Erratum to: A cervelleite-like mineral and other Ag-Cu-Te-S minerals [Ag2CuTeS and (Ag,Cu)2TeS] in gold-bearing veins in metamorphic rocks of the Cycladic Blueschist Unit, Kallianou, Evia Island, Greece     

Panagiotis Christos Voudouris  Paul G. Spry  Gregory Aarne Sakellaris  Constantinos Mavrogonatos 《Mineralogy and Petrology》2011,103(1-4):179-179

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Porting of a wildfire risk and fire spread application into a cloud computing environment     

Kostas Kalabokidis  Nikolaos Athanasis  Christos Vasilakos  Palaiologos Palaiologou 《International journal of geographical information science》2014,28(3):541-552

Effective wildfire management is an essential part of forest firefighting strategies to minimize damage to land resources and loss of human lives. Wildfire management tools often require a large number of computing resources at a specific time. Such computing resources are not affordable to local fire agencies because of the extreme upfront costs on hardware and software. The emerging cloud computing technology can be a cost- and result-effective alternative. The purpose of this paper is to present the development and the implementation of a state-of-the-art application running in cloud computing, composed of a wildfire risk and a wildfire spread simulation service. The two above applications are delivered within a web-based interactive platform to the fire management agencies as Software as a Service (SaaS). The wildfire risk service calculates and provides daily to the end-user maps of the hourly forecasted fire risk for the next 112 hours in high spatiotemporal resolution, based on forecasted meteorological data. In addition, actual fire risk is calculated hourly, based on meteorological conditions provided by remote automatic weather stations. Regarding the wildfire behavior simulation service, end users can simulate the fire spread by simply providing the ignition point and the projected duration of the fire, based on the HFire algorithm. The efficiency of the proposed solution is based on the flexibility to scale up or down the number of computing nodes needed for the requested processing. In this context, end users will be charged only for their consumed processing time and only during the actual wildfire confrontation period. The system utilizes both commercial and open source cloud resources. The current prototype is applied in the study area of Lesvos Island, Greece, but its flexibility enables expansion in different geographical areas.  相似文献   

Hydro-climatic change,conflict and security     

Giorgos Kallis  Christos Zografos 《Climatic change》2014,123(1):69-82

Climate change is likely to increase the frequency and intensity of water-related hazards on human populations. This has generated security concerns and calls for urgent policy action. However, the simplified narrative that links climate change to security via water and violent conflict is wanting. First, it is not confirmed by empirical evidence. Second, it ignores the varied character and implications of hydro-climatic hazards, the multi-faceted nature of conflict and adaptive action, and crucial intricacies of security. Integrating for the first time research and findings from diverse disciplines, we provide a more nuanced picture of the climate-water-security nexus. We consider findings from the transboundary waters, armed conflict, vulnerability, and political ecology literatures and specify the implications and priorities for policy relevant research. Although the social effects of future hydro-climatic change cannot be safely predicted, there is a good understanding of the factors that aggravate risks to social wellbeing. To reduce vulnerability, pertinent democratic and social/civil security institutions should be strengthened where they exist, and promoted where they are still absent.  相似文献   

Validation of satellite rainfall products for operational flood forecasting: the case of the Evros catchment     

Fotis Fotopoulos  Christos Makropoulos  Maria A. Mimikou 《Theoretical and Applied Climatology》2011,104(3-4):403-414

An extensive validation of two of the most popular and recently upgraded satellite rainfall products, 3B42 and 3B42RT, was performed over the Evros catchment in southeastern Europe using data recorded from January 2000 to April 2009. For conducting this validation study, the Climate Prediction Center's (CPC) ground data were used. The satellite data products were aggregated to daily time series, remapped to spatial resolution of 0.5°, validated against CPC, and intercompared using a variety of statistical indices and coefficients. After the validation process, all three data sets (CPC, 3B42, and 3B42RT) were separately fed in a statistical rainfall?Crunoff model, in order to predict the five major recorded flood events which occurred in the Evros catchment during the last decade. It has been found that post-calibration with ground data, which is present only in 3B42 product, is a necessity for operational flood forecasting and similar studies conducted in areas at mid-latitudes. Knowledge of rainfall events with small intensities is crucial for estimating the total rainfall height and drastically improves the skill of the satellite product.  相似文献   

