General Secretariat for Research and Technology

Athens, Greece

General Secretariat for Research and Technology

Athens, Greece
SEARCH FILTERS
Time filter
Source Type

Dotsika E.,Institute of Materials Science | Poutoukis D.,General Secretariat for Research and Technology | Kloppmann W.,Bureau de Recherches Géologiques et Minières | Guerrot C.,Bureau de Recherches Géologiques et Minières | And 2 more authors.
Applied Geochemistry | Year: 2010

The groundwater B concentration in Mesozoic karst, Neogene and alluvial aquifers in the West part of Chalkidiki province in Central Macedonia, Greece reaches 6.45mgL-1, which exceeds the limit of 1mgL-1, set by the European Union for drinking water. The high B contents have been detected in this area, not only near the shoreline, where seawater intrusion occurs, but also in the inland part of the basin. Multi isotope (2H, 18O, 34S, 18O(SO4), 11B, 87Sr/86Sr) data from borehole and thermal water springs allow identification of the possible B sources. The B dissolved in groundwater in the Chalkidiki area is mainly geogenic. The low δ11B values, 0-1‰, similar to those of thermal fluids from continental geothermal fields, and the low Cl/B ratio compared to seawater both indicate a geothermal origin for B and reflect deep circulation and interaction with igneous rocks. The 87Sr/86Sr ratio also indicates that the deep-aquifer granodiorite is the predominant rock source of Sr, while the shallow limestone unit has negligible effects on the dissolved Sr budget in these thermal karst waters which O and H isotopes show to be of meteoric origin. The main source of high B in borehole water is mainly mixing with B-rich geothermal water. The mixing between geothermal water and water from the Neogene aquifer is also reflected by isotopic contents of SO4. © 2010 Elsevier Ltd.


Dotsika E.,Greek National Center For Scientific Research | Zisi N.,Greek National Center For Scientific Research | Zisi N.,Aristotle University of Thessaloniki | Tsoukala E.,Aristotle University of Thessaloniki | And 3 more authors.
Quaternary International | Year: 2011

Bones and teeth samples of Ursus ingressus from Loutra Arideas Cave (Greece) were used to determine the diet of this extinct species and to reconstruct the palaeoclimatic conditions. The age range of the fossil layers is from 32. ka BP to a maximum of 38. ka BP (radiocarbon dating). The method used was the isotopic analysis of carbonate bioapatite of fossil cave bear (U. ingressus) and brown bear (Ursus arctos) bone and tooth fragments, as well as water samples from springs of the Pindos area, the modern bear habitat. Several possible effects that may affect the isotopic composition of apatite were investigated, including age, sex, tooth type and diagenesis. The comparison of isotopic values of Greek U. ingressus to other Pleistocene Ursidae species in Europe, exhibit more positive and more variable δ13C values. These positive values are attributed mainly to diet, to bear physiology (differences among species) and to climate conditions. The diet of U. ingressus apparently was based mainly on vegetable matter, however with a variable component of animal protein. The variation observed in the δ18O values of U. arctos tooth enamel samples were attributed to environmental conditions, and through the spring waters isotopic gradient for the region of Northeastern Pindos, to differences in the bear's habitat elevation. Assuming similarity of the metabolism of modern and fossil bear species and incorporating only the effect of drinking water on the isotopic composition of body water, an equation has been derived that could be used to provide palaeoclimatic information. © 2011 Elsevier Ltd and INQUA.


