Preliminary gas hazard evaluation in Greece     

D’Alessandro  Walter  Kyriakopoulos  Konstantinos 《Natural Hazards》2013,69(3):1987-2004

Natural Hazards - Like other geodynamically active areas, Greece is also affected by a large number of geogenic gas manifestations. These occur either in the form of point sources (fumaroles,...  相似文献   

A multisource approach for coastal mapping purposes: Limeni bay,Mani and surrounding area,southern Greece     

Nikolaos Sabatakakis  Konstantinos G. Nikolakopoulos  George Papatheodorou  George Kelasidis 《Earth Science Informatics》2016,9(2):183-196

A multipurpose engineering geological map of a natural heritage site including inland and offshore areas has been compiled to provide information on many aspects for land use optimization, sustainable development and environmental protection. The mapping approach was based on data provided by conventional onland field works, marine remote sensing survey and aerial photo interpretation. These data sources were integrated into a GIS platform allowing reliable mapping solutions. The geological formations encountered were grouped into individual geotechnical units according to uniformity in lithological character, while the seabed sub-bottom structure was also obtained through several seafloor thematic map compilation. Shoreline variability and evolution for a long time period (1945–2008) were also investigated and mapped. The synergistic use of the results deducted from those disciplinary surveys is finally presented in a single engineering geological map covering the onshore and offshore area.  相似文献   

Investigation of flash flood natural causes of Xirolaki Torrent,Northern Greece based on GIS modeling and geomorphological analysis     

Konstantinos Tsanakas  Kalliopi Gaki-Papanastassiou  Kleomenis Kalogeropoulos  Christos Chalkias  Petros Katsafados  Efthimios Karymbalis 《Natural Hazards》2016,80(2):1015-1030

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The geodynamic and limnological evolution of Balkan Lake Ohrid,possibly the oldest extant lake in Europe     

Bernd Wagner  Paul Tauber  Alexander Francke  Niklas Leicher  Steven A. Binnie  Aleksandra Cvetkoska  Elena Jovanovska  Janna Just  Jack H. Lacey  Zlatko Levkov  Katja Lindhorst  Katerina Kouli  Sebastian Krastel  Konstantinos Panagiotopoulos  Arne Ulfers  Dušica Zaova  Timme H. Donders  Andon Grazhdani  Andreas Koutsodendris  Melanie J. Leng  Laura Sadori  Mirko Scheinert  Hendrik Vogel  Thomas Wonik  Giovanni Zanchetta  Thomas Wilke 《Boreas: An International Journal of Quaternary Research》2023,52(1):1-26

Studies of the upper 447 m of the DEEP site sediment succession from central Lake Ohrid, Balkan Peninsula, North Macedonia and Albania provided important insights into the regional climate history and evolutionary dynamics since permanent lacustrine conditions established at 1.36 million years ago (Ma). This paper focuses on the entire 584-m-long DEEP sediment succession and a comparison to a 197-m-long sediment succession from the Pestani site ~5 km to the east in the lake, where drilling ended close to the bedrock, to unravel the earliest history of Lake Ohrid and its basin development. ²⁶Al/¹⁰Be dating of clasts from the base of the DEEP sediment succession implies that the sedimentation in the modern basin started at c. 2 Ma. Geophysical, sedimentological and micropalaeontological data allow for chronological information to be transposed from the DEEP to the Pestani succession. Fluvial conditions, slack water conditions, peat formation and/or complete desiccation prevailed at the DEEP and Pestani sites until 1.36 and 1.21 Ma, respectively, before a larger lake extended over both sites. Activation of karst aquifers to the east probably by tectonic activity and a potential existence of neighbouring Lake Prespa supported filling of Lake Ohrid. The lake deepened gradually, with a relatively constant vertical displacement rate of ~0.2 mm a⁻¹ between the central and the eastern lateral basin and with greater water depth presumably during interglacial periods. Although the dynamic environment characterized by local processes and the fragmentary chronology of the basal sediment successions from both sites hamper palaeoclimatic significance prior to the existence of a larger lake, the new data provide an unprecedented and detailed picture of the geodynamic evolution of the basin and lake that is Europe’s presumed oldest extant freshwater lake.  相似文献   

On the theory of the type III burst exciter     

Robert A. Smith  Melvyn L. Goldstein  Konstantinos Papadopoulos 《Solar physics》1976,46(2):515-527

