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Following the rapid technology development on smart and electronic textiles, research on textile antennas has rapidly emerged during the last decade due to their numerous applications in the health and safety sectors. Integrated electronic components in textile structures enables the development of new products and services for commercial and tactical applications. Correspondingly, antenna systems that are either embedded in clothing or developed using textile materials are needed. However, the inherent impairments of antenna operability when integrated into garments (i.e. bending and crumbling due to the user’s mobility) make the development of textile antennas a challenging task. Another important issue is the operation of antennas in close vicinity to the human body, which can be modeled as a large volume with electrical properties different than those of air. In this paper, we report a linear spiral antenna design with a sufficiently large bandwidth to support wireless communications in a multitude of available networks, and also the potential to be used for body scanning and medical imaging through microwave transmission and scattering measurements.

International audience; A short history of the application of NAA in the characterization of archaeological materials at the National Center for Scientific Research 'Demokritos', Athens, is presented. NAA was first applied in archaeology in 1974 at the Radioanalytical Laboratory, and since 1989 has been one of the primary analytical techniques of the 'Demokritos' archaeometry programme. A case study is also presented, concerning chemical patterning of the black-on-red Neolithic pottery class from Macedonia. Four chemical groups were identified, each corresponding to a different area of production. It is shown that this standardized concept of pottery technology and style was spread out within at least eastern Macedonia.

The source identification of trace elements emitted into Athens (Greece) atmospheric environment has been studied by the Enrichment Factor (EF) and by Principal Component Analysis (PCA). The prevailing wind direction is related to EF data in order to identify the possible pathways of trace elements, in the Athens basin. As gas pollutants and trace elements could be emitted from the same source, the possible relation between these two groups is studied by PCA and correlation relations. According to EF data, the trace elements Fe, Sm, Th, Co, Sc, Cr and K have a crustal origin while the elements Zn, As, Sb, Ag, Br result of anthropogenic pollution. The study of the prevailing wind direction showed that the existing geophysical channel in the northern area of Athens basin could be a pathway for the entrance of Fe, La, Sm, Th, Co, Cr, Na and Ag into Athens atmosphere. On the contrary, the sea breeze could be a potential cleaner of the atmosphere from the same elements. Six source factors were resolved by PCA for all the Athens area explaining the 90% of the total variance. They could nominated as soil dust, central heating, movement of cars, car tires, car break abrasion and sea breeze. After the application of PCA and the linear regression model, the concentration of atmospheric ozone shows to have a positive significant correlation with Na and Zn and a negative significant correlation with As, Br, Ce, Co, Cr, Fe, La, Sb, Sc, Sm. A possible explanation of the mechanism for the decrease of atmospheric ozone concentration in relation to trace metals is given according to the existing literature data.

In this paper, the relation between the trace element content in air particulates and solar meteorological data in the atmospheric environment of Athens, Greece, was studied. For this purpose, Sm, Br, As, Na, K, La, Ce, Cr, Ag, Sc, Fe, Zn, Co, Sb, Th were determined by INAA in respirable aerosols collected during winter 1993-1994. The results showed that the average cloudiness, sunshine, and the total solar radiation (sun and sky) on a horizontal surface, (3 variables) have no relation with trace element variation. However, diffuse solar radiation (sun and sky) on a horizontal surface seems to have statistically significant relationship with some of the trace element variation. It forms a single component with some trace elements after the application of the factor analysis. The increase of the same solar variable in the Athens City center, is one of the factors which cannot permit the emission of trace elements in the atmospheric environment from dust soil and car tires.

Two different instrumental neutron activation analysis (INAA) methods were applied to characterize chemically 74 ceramic roof tile samples, found in the town of Pella, Greece and dated back to the Hellenistic Period (3rd century B. C.). The samples were first analyzed for 17 elements with a 4 hour irradiation and two counts and then re-analyzed for 9 elements with a 1 minute irradiation and two counts of short-lived radioisotopes. The results of both methods were very similar, showing the validity of the rapid INAA method (1 min irradiation) in the study of ancient ceramics. All samples were divided into 4 chemical groups, each one representing a different tiling.