Dotsika E.,Greek National Center For Scientific Research | Lykoudis S.,Institute of Environmental Research and Sustainable Development | Lykoudis S.,University of Patras | Poutoukis D.,General Secretariat for research and Technology
Global and Planetary Change | Year: 2010

This paper reviews all available stable isotopic data concerning precipitation and spring water in Greece, from the 1960s until today. Spatial variability is investigated in order to provide basic information and identify the locally significant parameters that affect isotopic distributions. The area of interest was partitioned into eight sections according to geographical location and climatic characteristics. The distance of the station from the sea and the altitude are the main factors imprinted in the isotopic signature of precipitation. Local meteoric water meteoric line (LMWL) for precipitation and spring water were calculated for each section and for Greece as a whole. Precipitation LMWLs differ from the Global Meteoric Water Line (GMWL) in various ways across Greece. Elevated deuterium excess values are observed, probably due to water vapour originating from the Aegean or the Mid-eastern Mediterranean. Spring LMWLs are more or less consistent throughout the country. Furthermore, a high resolution map of precipitation and freshwater spring (Cl- < 200 ppm and T < 25 °C) δ18O reveals several interesting features such as an orographic shadow effect induced by the Pindos Mountains, a strong climatic signal in southern Greece and a local city-microclimate effect around Athens. © 2009 Elsevier B.V. All rights reserved.


Dotsika E.,Greek National Center For Scientific Research | Tzavidopoulos I.,Greek National Center For Scientific Research | Poutoukis D.,General Secretariat for Research and Technology | Raco B.,CNR Institute of Geosciences and Earth Resources | And 2 more authors.
Quaternary International | Year: 2012

The origin of Pikrolimni water was investigated in this study, using stable isotopes, to confirm Pliny's description that "chalastraion nitron" was produced in the basin of Lake Pikrolimni (Northern Greece). Lake Pikrolimni is located in the basin of Kilkis plain, northern Greece, formed in a shallow depression. Lake Pikrolimni is not fed by any major river, and the hydrography of the area shows that no perennial streams enter the lake directly. In the past, the major source of water to the lake was ground water. Today the dominant inflow to Lake Pikrolimni is meteoric water. The meteoric origin of the water is one of the necessary geochemical conditions that are indispensable and responsible for the formation of carbonate-bicarbonate sodium (Natron, Trona) minerals. Pikrolimni brines lie on an evaporation trend given by δD=4.74‰ and δ 18O=-13.38‰. Both isotopic values (δ 18O and δD) increase with salinity, which in turn varies considerably with flooding and evaporation. In dry seasons, part of the lake is desiccated and the margins are locally covered by salts, including Na-carbonate-bicarbonate minerals, Na-sulfate and Na-chloride minerals. These minerals are submitted to repeated wetting and drying cycles under alkaline and strong evaporating conditions. This salt dissolution is reflected in Cl/Br ratios of Pikrolimni water. © 2011 Elsevier Ltd and INQUA.


Papaefthymiou S.,National Technical University of Athens | Tzevelekou T.,Hellenic Research Center for Metals | Antonopoulos A.,Hellenic Research Center for Metals | Gypakis A.,General Secretariat for Research and Technology
International Journal of Structural Integrity | Year: 2016

Purpose: During steel plate and long-product production, numerous imperfections and defects appear that deteriorate product quality and consequently reduce revenue. The purpose of this paper is to provide a practical overview of typical defects (surface and internal) that occur and their root causes. Design/methodology/approach: The data presented here derive from the quality department and from more than 50 technical reports of ELKEME S.A. on the last decade's production of steel making companies STOMANA S.A. and SIDENOR S.A., with emphasis on the defects occurred in some of the products of the Bulgarian plant. Stereoscopic observations of surface defects, light optical metallography, and scanning electron microscopy with EDS represent the most used techniques to characterize defected macro-/micro-areas and microstructures. Findings: In general, the most commonly encountered defects from semi-finished (billets, blooms, and slabs) and final (round bar and plate) steel products are as follows: network cracks, porosity, gas holes, shrinkage, shell, slivers, casting powder entrapment, ladle slag entrapment, other non-metallic inclusions, low hot ductility, centerline segregation cracking, macro- and micro-segregation, and mechanical defects (scratches, transverse cracks, and seams). Practical implications: External and internal quality improvement can reduce the production cost (Euro/ton). Social implications: Improvement of the quality of industrial plates and long products increases the safety of the further-produced constructions and systems such as bridges, cranes, heavy equipment, automobile parts, etc. Originality/value: Root cause analysis and categorization of the most commonly encountered defects can pave the way to production process improvements that directly affect final product quality and the overall per ton production cost. The benefits of this work obviously affect all steel producers/processers, and also society through the safety increase achieved by the quality improvement in the steel products used in constructions and automobile parts. © Emerald Group Publishing Limited.