The Interaction Between Shield,Ground and Tunnel Support in TBM Tunnelling Through Squeezing Ground     

M. Ramoni  G. Anagnostou 《Rock Mechanics and Rock Engineering》2011,44(1):37-61

When planning a TBM drive in squeezing ground, the tunnelling engineer faces a complex problem involving a number of conflicting factors. In this respect, numerical analyses represent a helpful decision aid as they provide a quantitative assessment of the effects of key parameters. The present paper investigates the interaction between the shield, ground and tunnel support by means of computational analysis. Emphasis is placed on the boundary condition, which is applied to model the interface between the ground and the shield or tunnel support. The paper also discusses two cases, which illustrate different methodical approaches applied to the assessment of a TBM drive in squeezing ground. The first case history—the Uluabat Tunnel (Turkey)—mainly involves the investigation of TBM design measures aimed at reducing the risk of shield jamming. The second case history—the Faido Section of the Gotthard Base Tunnel (Switzerland)—deals with different types of tunnel support installed behind a gripper TBM.  相似文献   

Conditions of formation of the Mavrokoryfi high-sulfidation epithermal Cu�CAg�CAu�CTe mineralization (Petrota Graben, NE Greece)     

Panagiotis Christos Voudouris 《Mineralogy and Petrology》2011,101(1-2):97-113

The Mavrokoryfi Cu?CAg?CAu?CTe prospect, northeastern Greece, consists of atypical, high-sulfidation mineralization where precious metals were introduced contemporaneously with advanced argillic alteration from magmatic vapors. It occurs as veins of massive sulfides in zones of silicic and advanced argillic alteration spatially associated with an andesitic lava dome and hyaloclastites. Mineralogical data demonstrate an unusual ore and gangue mineralogy that is compatible with formation under very oxidizing conditions (logfO₂ values of >?31.8) at temperatures of 200°C to 250°C. Oxidizing conditions favored the formation of hypogene lead sulfates (anglesite and barian celestite) instead of galena. Selenian acanthite, cadmian freibergite, and argentian goldfieldite are the main carriers of silver in the deposit and are reported in Greece for the first time. They were deposited at logfS₂ of ?9 to ?7 and logfTe₂ values of ?9 to ?12.5 (250°C). Ag-poor goldfieldite at Mavrokoryfi has up to 3.7 apfu Te and is the most Te-rich goldfieldite yet reported. The mineralization is accompanied by aluminum?Cphosphate?Csulfate minerals of magmatic-hydrothermal origin and an unusual Pb-enrichment. Ore-forming components were likely derived from andesite porphyries.  相似文献   

Ecosystem-based marine spatial management: Review of concepts, policies, tools, and critical issues   总被引：1，自引：0，他引：1  

Stelios Katsanevakis  Vanessa Stelzenmüller  Andy South  Thomas Kirk Sørensen  Peter J.S. Jones  Sandy Kerr  Fabio Badalamenti  Christos Anagnostou  Patricia Breen  Guillem Chust  Giovanni D’Anna  Mike Duijn  Tatiana Filatova  Fabio Fiorentino  Helena Hulsman  Kate Johnson  Aristomenis P. Karageorgis  Ingrid Kröncke  Simone Mirto  Carlo Pipitone  Susan Portelli  Wanfei Qiu  Henning Reiss  Dimitris Sakellariou  Maria Salomidi  Luc van Hoof  Vassiliki Vassilopoulou  Tomás Vega Fernández  Sandra Vöge  Anke Weber  Argyro Zenetos  Remment ter Hofstede 《Ocean & Coastal Management》2011,54(11):807-820