Neutron activation analysis (NAA) is a very sensitive and accurate multielement analytical method that is widely applied to the investigation of environmental and archaeological problems. The first part of this paper is a review of pollution studies of toxic trace elements in sediments, seawater and marine organisms of Saronikos Gulf, Greece by NAA. The second part of this paper is a review of provenance studies based on minor and trace element research in ancient ceramics, obsidian, flint, limestone, marble and lead by Instrumental NAA, performed at the NCSR Demokritos.

The excavations at Mandalo in Macedonia, Greece, have produced a remarkably high number of obsidian objects, dated to the late Neolithic and early Bronze Age. Eleven of these samples were analysed by instrumental neutron activation for 19 minor and trace elements, in order to determine their provenance. It was found that all Neolithic and one Bronze Age samples came from the Carpathian 1 source, while another Early Bronze Age sample came from the Demenegaki source in Melos. The overlap between Carpathian and Melian obsidian distributions is evidence for interactions of ancient Macedonia with central Europe and the Aegean. Also, according to this finding, the Carpathian distribution pattern has now been extended for another 400 km to the south, from Vinca to Mandalo.

Instrumental Neutron Activation Analysis (NAA) has been applied for the determination of Ag and Sb in water column, sediment cores, and two marine organisms from Saronikos Gulf, Greece. Higher levels of Ag and Sb were found in the water column and cores from polluted areas of the Gulf as compared to those from unpolluted areas. No significant differences of Ag and Sb were found in the two marine organisms from all areas of Saronikos Gulf.

This paper presents the results on 20 minor and trace elements of a wide analytical programme — based on neutron activation and statistical analysis — which deals with the chemical characterization of pottery from the Cycladic islands and Crete, during the Bronze Age (Cycladic period), with particular reference to Akrotiri on Thera. Multivariate analysis of the neutron activation data showed that the majority of the pottery found in Akrotiri was locally made, by one type of clay. This in connection with the local style that Akrotiri had introduced, supports the idea of an autonomous development. Contacts with neighbouring islands were also confirmed.

Thirty elements were determined by two INAA methods in sediment core samples from N. Saronikos Gulf, Greece, and the results were subjected to multivariate analysis. This procedure resulted in the separation of samples into chemical groups that were environmentally meaningful and sufficient to (a) distinguish among different pollution sources; (b) trace the routes and the extent of pollution in sediments; and (c) define the least affected areas representing the geochemical background. The principal components analysis of the analytical data for 18 selected elements revealed that, among the elements determined in this study, the most discriminating were As, Sb, Ag, Ca, Au, Zn and the rare earth elements (REE).

Neutron activation analysis, in combination with multivariate analysis of the generated data, was used for the chemical characterization of prehistoric pottery from the Greek islands of Thera, Melos (islands with similar geology) and Crete. The statistical procedure which proved that Theran pottery could be distinguishable from Melian, is described. This discrimination, attained for the first time, was mainly based on the concentrations of the trace elements Sm, Yb, Lu and Cr. Also, Cretan imports to both Thera and Melos were clearly separable from local wares.

Melt spun ribbons of Pr 2 Fe 7 B 3 alloys develop coercivities up to 2.0 T upon annealing between 620 and 660° C. Mossbauer spectra and X-ray powder diagrams show that the annealed samples consist of two phases, Pr 2 Fe 14 B and PrFe 4 B 4 . The minor loop coercivity is strongly dependent on the magnetizing field.

Neutron activation analysis (NAA) methodology was applied for the certification of eight trace elements (As, Co, Cr, Cu, Hg, Mn, Se, and Zn) in a plankton reference material (CRM 414) prepared by the BCR of the Commission of the European Communities. Average concentrations (µg/g dry wt) and standard deviations found in plankton for the eight trace elements were as follows: As 6.29 ± 0.19, Co 1.37 ± 0.05, Cr 23.7 ± 0.56, Cu 27.1 ± 0.88, Hg 0.29 ± 0.02, Mn 285 ± 4.1, Se 1.62 ± 0.10, and Zn 114 ± 3.4. All values found were to be in very good agreement (0.5%–8.1%) with certified values.