Raco B.,CNR Institute of Geosciences and Earth Resources | Dotsika E.,CNR Institute of Geosciences and Earth Resources | Dotsika E.,Institute of Materials Science | Cerrina Feroni A.,CNR Institute of Geosciences and Earth Resources | And 2 more authors.
Journal of Geochemical Exploration | Year: 2013

This study investigates the chemistry (major and minor elements) and the stable isotopic composition of water (δ18O and δ2H) and carbon in dissolved inorganic carbon (δ13CDIC) in domestic bottled waters collected on the Italian market.The hydrogen and oxygen isotope ratios of 52 samples of bottled water range from -13.8% to -5.5%, for δ18O and from -99% to -36%, for δ2H. This observed isotopic variability of water (δ18O and δ2H) falls within and spans most of the normal range for Italian meteoric waters suggesting that bottled water isotope ratios preserve information about the water sources from which they were derived. This investigation helped also to determine the natural origin of bottled water, and to indicate differences between the natural and production processes. The production process may influence the isotopic composition of waters. No such modification was observed for sampled waters.For identifying the origin of CO2 in waters, natural source or added exogenous CO2 of industrial origin, the 13C/12C ratio in the dissolved inorganic carbon (DIC) of carbonated bottled water is analyzed. The δ13C and δ18O, in DIC, range from -21% to 0.8% and from -25.5% to -7.7% respectively. The isotopic compositions of DIC (1.5 to -7%) of natural sparkling Italian waters indicate that an endogenous CO2 from the deep zones of earth's crust is the origin of the gas in these waters. In still waters grouping the δ13CDIC values indicates mixing of shallow and deeper mineral water in the aquifer and interrelations between soil CO2 and the water-rock interaction. Moreover δ13CDIC values in bottled waters are in accordance with the δ13C values of the aquifers from which they are pumped out.The isotope ratio data assure that the isotopic fingerprint can be used for the authentication of bottled waters and for the certification of the source of bottled water products, and also, as a tool of characterizing an increasingly important component of the human diet. In addition, the carbon isotopic methods applied, can be used for distinguishing the origin of carbon dioxide in the bottled water for regulatory and consumer control applications.Finally, authentication and identification of CO2 origin, is an important and growing challenge to organism in certifying the quality of bottled waters and is a critical in ensuring that bottled water production does not damage the water resources. © 2012 Elsevier B.V.


Raco B.,CNR Institute of Geosciences and Earth Resources | Dotsika E.,CNR Institute of Geosciences and Earth Resources | Dotsika E.,Greek National Center For Scientific Research | Poutoukis D.,General Secretariat for Research and Technology | And 2 more authors.
Food Chemistry | Year: 2015

Stable isotopes have been applied to determine the origin assignment and verify the geographical provenance that is considered important characteristics of wine products both for consumers and the international regulations, of wines. Stable isotope analyses of 18O/16O, D/H and 13C/12C ratio for the detection of origin and of adulteration in wine are discussed in this study. The δ13C analysis of ethanol and wines water δ18O underlines the importance of the photosynthetic pathway and the environmental conditions of wine. Also we discuss the main factors that are responsible for the differentiation of the oxygen isotope ratios of wine water. Data interpretation demonstrated the efficacy of δ18O analysis not only in the wine but also in grape berries, preferably if the determination of the δ18O value is employed together with the determination of the δ2H isotope content of wine, for the detection of the geographical origin of wine. © 2014 Elsevier Ltd. All rights reserved.


