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Yiannis Liritzis 《Earth, Moon, and Planets》1988,42(2):151-162
Geomagnetic virtual pole positions (VGP's) calculated from archaeomagnetic directional data are compared with three ancient accounts of low latitude observations of the Aurorae boreales, viz. by Aristotle (384–322 BC), Seneca (55 BC-40 AD) and simultaneously by Chinese astronomers in Hangzhou, China and by European observers in Prague in 1138 AD, October 13th.The geomagnetic latitudes of these VGP's ranged from 65 to 70 . Inclination and declination values have also been calculated for the regions of interest, assuming dipole field symmetry. 相似文献
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Katsirakis Manolis Tsompanakis Yiannis Psarropoulos Prodromos N. 《Geotechnical and Geological Engineering》2022,40(6):3325-3341
Geotechnical and Geological Engineering - The seismic design of new retaining structures is usually performed following modern seismic norms. Nonetheless, there are various monumental retaining... 相似文献
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Stephen R. Kane T. A. Lister rew Collier Cameron Keith Horne David James Don L. Pollacco Rachel A. Street Yiannis Tsapras 《Monthly notices of the Royal Astronomical Society》2005,362(1):117-126
Recent wide field photometric surveys, which target a specific field for long durations, are ideal for studying both long- and short-period stellar variability. Here, we report on 75 variable stars detected during the observations of a field in Pegasus using the Wide Angle Search for Planets Prototype (WASP0) instrument, 73 of which are new discoveries. The variables detected include 16 δ Scuti stars, 34 eclipsing binaries, 3 BY Draconis stars and 4 RR Lyraes. We estimate that the fraction of stars in the field brighter than V ∼ 13.5 exhibiting variable behaviour with an amplitude greater than 0.6 per cent rms is ∼0.4 per cent. These results are compared with other wide field stellar variability surveys, and implications for detecting transits due to extra-solar planets are discussed. 相似文献
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Yiannis Tsapras Rachel A. Street Keith Horne Alan Penny Fraser Clarke Hans Deeg Francisco Garzon Simon Kemp Maria Rosa Zapatero Osorio Alejandro Oscoz Abad Santiago Madruga Sanchez Carlos Eiroa Alcione Mora Antxon Alberdi rew Cameron John K. Davies Roger Ferlet Carol Grady Allan W. Harris Javier Palacios reas Quirrenbach Heike Rauer Jean Schneider Dolf de Winter Bruno Merin Enrique Solano 《Monthly notices of the Royal Astronomical Society》2001,325(3):1205-1212
In 1998 the EXPORT team monitored microlensing event light curves using a charge-coupled device (CCD) camera on the IAC 0.8-m telescope on Tenerife to evaluate the prospect of using northern telescopes to find microlens anomalies that reveal planets orbiting the lens stars. The high airmass and more limited time available for observations of Galactic bulge sources make a northern site less favourable for microlensing planet searches. However, there are potentially a large number of northern 1-m class telescopes that could devote a few hours per night to monitor ongoing microlensing events. Our IAC observations indicate that accuracies sufficient to detect planets can be achieved despite the higher airmass. 相似文献
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Areti Gianni Miltiadis Zamparas Ioannis T. Papadas George Kehayias Yiannis Deligiannakis Ierotheos Zacharias 《Aquatic Geochemistry》2013,19(1):77-95
The balance between physicochemical processes, influencing vertical and temporal distributions of metal compounds in one relatively isolated anoxic environment, constitutes the objective of the present work. Ion activity product (IAP) was calculated for manganese and iron sulfides, in order to define the metal sulfide forms that control Fe and Mn solubility in the bottom waters of anoxic lagoons. Iron solubility depended on amorphous FeS formation, while manganese sulfides were a minor component in a solid solution lowering its solid-phase activity. A theoretical physicochemical model was developed for the iron speciation, based on experimental pH and redox potential data. A very good match was achieved for the measured and the theoretical total dissolved iron, at all depths. The dominance of oxidant iron species Fe(OH) 3 ? in the surface waters and their sequence by FeSH+ and FeSaq in the deeper layers brings out the influence of physicochemical parameters (dissolved oxygen, sulfide, pH and Eh) in vertical distribution of dissolved metal species, in anoxic/hypoxic basins. Based on these findings, we can conclude that the distribution of manganese and iron is of special interest, not only because these are the indicators of redox conditions but also for the role of their oxidized/reduced forms in the formation of the biogeochemical structure of redox zone. 相似文献
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Savvidis Yiannis Antoniou Alexander Moriki Amalia Stoilas Vasilis-Orestis 《Ocean Science Journal》2019,54(4):543-558
Ocean Science Journal - The coastal area of Chalastra (NW Thessaloniki’s Gulf, Northern Greece) features prominent mussel farming activity as well as fishing activity. These activities are... 相似文献