publications/521/450.pdfInternational audienceIn Astronomy as well as in other sciences it is of crucial importance to have information about the origin and history of data, i.e. its provenance information. The IVOA Provenance Data Model shall record this information in a consistent and interoperable way for astronomical data. This will enable scientists to use common tools for discovering data based on their provenance and help them to gain a better understanding of the data, its processing and to judge the data's quality and reliability
A Provenance Data Model for Astronomy
No full texthttp://www.aspbooks.org/publications/521/450.pdfInternational audienceIn Astronomy as well as in other sciences it is of crucial importance to have information about the origin and history of data, i.e. its provenance information. The IVOA Provenance Data Model shall record this information in a consistent and interoperable way for astronomical data. This will enable scientists to use common tools for discovering data based on their provenance and help them to gain a better understanding of the data, its processing and to judge the data's quality and reliability
Increased expression of 5-HT1B receptors by Herpes simplex virus gene transfer in septal neurons: New in vitro and in vivo models to study 5-HT1B receptor function
No full textMaturation and maintenance of cholinergic medial septum neurons require glucocorticoid receptor signaling.
No full textMaturation and maintenance of cholinergic medial septum neurons require glucocorticoid receptor signaling
No full textThe use of non-radioactive iodine as a label in immunoassays
No full textThe research described in this thesis has centered on the development of a nonradioactive iodine label for use in immunoassays. A protein can be iodinated with nonradioactive iodine, used in an immunoassay, and the iodine label detected by a chemical method.
A microassay was developed to measure iodine by means of its catalytic effect on the
oxidation of antimony(III) by cerium(IV). The reaction was monitored both spectrophotometrically, by measuring the absorbance of cerium(IV), and fluorimetrically, by measuring the fluorescence of cerium(III) or by measuring the fluorescence produced by the oxidation of 8-hydroxyquinoline-5-sulphonic acid with cerium(IV). The detection of potassium iodide, iodine-containing organic compounds and iodinated proteins was possible using the microassay. Iodinated Bolton-Hunter reagent, an iodine-containing hapten which is used to iodinate proteins, could also be detected using the microassay. The catalytic activity of iodide is greater than that of iodine in iodocompounds, therefore, it was not possible to achieve the same sensitivity using IBHR as with potassium iodide.
A two-site immunoassay for the measurement of human IgG was set up and the effectiveness of non-radioactive iodine as a label in the immunoassay was illustrated using several assay formats. Initially, IBHR-labelled antibodies were used and directly compared to enzyme-labelled antibodies. The cerium (IV) - antimony(III) reaction was successfully used to detect the iodine label. The results obtained were comparable to those obtained using an enzyme label, with respect to accuracy and precision of the standards and with respect to the results obtained for serum samples. However, the use of enzyme-labelled antibodies enabled measurement of lower concentrations of human IgG.
In order to improve the detection limit when using the iodine label, the use of the avidin-biotin system and of bispecific F(ab’)2 antibodies was investigated. IBHRlabelled avidin and IBHR-labelled biotin were prepared, and used in a labelled avidinbiotin (LAB) immunoassay and bridged avidin-biotin (BRAB) immunoassay, respectively. Bispecific F(ab’)2 antibodies were prepared by a chemical method, and were used in an immunoassay as bridging agents between human IgG and iodinated BSA. An improvement in the detection limit was achieved using IBHR-labelled avidin in the LAB immunoassay.