Dotsika E.,Institute of Materials Science | Poutoukis D.,General Secretariat for Research and Technology | Raco D.,CNR Institute of Geosciences and Earth Resources | Psomiadis D.,Institute of Materials Science
Journal of Geochemical Exploration | Year: 2010

Bottled waters are an increasingly significant product in the human diet. In this work, we present a dataset of stable isotope ratios for bottled waters sampled in Greece. A total of 25 domestic brands of bottled still waters, collected on the Greek market in 2009, were analysed for δ18O and δ-H. The measured stable isotope ratios range from δ9.9% to δ6.9% for δ18O and from δ67.50% to δ46.5% for δ-H. Comparison of bottled water isotope ratios with natural spring water isotope ratios demonstrates that on average the isotopic composition of bottled water tends to be similar to the composition of naturally available local water sources, showing that bottled water isotope ratios preserve information about the water sources from which they were derived and suggesting that in many cases bottled water should not be considered as an isotopically distinct component of the human diet. This investigation also helped to determine the natural origin of bottled water, and to indicate differences between the natural and production processes. The production process may influence the isotopic composition of waters. No such modification was observed for sampled waters in this study. The isotopic methods applied can be used for the authentication of bottled waters and for use in the regulatory monitoring of water products. © 2010 Elsevier B.V.


Dotsika E.,Greek National Center For Scientific Research | Poutoukis D.,General Secretariat for Research and Technology | Raco B.,CNR Institute of Geosciences and Earth Resources
Journal of Geochemical Exploration | Year: 2010

A geochemical survey on the thermal fluids released by the volcanic/geothermal system of Methana Peninsula and Loutraki area was undertaken. The Loutraki area is found in the southern part of Athens and the Methana volcano in the north-eastern part of Peloponnesus, which is characterized by high salinity waters. Chemical and isotopic contents were used for the investigation of the origin of thermal water, for the estimation of the mixing process between meteoric, magmatic and sea water involved in the deep geothermal systems and for the evaluation of the deep aquifer temperature. The chemical and isotopic data of the thermal Cl-rich water springs of Methana suggest that they are fed by thermal water mixed with local groundwater and seawater respectively. The parent hydrothermal liquid is a mixture of local groundwater (∼ 43%), seawater (∼ 34%) and arc-type magmatic water (∼ 23%). The chemical and isotopic data of the thermal HCO 3-rich water springs of Loutraki samples indicate a purely meteoric origin. Assessments from chemical and isotopic geothermometer applied on the thermal waters springs suggest the probable existence of a deep geothermal reservoir of middle enthalpy (150 °C) a Methana and low enthalpy (80 °C) in Loutraki area. However, the contribution of marine solutions to the geothermal fluids of Methana and Loutraki area is one of the main cases for the disturbance of the chemical and isotopic geothermometers rendering these calculated temperatures questionable. © 2010 Elsevier B.V. All rights reserved.


PubMed | Greek National Center For Scientific Research, Massa spin off srl, CNR Institute of Geosciences and Earth Resources and General Secretariat for Research and Technology
Type: | Journal: Food chemistry | Year: 2014

Stable isotopes have been applied to determine the origin assignment and verify the geographical provenance that is considered important characteristics of wine products both for consumers and the international regulations, of wines. Stable isotope analyses of (18)O/(16)O, D/H and (13)C/(12)C ratio for the detection of origin and of adulteration in wine are discussed in this study. The (13)C analysis of ethanol and wines water (18)O underlines the importance of the photosynthetic pathway and the environmental conditions of wine. Also we discuss the main factors that are responsible for the differentiation of the oxygen isotope ratios of wine water. Data interpretation demonstrated the efficacy of (18)O analysis not only in the wine but also in grape berries, preferably if the determination of the (18)O value is employed together with the determination of the (2)H isotope content of wine, for the detection of the geographical origin of wine.

Loading General Secretariat for Research and Technology collaborators
Loading General Secretariat for Research and Technology collaborators