The partitioning of Co, Cr, Fe, Sc and Zn into three fractions (reducible by acidified hydroxylamine hydrochloride, oxidizable by acidified hydrogen peroxide, and the residual after the previous extractions) of Saronikos Gulf surface sediments was determined by using a sequential extraction technique. The metal concentrations were determined by Instrumental Neutron Activation Analysis. With the exception of Sc, the metal content in the reducible and oxidizable fractions increases in the polluted sediments near the Athens Sewage Outfall (ASO) and a Fertilizer Plant (FP). In the non-polluted sediments, the residual fraction is the most important carrier for all metals examined. Oxidizable Cr and Zn correlate well with the organic carbon content of the sediments, but the reducible fraction (mainly Fe/Mn hydroxides) is the most important sink for Co, Cr, Fe and Zn in the polluted sediments near the ASO. The pyrite-rich wastes from the FP are influencing the geochemical partitioning of the metals examined in the sediments in front of the FP and, partially, in the sediments near the ASO.

A simple and sensitive radiochemical neutron activation analysis (RNAA) method has been developed for the simultaneous determination of mercury and selenium in biological materials. The radiochemical procedure is based upon the digestion of irradiated samples with sulphuric and nitric acids followed by subsequent extractions of mercury and selenium into toluene, first of mercury from 7.5 M H2SO4-0.01M HBr media and after of selenium from 7M H2SO4-1 M HBr media. After washing of the organic phases with similar media, the mercury bromide was back-extracted into 0.034M EDTA in 5% aqueous ammonia and the selenium bromide into 0.14M H2O2 in aqueous solution. The197Hg and the75Se were counted on a Ge(Li) detector. The precision and accuracy of the method was checked by analysing NBS Standard Reference Materials: orchard leaves and bovine liver.

The effect of purifying, mixing and firing of clays on trace element concentration was systematically investigated using instrumental neutron activation analysis. Eight different clays from two sites in Crete were used together with sherds found around several kilns near the sites. Trace element analysis showed that the extent to which the concentration changes after purification and firing depends on the initial particle size and chemistry of the clay. The calcite concentration plays an essential role in this. An application is made using roof tiles found at the excavation of the ancient city of Pella in Macedonia.

Seventeen trace elements (As, Ce, Co, Cr, Cs, Eu, Fe, Hg, Hf, La Lu, Rb, Sb, Sc, Sm, Yb and Zn) have been determined by Instrumental Neutron Activation Analysis in sediments from the upper Saronikos Gulf, Greece. It was found that the discharge of industrial and domestic wastes in the Keratsini and Elefsis bays of the upper Saronikos Gulf had led to elevated concentrations of all toxic and other trace elements determined over at least 100 km2 of seafloor. Increases above natural level range from 2 fold for rare earths to 200 fold for arsenic.

The domestic and industrial waste water from most of the greater Athens, Greece area is discharged into shallow water at the upper end of the semi-enclosed Saronikos Gulf. The lack of circulation and excess organic matter has led to the formation of a rapidly expanding sludge field. Black anoxic sediments high in organic carbon now cover almost 9 sq km of sea floor and contain high concentrations of heavy metals. Maximum increases above background values range from 22× for mercury, 1500× for arsenic, 1200× for chromium, to 3000× for zinc. The principal sources of metals are 1) a fertilizer factory, 2) the Athens sewer outfall, and 3) the industries in eastern Elefsis Bay.

Instrumental neutron activation analysis has been applied for the determination of 20 minor and trace elements (As, Ce, Co, Cr, Cs, Eu, Fe, Hf, La, Lu, Na, Rb, Sb, Sc, Sm, Ta, Tb, Th, Yb and Zn) in two groups of potsherds which had been excavated at two different sites of Greece, the islands of Thasos (Group A) and Delos (Group B). A good agreement for all the elements examined between the pottery specimens of Groups A and B was found. The matching in chemical composition between the stylistically related potteries of Group A (Thasos) and Group B (Delos) provides strong support for the archaeologist's hypothesis that the two groups of potsherds belong to the same major group of “melian” pottery.

Instrumental neutron activation analysis and X-ray techniques have been applied for the determination of 24 major, minor and trace elements (Al, Ca, Cc, Co, Cr, Cs, Eu, Hf, Fe, K, La, Lu, Na, Rb, Sb, Sc, Si, Sm, Ta, Tb, Th, Ti, Yb and Zn) in three or four different groups of vases (Protocorinthian, Thapsos Class, Late Geometric Corinthian and Aigion Crater). A close agreement for all elements examined between the pottery specimens of all groups was found. The matching in chemical composition of the four groups of vases strongly suggests the same origin for all of them.