An immunoassay for the measurement of thyroxine, which eliminates the necessity to prepare labelled derivatives of antigen or antibody, was developed. In this assay format, anti-thyroxine antibodies were used to capture thyroxine. Thyroxine contains four iodine atoms which served as the label, and these were monitored using the cerium (IV) - antimony (HI) reaction
Investigation on low-speed pre-ignition from the quantification and identification of engine oil droplets release under ambient pressure conditions
No full text[EN] One source of low-speed pre-ignition in turbocharged gasoline direct injection engines is the presence of oil droplets in the combustion chamber. In this study, oil droplets released due to the piston reciprocating motion, have been quantified as function of oil viscosity and engine speed, by means of a motored test rig under ambient pressure conditions. Oil droplets were collected using a sandwich-like support and absorbing paper. An image processing methodology was developed to identify critical regions of the piston prone to the appearance of oil. Results show that oil is scrapped by the piston rings and released to the combustion chamber in zones transverse to the piston pin, at speeds as low as 500 rpm. Oil viscosity does not have a determining effect on the oil amount reaching the combustion chamber, while engine speed greatly increases this phenomenon, with a critical point at 2500 rpm and oil temperature of 80 degrees C.Author Sophia Bastidas would like to thank the support of the program Ayudas de Investigacion y Desarrollo (PAID-01-17) of the Universitat Politecnica de Valencia.Tormos, B.; García-Oliver, JM.; Bastidas-Moncayo, KS.; Domínguez, B.; Oliva, F.; Cárdenas, D. (2020). Investigation on low-speed pre-ignition from the quantification and identification of engine oil droplets release under ambient pressure conditions. Measurement. 163:1-10. https://doi.org/10.1016/j.measurement.2020.107961S110163Jatana, G. S., Splitter, D. A., Kaul, B., & Szybist, J. P. (2018). Fuel property effects on low-speed pre-ignition. Fuel, 230, 474-482. doi:10.1016/j.fuel.2018.05.060A. Zahdeh, P. Rothenberger, W. Nguyen, M. Anbarasu, S. Schmuck-Soldan, J. Schaefer, at al, Fundamental approach to investigate pre-ignition in boosted SI engines, in: SAE 2011 World Congress and Exhibition, SAE International, 2011. doi:10.4271/2011-01-0340.E.J. Passow, P. Sethi, M. Maschewske, J. Bieneman, K. Karrip, P. Truckel, An introduction to how low speed pre ignition affects engine components, in: WCX 17: SAE World Congress Experience, SAE International, 2017. doi:10.4271/2017-01-1042.A. Isenstadt, J. German, M. Dorobantu, D. Boggs, T. Watson, Downsized, boosted gasoline engines, Tech. rep., The International Council on Clean Transportation (2016). URL .Hu, B., Akehurst, S., & Brace, C. (2015). Novel approaches to improve the gas exchange process of downsized turbocharged spark-ignition engines: A review. International Journal of Engine Research, 17(6), 595-618. doi:10.1177/1468087415599866Zaccardi, J.-M., & Escudié, D. (2014). Overview of the main mechanisms triggering low-speed pre-ignition in spark-ignition engines. International Journal of Engine Research, 16(2), 152-165. doi:10.1177/1468087414530965M. Amann, T. Alger, B. Westmoreland, A. Rothmaier, The effects of piston crevices and injection strategy on low-speed pre-ignition in boosted SI engines, in: SAE 2012 World Congress and Exhibition, SAE International, 2012. doi:10.4271/2012-01-1148.T. Kuboyama, Y. Moriyoshi, K. Morikawa, Visualization and analysis of LSPI mechanism caused by oil droplet, particle and deposit in highly boosted SI combustion in low speed range, in: SAE 2015 World Congress and Exhibition, SAE International, 2015. doi:10.4271/2015-01-0761.Spicher, U., Gohl, M., Magar, M., & Hadler, J. (2015). The Role of Engine Oil in Low-speed Pre-ignition. MTZ worldwide, 77(1), 60-63. doi:10.1007/s38313-015-0079-6V.B. Kalaskar, A. Swarts, T. Alger, Impact of engine age and engine hardware on low-speed pre-ignition, in: International Powertrains, Fuels and Lubricants Meeting, SAE International, 2018. doi:10.4271/2018-01-1663.O. Welling, N. Collings, J. Williams, J. Moss, Impact of lubricant composition on Low-speed Pre-Ignition, in: SAE 2014 World Congress and Exhibition, SAE International, 2014. doi:10.4271/2014-01-1213.Huang, Y., Li, Y., Zhang, W., Meng, F., & Guo, Z. (2017). 3D simulation study on the influence of lubricant oil droplets on pre-ignition in turbocharged DISI engines. Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, 232(12), 1677-1693. doi:10.1177/0954407017734695T. Ito, Y. Abe, J. Tanaka, Lubricating oil droplets in cylinder on abnormal combustion in supercharged SI engine, in: SAE/JSAE Small Engine Technology Conference, SAE International, 2018. doi:10.4271/2018-32-0008.T. Miyasaka, K. Miura, N. Hayakawa, T. Ishino, A. Iijima, H. Shoji, K. Tamura, T. Utaka, H. Kamano, A study on the effect of a calcium-based engine oil additive on abnormal SI engine combustion, in: SAE/JSAE 2014 Small Engine Technology Conference and Exhibition, SAE International, 2014. doi:10.4271/2014-32-0092.M.C. Kocsis, T. Briggs, G. Anderson, The impact of lubricant volatility, viscosity and detergent chemistry on low speed pre-ignition behavior, in: WCX 17: SAE World Congress Experience, SAE International, 2017. doi:10.4271/2017-01-0685.API, Latest oil classifications, [Accessed: 17/10/2019]. https://www.api.org/products-and-services/engine-oil/eolcs-categories-and-classifications/latest-oil-classifications.Insight, Why ILSAC GF-6?, [Accessed: 25/10/2019]. .SAE International, SAE J300 Engine Oil Viscosity Classification, United States, 2015.Kalghatgi, G. T., & Bradley, D. (2012). Pre-ignition and ‘super-knock’ in turbo-charged spark-ignition engines. International Journal of Engine Research, 13(4), 399-414. doi:10.1177/1468087411431890O. Welling, J. Moss, J. Williams, N. Collings, Measuring the impact of engine oils and fuels on low-speed pre-ignition in downsized engines, in: SAE 2014 World Congress and Exhibition, SAE International, 2014. doi:10.4271/2014-01-1219
CUBES phase a design overview: the Cassegrain U-Band efficient spectrograph for the very large telescope
No full textWe present the baseline conceptual design of the Cassegrain U-Band Efficient Spectrograph (CUBES) for the Very Large Telescope. CUBES will provide unprecedented sensitivity for spectroscopy on a 8 – 10 m class telescope in the ground ultraviolet (UV), spanning a bandwidth of ≥ 100 nm that starts at 300 nm, the shortest wavelength accessible from the ground. The design has been optimized for end-to-end efficiency and provides a spectral resolving power of R≥ 20000, that will unlock a broad range of new topics across solar system, Galactic and extraglactic astronomy. The design also features a second, lower-resolution (R∼ 7000) mode and has the option of a fiberlink to the UVES instrument for simultaneous observations at longer wavelengths. Here we present the optical, mechanical and software design of the various subsystems of the instrument after the Phase A study of the project. We discuss the expected performances for the layout choices and highlight some of the performance trade-offs considered to best meet the instrument top-level requirements. We also introduce the model-based system engineering approach used to organize and manage the project activities and interfaces, in the context that it is increasingly necessary to integrate such tools in the development of complex astronomical projects
IceTop: The surface component of IceCube
No full textIceTop, the surface component of the IceCube Neutrino Observatory at the South Pole, is an air shower array with an area of 1 km2. The detector allows a detailed exploration of the mass composition of primary cosmic rays in the energy range from about 100 TeV to 1 EeV by exploiting the correlation between the shower energy measured in IceTop and the energy deposited by muons in the deep ice. In this paper we report on the technical design, construction and installation, the trigger and data acquisition systems as well as the software framework for calibration, reconstruction and simulation. Finally the first experience from commissioning and operating the detector and the performance as an air shower detector will be discussed.The IceCube Collaboration ... G.C. Hill ... et al
Search for Galactic PeV Gamma Rays with the IceCube Neutrino Observatory
No full textGamma-ray induced air showers are notable for their lack of muons, compared to hadronic showers. Hence, air shower arrays with large underground muon detectors can select a sample greatly enriched in photon showers by rejecting showers containing muons. IceCube is sensitive to muons with energies above ∼500 GeV at the surface, which provides an efficient veto system for hadronic air showers with energies above 1 PeV. One year of data from the 40-string IceCube configuration was used to perform a search for point sources and a Galactic diffuse signal. No sources were found, resulting in a 90% C.L. upper limit on the ratio of gamma rays to cosmic rays of 1.2×10 -3 for the flux coming from the Galactic plane region (-80 â‰2lâ‰2-30; -10 â‰2bâ‰25) in the energy range 1.2-6.0 PeV. In the same energy range, point source fluxes with E-2 spectra have been excluded at a level of (E/TeV)2dΦ/ dE∼10-12-10-11 cm-1 s-1 TeV -1 depending on source declination. The complete IceCube detector will have a better sensitivity (due to the larger detector size), improved reconstruction, and vetoing techniques. Preliminary data from the nearly final IceCube detector configuration have been used to estimate the 5-yr sensitivity of the full detector. It is found to be more than an order of magnitude better, allowing the search for PeV extensions of known TeV gamma-ray emitters. © 2013 American Physical Society.0IceCube CollaborationSCOPUS: ar.jinfo:eu-repo/semantics/publishe
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