Institute of Materials Science

Highly crystalline superparamagnetic Fe3O4 nanoparticles coated by polyvinylpyrrolidone
(PVP) were prepared by simultaneous thermal decomposition of ferrous and
ferric inorganic salts in polyethylene glycol (PEG) with molecular weight 200. The magnetic
particles have a diameter in the range of 8-15 nm, and after exchange with citric acid
diammonium salt, they transform into very stable super hydrophilic colloidal solutions. The
presence of magnetite phase was confirmed using powder X-rays diffraction (XRD) and
Mössbauer spectroscopy, while thermogravimetric analysis and FT-IR spectroscopy confirmed
the presence of PVP or citrate anions on the nanoparticles surface. The magnetic properties
revealed superparamagnetic behavior, with the composite material showing a saturation
magnetization up to 57 emu/g. The Fe3O4 nanoparticles prepared by this modified polyol process
are suitable for biomedical applications because of the biocompatibility of citrate anions.
Magnetic hyperthermia experiments in neutral water solutions shows that the particles induce
fast heating rates with specific absorption rate (SAR) values which reached 57.53 W/gFe, when
the concentration of iron is 11.2 mgFe/ml

As a former part of the great Roman Empire, Slovenia has many archaeological sites featuring buildings and objects entirely or partly constructed from marble whose provenance is doubtful. In Slovenia, the most probable source of such marble is the Pohorje Mountains. For the purpose of supporting further provenance studies, these marbles are fully scientifically characterized. The techniques used are petrographic and geochemical analysis, stable isotope ratio analysis and EPR spectroscopy. The results show that the Pohorje marbles are highly heterogeneous in both their isotopic and geochemical parameters as well as grain sizes. The parameters of the different Pohorje marble outcrops are compared between themselves and with the parameters of known ancient quarries in the Mediterranean and Austria. The use of a multi-technique approach with combined parameters allows the best possible discrimination.a rcm_476 177..190

Mortar that was used in building as well as in conservation and restoration works of wall paintings have been analysed isotopically (δ 13 C and δ 18 O) in order to evaluate the setting environments and secondary processes, to distinguish the structural components used and to determine the exact causes that incurred the degradation phenomena. The material undergoes weathering and decay on a large proportion of its surface and in depth, due to the infiltration of water through the structural blocks. Mineralogical analysis indicated signs of sulphation and dissolution/recrystallisation processes taking place on the material, whereas stable isotopes provided information relative to the origin of the CO 2 and water during calcite formation and degradation processes. Isotopic change of the initial δ 13 C and δ 18 O in carbonate matrix was caused by alteration of the primary source of CO 2 and H 2 O in mortar over time, particularly by recrystallisation of calcite with porewater, evaporated or re-condensed water, and CO 2 from various sources of atmospheric and biogenic origin. Human influence (surface treatment) and biological growth (e.g. fungus) are major exogenic processes which may alter δ 18 O and δ 13 C in lime mortar.

Northern Greece has many archaeological sites featuring buildings and objects entirely or partly constructed from marble whose provenance is doubtful. In Northern Greece, the most probable source of such marble is the Rhodope Mountains. For the purpose of supporting further provenance studies, these marbles are fully scientifically characterized. The sampling took place in several ancient quarries which were on trade routes of Hellenistic, Roman or Byzantine settlements. Trade of marble in N. Greece is proved to have been equally important as in S. Greece, comparing the qualitative marble of Thassos with the best marbles of the south (e.g. Paros, Naxos etc.). The techniques used are petrographic and geochemical (microscope, X-Ray diffraction patterns, Scanning Electron Microscope) methods and stable isotope ratio analysis (13C and 18O). The use of a multi-technique approach with combined parameters allows the best possible discrimination. This scientific investigation both supplements the isotopic database and proves that in N. Greece people used also imported marbles.

The provenance question of the marbles used for making the sarcophagi of local production of Thessaloniki in the Roman period had been posed by archaeologists in the past. The hypothesis was that the material came mainly from the quarries of Thassos Island. This paper presents the scientific analysis of 23 characteristic samples from selected sarcophagi at the Museum of Thessaloniki, using three different techniques: electron paramagnetic resonance (EPR) spectroscopy, stable isotope analysis and maximum grain size measurements, plus in-situ examination. New combinations of parameters were used in order to resolve fully the provenance of all samples. The results showed that the vast majority of the objects were indeed made in Thassian marble but from three different quarries, namely Vathy/Saliara (dolomitic marble), Aliki (calcitic marble) and Acropolis/Phanari (calcitic marble). The calcitic marbles from Aliki and to a lesser degree from Acropolis/Phanari are met in all the basic types of sarcophagi (framed type, plain type, garland sarcophagi). The use of the better quality and snow-white dolomitic marble from Vathy/Saliara quarries is relatively restricted and is often found in works that are above the average regarding the quality of their workmanship. In addition, two sarcophagi were made in Pentlelic marble and one in Proconnesian. The scientific analysis results provide a good confirmation of the archaeological estimates and, furthermore, the conclusions constitute henceforth a secure basis for the study of the entire sculptured works of Thessaloniki.

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 δ 18 O and δ 2 H. The measured stable isotope ratios range from − 9.9‰ to − 6.9‰ for δ 18 O and from − 67.50‰ to − 46.5‰ for δ 2 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.