Conventional sectoral management and piecemeal governance are considered less and less appropriate in pursuit of sustainable development. Ecosystem based marine spatial management (EB-MSM) is an approach that recognizes the full array of interactions within an ecosystem, including human uses, rather than considering single issues, species, or ecosystem services in isolation. Marine spatial planning and ocean zoning are emerging concepts that can support EB-MSM. EB-MSM is driven by high-level goals that managers aim to achieve through the implementation of measures. High-level goals and objectives need to be translated into more operational objectives before specific targets, limits and measures can be elaborated.Monitoring, evaluation and adaptation are necessary to ensure that marine management measures are both effective and efficient. Solid monitoring frameworks are the foundation of adaptive management, as they provide the necessary information to evaluate performance and the effectiveness of management actions. Marine protected areas (MPAs) - possibly set up in networks - constitute a key component in EB-MSM policies and practises and have been applied as a cornerstone in conservation of marine biodiversity, management of fish populations, development of coastal tourism, etc. Moreover, MPA experiences have provided methods and concepts (such as zoning) to a wider EB-MSM context. The assignment of values to biophysical features of the marine environment allows the direct assessment of related management choices and may assist EB-MSM.A range of monetary valuation techniques have been proposed to reduce attributes of goods and services to a single metric. However, in the marine environment such an approach is often over simplistic, and thus less reductive techniques may be necessary. Rather than producing a single metric, the results of non-monetary assessments guide policy allowing weight to be given as necessary to potential areas of conflict and consensus.Strategies to take into account climate change effects and geohazard risks in EB-MSM have been applied or proposed worldwide. EB-MSM regimes must be alert to such risks and flexible to account for changes.  相似文献   

Seepage flow around tunnels in swelling rock     

G. Anagnostou 《国际地质力学数值与分析法杂志》1995,19(10):705-724

The swelling phenomenon in tunneling is numerically modelled as a coupled hydraulic-mechanical process. The present communication focuses on the significance of the constitutive seepage flow equations, as well as on the importance of the hydraulic boundary conditions. The observed absence of swelling deformations at the tunnel walls and the crown can be explained as a consequence of varying hydraulic boundary conditions along the excavation boundary. According to the presented numerical results, the non-linearity of the unsaturated flow equations has a decisive qualitative influence on the predicted deformation field.  相似文献   

The influence of tunnel excavation on the hydraulic head     

G. Anagnostou 《国际地质力学数值与分析法杂志》1995,19(10):725-746

In this paper an alternative method is proposed for computing the effect of tunnelling on the piezometric head field during construction. The seepage flow equations, usually formulated in a fixed co-ordinate system are here reformulated within a frame of reference that advances together with the tunnel heading. The governing equations contain the advance rate as an additional parameter, and are solved by the finite-element method. The quasi-steady state (i.e. the steady state in the moving frame of reference) can then be computed in a single step. Selection of a marching scheme in the time domain is, therefore, rendered unnecessary. Thanks to the economy of the proposed method, it has been possible to carry out comprehensive parametric studies, the results of which are presented in a dimensionless form. The applicability of the computational method to poroelastic problems is also addressed.  相似文献   

Application of multivariate statistical procedures on major ions and trace elements in a multilayered coastal aquifer: the case of the south Rhodope coastal aquifer     

Evangelos C. Galazoulas  Christos P. Petalas 《Environmental Earth Sciences》2014,72(10):4191-4205

Multivariate statistical techniques including cluster analysis and principal components analysis were applied on 22 variables consisted of 3 physicochemical parameters, 8 major ions and 11 trace elements. Samples were collected from the south Rhodope multilayered coastal aquifer in north Greece which is facing saltwater intrusion and anthropogenic contamination over the last 35 years. Cluster analysis grouped the variables into five main groups while principal components analysis revealed four distinct hydrochemical processes in the aquifer system, explaining 84.5 % of the total variance between the variables. The identified processes correspond to, saltwater intrusion and subsequent reverse cation exchange, the presence of deep connate groundwater masses, application of fertilizers in shallow wells and anthropogenic contamination with heavy metals nearby an improperly constructed landfill. The wells categorized with the above techniques were grouped and five constituent ratios Na/Cl, (Mg + Ca)/Cl, Ca/(HCO₃ + SO₄), Ca/SO₄ and Ca/Mg were utilized to identify the ones which enable the more accurate distinction between the group cases. The results of stepwise discriminant analysis showed that the calculated classification function can distinguish almost 80 % of groundwater samples with the Na/Cl ratio being the most statistically significant grouping variable. All the aforementioned statistical models managed to successfully identify numerous hydrochemical processes in a complex multilayered aquifer system and to explicitly attribute them for every investigated well, allowing a deeper insight into groundwater chemical characteristics with the use of an optimized smaller number of variables.  相似文献