In situ satellite observations of type III burst exciters at 1 AU show that the beam does not evolve into a plateau in velocity space, contrary to the prediction quasilinear theory. The observations can be explained by a theory that includes mode coupling effects due to excitation of the parametric oscillating two-stream instability and its saturation by anomalous resistivity. The time evolution of the beam velocity distribution is included in the analysis.NAS/NRC Postdoctoral Resident Research Associate.  相似文献   

Size selectivity of diamond and square mesh codends for four commercial Mediterranean fish species   总被引：2，自引：2，他引：2  

Petrakis  George; Stergiou  Konstantinos I. 《ICES Journal of Marine Science》1997,54(1):13-23

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Evaluation of low-rank coals as raw material for Fe and Ca organomineral fertilizer using a new EDXRF method   总被引：2，自引：2，他引：0  

Konstantinos Chassapis  Maria Roulia 《International Journal of Coal Geology》2008,75(3):185-188

A rapid and reliable method for analyzing Fe and Ca in low-rank Greek coals was developed. The presence of Fe and Ca is of importance regarding the potential use of these coals as raw material for organomineral fertilizers. Samples were collected from the main Greek lignite deposits and standards were prepared using Atomic Absorption Spectroscopy (AAS), which were also employed in the Energy Dispersive X-ray Fluorescence (EDXRF) method. The new method offers the advantages of being timesaving, non-destructive and can be easily incorporated in a fertilizer production line. Analysis of low-rank Greek coals demonstrated a significant Fe and Ca content ranging from 0.15 to 1.97 wt.% for Fe and from 0.04 to 2.51 wt.% for Ca. When both EDXRF and AAS techniques were applied, the Fe and Ca concentration values differed less than 5%, demonstrating that both techniques are reliable for low-rank coals in the above concentration range. These EDXRF results may be used as a preliminary test regarding the application of Greek coals in organomineral fertilizer production, given that in these coals iron and calcium are the most abundant metals.  相似文献   

Modeling level selection for seismic analysis of concrete‐filled steel tube/moment‐resisting frames by using fragility curves          下载免费PDF全文

Konstantinos A. Skalomenos  George D. Hatzigeorgiou  Dimitri E. Beskos 《地震工程与结构动力学》2015,44(2):199-220

The seismic behavior of plane moment‐resisting frames (MRFs) consisting of I steel beams and concrete‐filled steel tube (CFT) columns is investigated in this study. More specifically, the effect of modeling details of each individual component of CFT‐MRFs, such as the composite CFT columns, the beam‐column connections, the panel zones, and the steel I beams on their seismic behavior, is studied through comparisons against available experimental results. Then, fragility curves are constructed for three typical CFT‐MRFs, designed according to European codes, for various levels of modeling sophistication through nonlinear time‐history analyses. On the basis of these fragility curves, one can select the appropriate modeling level of sophistication that can lead to the desired seismic behavior for a given seismic intensity. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

Analysing the topology of seismicity in the Hellenic arc using complex networks     

Eleni Daskalaki  Gerassimos A. Papadopoulos  Konstantinos Spiliotis  Constantinos Siettos 《Journal of Seismology》2014,18(1):37-46

Based on the theory of complex networks, we quantify for the first time correlations between seismic events occurring in the Hellenic arc and Trench system, which is the most seismogenic structure in the European–Mediterranean region. We examine how relatively strong events with their aftershock sequences trigger phase transitions of the underlying network topology of seismic activity from random to scale-free structures. In particular, we show that the network is characterized by a highly clustered spatial structure giving rise to heterogeneous networks exhibiting enhanced small-world attributes.  相似文献   

Seismic response analysis of adjacent liquid‐storage tanks          下载免费PDF全文

Konstantinos Mykoniou  Christoph Butenweg  Britta Holtschoppen  Sven Klinkel 《地震工程与结构动力学》2016,45(11):1779-1796

A refined substructure technique in the frequency domain is developed, which permits consideration of the interaction effects among adjacent containers through the supporting deformable soil medium. The tank‐liquid systems are represented by means of mechanical models, whereas discrete springs and dashpots stand for the soil beneath the foundations. The proposed model is employed to assess the responses of adjacent circular, cylindrical tanks for harmonic and seismic excitations over wide range of tank proportions and soil conditions. The influence of the number, spatial arrangement of the containers and their distance on the overall system's behavior is addressed. The results indicate that the cross‐interaction effects can substantially alter the impulsive components of response of each individual element in a tank farm. The degree of this impact is primarily controlled by the tank proportions and the proximity of the predominant natural frequencies of the shell‐liquid‐soil systems and the input seismic motion. The group effects should be not a priori disregarded, unless the tanks are founded on shallow soil deposit overlying very stiff material or bedrock. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献