The geochemical conditions that are responsible for the formation of "Chalastraion nitron" in the basin of Lake Pikrolimni (Northern Greece) were investigated in this study. The goal of the study is to confirm Pliny's description: "at Clitae in Macedonia it is found in abundance the best, called soda of Chalestra…" The ionspecific interaction model based on Pitzer's equations showed that the lake brine samples are saturated versus carbonate-bicarbonate sodium and sodium-chloride-sulfate minerals. The results of individual X-Ray Diffraction (XRD) analyses on the evaporative deposits showed that the salts consist mostly of trona, burkeite, thenardite and halite confirming Pliny's description.

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 carbonatebicarbonate sodium (Natron, Trona) minerals. Pikrolimni brines lie on an evaporation trend given by dD ¼ 4.74& and d 18 O ¼ À13.38&. Both isotopic values (d 18 O and dD) 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 Nachloride 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.

Geochemical characterization of two landfills, one closed and the other still active, both located near Komotini (Thrace, Greece), has been carried out. The aim was to provide an integrated and reliable methodology for a rapid assessment of the real impact of a municipal solid waste landfill, in the main environmental matrices (air and water) of the surrounding areas. The chemical (CO 2 , CH 4 , CO, H 2 , N 2 , and O 2 + Ar) and isotopic characterization (δ 13 C (CO2) and δ 13 C (CH4)) of landfill gas and chemical

Carbon and hydrogen isotopes Fractionation factors 103 gas samples collected at 7 different Italian landfills have analyzed to define their chemical (CO 2 , CH 4 , N 2 and O 2 + Ar,) and isotopic (δ 13 C CO 2 , δ 13 C CH 4 , δ 2 H CH 4) composition. Chemical analysis was carried out by means of gas chromatography (Thermal Conductivity Detector-TCD and Flame Ionization Detector-FID), while isotopic parameters were analyzed by means of gas mass spectrometry. The N 2 /(O 2 + Ar) and CH 4 /CO 2 ratios have been utilized in order to obtain a primary classification of the samples. Following this approach, 7 groups, corresponding to different redox conditions and various degrees of interaction with air, have been individuated. This classification has been compared with isotopic indications. Isotopic contents (δ 13 C CO 2 and δ 13 C CH 4) have been processed to investigate fermentation processes by means of statistical data processing of fractionation factor (α), consisting in partitioning technique. This approach leads to a new definition of the fractionation factor (α) limits that define the domains of existence of major fermentation processes. These limits correspond to the maximum value expected for CO 2 absorption and/or CH 4 massive oxidation processes (α = 1.049), and to the minimum fractionation factor expected for CO 2 biological reduction pathway (α = 1.067). Obtained results indicate that it is possible to assume which fermentation processes take place in LFG generation by combining information derived from the interpretation of chemical and isotopic data. Anyway, it is worth to note that the complexity of LFG generation processes, involving several matrices and a multitude of microbial associations, cannot be unwisely investigated just by chemical analysis or by a single isotopic parameter.

World Health Organisation (WHO) guideline value for boron is 0.5 mg/l. The drinking-water standard of the European Community [11] (EC Directive, 1983) is twice the value recommended by WHO, but still boron concentrations in many ground-and surface waters in Greece exceed this value, rendering such water unacceptable according to the European standards. Boron is biologically an essential element, but at high concentrations is toxic to plants (above approximately 1 mg/l in irrigation water) and probably to humans. Because of this potential toxicity and the need of implementation of EU regulation on national level, the study of the boron levels in both ground-and surface water is of great significance for water management. In Greece, a significant number of thermal, mineral and superficial water springs, especially in Northern Greece and in islands, present high boron values. Nevertheless, such ground waters or borehole water with high temperature and high boron content are frequently used for irrigation and drinking purposes, and could therefore have an antagonistic effect on crop yield and health. In order to study the boron contamination and to elucidate the origin of B, we collected a number of hot and fresh waters all over Greece. The relatively high concentrations of boron in groundwater became a major problem in the study areas. Some million m 3 of groundwater are rendered unusable due to the high boron content. The need of significant quantities of high quality water is an important issue due to rapid

This paper reviews stable isotopic data concerning spring water in Greece in addition to new measurements (59); their spatial variations are investigated in order to provide basic information and identify the locally significant parameters that affect stable isotopic distributions. The area of interest was partitioned into eight sections according to geographical location and climatic characteristics. Local spring water lines (LSWLs) are more or less consistent throughout the country. High-resolution isoscape maps of spring freshwater (Cl − < 200 ppm; and T < 25 • C) for both δ 18 O and δ 2 H were generated, revealing several interesting features such as the effect of Pindos ridge, a strong climatic signal in southern Greece and indications of seawater intrusion in flat coastal areas.

In Plasma Physics laboratory of NCSR "Demokritos" the plasma chemistry method has been used for the restoration and conservation of metallic archaeological objects during the last decades. The obtained experience had led us to conclude that plasma parameters and different status of treated objects are so specific, so as to become unique. In the present paper the theoretical and experimental results of our laboratory are summarized. A treatment table of plasma parameters is given, which claims to be useful for the conservators. It is obvious that this treatment table needs to be completed and extended, so that it meets the uniqueness of each artifact. A theoretical study and the treatment of a variety of iron objects are presented.