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Roberto Viotti Cesare D. La Padula Domenico Nanni Agostino Vignato 《Astrophysics and Space Science》2001,276(1):81-88
We present the basic concepts of the two-mirror, three-reflection optical system (2MTRT), and discuss the important benefits of such a system for space projects: wide ( 2°) correctedand unvignetted FOV, without the use of refractive optics for thefield correction, planarity of the focal surface for an optimizedinstallation of wide area detectors, easy telescope adjustement, small volume and little mass.We also report the results of optical tests made with a 30 cm prototype,equipped with a 2k × 2k CCD camera, and give examples of scientific programmes which can be performed from space and in hostile terrestrial sites such as the Antarctic Plateau. 相似文献
123.
G. Ferrara M. Preite-Martinez H. P. Taylor Jr. S. Tonarini B. Turi 《Contributions to Mineralogy and Petrology》1986,92(3):269-280
18O/16O,87Sr/86Sr and chemical analyses were made on 39 lavas and ignimbrites from M. Vulsini, the most northerly district of the K-rich Quaternary Roman Province of Italy. These rocks belong mainly to the undersaturated, leucite-bearing (High-K) series, but also included are samples from the less abundant, SiO2-saturated, hypersthene-(quartz)-normative (Low-K) series. The effects of post-eruption alteration on the
18O of these lavas were taken into account by analyzing phenocrysts or by using the extrapolation procedure developed for the nearby Alban Hills center. Because of the high Sr contents (500–2400 ppm), the87Sr/86Sr ratios of these rocks were little affected by such alteration processes. The M. Vulsini volcanics have Sr- and O-isotopic ratios much less uniform, and on the average much higher, than at any of the other volcanic centers of the province:87Sr/86Sr=0.7097 to 0.7168;
18O=6.5 to 13.8. This is attributable to the fact that M. Vulsini is one of the sites of greatest crustal assimilation and hybridism between K-rich Roman magmas and SiO2-rich Tuscan anatectic magmas. The High-K series parent magmas at M. Vulsini had a very high and uniform87Sr/86Sr=0.7102 to 0.7104, and a somewhat more variable
18O=+5.5 to +7.5; they must have come from an upper mantle source region previously metasomatically enriched in87Sr and LIL elements. These18O/16O and87Sr/86Sr ratios are identical to the parent magma at the Alban Hills, 120 km to the south, where Low-K lavas are absent. Low-K series magmas at M. Vulsini originated from a lower-87Sr source region than the High-K series (<0.7097); a similar relationship is observed in all of the other localities in Italy where the two magma series coexist.Contribution No. 4167, Division of Geological and Planetary Sciences, California Institute of Technology 相似文献
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A new monitoring station for debris flows in the European Alps: first observations in the Gadria basin 总被引:1,自引:0,他引:1
F. Comiti L. Marchi P. Macconi M. Arattano G. Bertoldi M. Borga F. Brardinoni M. Cavalli V. D’Agostino D. Penna J. Theule 《Natural Hazards》2014,73(3):1175-1198
Debris-flow monitoring in instrumented areas is an invaluable way to gather field data that may improve the understanding of these hazardous phenomena. A new experimental site has been equipped in the Autonomous Province of Bozen-Bolzano (Eastern Alps, Italy) for both monitoring purposes and testing early warning systems. The study site (Gadria basin) is a 6.3 km2 catchment subjected to frequent debris flows. The monitoring system in the Gadria basin consists of rain gauges, radar sensors, geophones, video cameras, piezometers and soil moisture probes. Transmission of data and alerts from the instruments exploits in part radio technology. The paper presents the data gathered during the first three years of activity, with two debris-flow events recorded at the station varying in magnitude and characteristics, and discusses the perspectives of debris-flow monitoring and related research. 相似文献
126.
Domenico Gallipoli Agostino Walter Bruno Céline Perlot Joao Mendes 《Acta Geotechnica》2017,12(3):463-478
Much research has been devoted over the past 30 years to the development of construction materials that can lower the environmental and economic costs of buildings over their entire life by reducing embodied energy, minimizing air conditioning needs and cutting down demolition waste. In this respect, raw earth is an attractive material because it is natural and largely available. In its simplest form, this material consists of a compacted mixture of soil and water which is put in place with the least possible transformation. Raw earth construction has been practised in ancient times but has only recently been rediscovered thanks to modern technology, which has improved fabrication efficiency. If properly manufactured, raw earth exhibits comparable mechanical characteristics and better hygro-thermal properties than concrete or fired bricks. After a brief historical overview, we discuss the advantages of raw earth construction in terms of environmental impact, energy consumption and indoor air quality together with the main obstacles to its wider dissemination. We also review the hydro-thermo-mechanical behaviour of raw earth in the context of the recent geotechnical literature, by examining the dependency of key parameters such as strength, stiffness and moisture retention on: (a) material variables (e.g. particle size and mineralogy), (b) manufacturing variables (e.g. density and stabilization) and (c) environmental variables (e.g. pore suction, ambient humidity and temperature). 相似文献
127.
Quillon Harpham Olalla Gimeno Antonio Parodi Daniele D’Agostino 《Earth Science Informatics》2017,10(2):219-234
The purpose of this paper is to report on and analyse an international consultation into hydro-meteorological e-Science environments with the objective of identifying key functions and features together with exploring show-stopping issues and organisational structure. Transatlantic experiences were compared and contrasted. Including strong participation from both Europe and the USA with high quality responses from experienced practitioners, the consultation was undertaken as part of a joint initiative and took the form of an online questionnaire supported by a set of stakeholder interviews and other discussions. Topics included were functions and features such as provision of numerical models and data, usability, and ease of access; show-stopping issues such as flexibility, reliability and longevity; centralised and distributed structures, and funding models. The results demonstrated a broadly similar set of experiences and implied a future as an evolution of that which exists today. The consultation exercise ran alongside the development of the DRIHM e-Infrastructure which had, in itself, already benefitted from the prior DRIHMS consultation. Results were fed in to the development process at appropriate intervals allowing the consultation to shape the resultant services. 相似文献
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