Antimony(III) can be extracted rapidly and quantitatively into benzene from a 10 M H2SO4–0.03 M HBr system. The extracted antimony bromide has an antimony to bromine ratio of 1:3. Under the above optimum conditions for extraction of antimony, the behaviour of 35 other elements was studied; As3+, Ge4+, Se4+, and Sn2+ were extracted almost quantitatively, and the percentage extraction of Hg2+, Bi3+, and Te4+ was 74.1%, 10% and 5.5% respectively. The extraction of the elements into benzene from a 5 M H2SO4–0.01 M KI system was also investigated, A comparison of the two systems is given.

Non-destructive neutron-activation analysis is used for determining chlorine in paper-pulp. Numerical data have been obtained for bleached and unbleached paper-pulps of different types and origins. The sensitivity of this method is 100 ppm for an irradiation time of 30 min and a neutron flux of 6 x 10(10) neutrons.cm(-2).sec(-1) and 10 ppm for an irradiation time of 1 min and a neutron flux of 2 x 10(12) neutrons.cm(-2).sec(-1). In both cases the amount of chlorine that can be determined depends on the presence of the interfering elements manganese and sodium in the paper-pulp. The time required for a complete analysis, after irradiation, is 5 min.

Concentrations of zinc, cobalt, selenium, rubidium, bromium, and gold have been determined by neutron activation analysis in 18 placental and 6 liver tissue samples at birth. Their respective mean concentrations +/- standard deviations (parts per million) were 58 +/- 10, 0.060 +/- 0.036, 1.90 +/- 0.41, 14.0 +/- 3.5, 26.9 +/- 14.3, and 0.31 +/- 0.14 in placenta, and 651 +/- 257, 0.156 +/- 0.077, 4.52 +/- 1.96, 9.2 +/- 3.7,11.2 +/- 4.1, and 0.12 +/- 0.06 in liver tissue. Thus, we observed that the mean concentrations of essential trace elements (zinc, cobalt, and selenium) were significantly higher in liver than in placenta, whereas the nonessential trace elements (rubidium, bromium, and gold) were found in significantly higher concentrations in placenta than in liver tissue.

Provenance of marble is a very difficult but most challenging problem. Before 1954 marble characterization was based primarily upon visual observation and only petrographic techniques were used as important supplements to assign marble provenance. Today several analytical techniques are used for marble identification which have been recently reviewed by Norman Herz (Herz, 1985). They all have advantages and limitations. Quite often more than one analytical techniques are used in provenance investigation of marbles (Moens et al. 1986).

The ceramic specimens examined in this study were taken from roof tiles of the Hellenistic period found in Pella, northern Greece. They represent five chronologically successive tilings of two buildings. Neutron activation analysis results showed that a different clay was used for the construction of each roof. Results of technological analysis indicate a consistency in the manufacture of the tiles, except for the first tiling which seems to be technologically different and more advanced.

Neutron-activation analysis has been used to determine magnesium, strontium and nickel in water from eleven Greek lakes. The elements were separated by an isolation procedure (taking up to 30 minutes); the magnesium and strontium were determined by γ-spectrometry, and the nickel by β-co-incidence counting. The ranges found were 11 to 31 p.p.m. of magnesium, 0·02 to 1·12 p.p.m. of nickel and 0·07 to 0·48 p.p.m. of strontium.

A rapid and simple neutron-activation analysis method has been developed for the determination of copper in plant leaves. Irradiated samples are dissolved in a mixture of fuming nitric acid, 70% perchloric acid and concentrated sulphuric acid in the presence of copper carrier solution. The copper in the resulting solution is extracted as copper cupferronate into chloroform and back-extracted into concentrated ammonia solution. The copper is precipitated as sulphide with 3% aqueous thioacetanude solution and the precipitate is dissolved in nitric acid. The induced activity of copper-64 in the resulting solution is counted with a 400-channel analyser. The photopeak of the annihilation energy of copper-64 at 0.51 MeV is compared with that of a copper standard processed in the same manner. After counting, the chemical yield of the separated copper is found by re-irradiating aliquots of the copper nitrate solution and comparing the induced activity of coppcr-66 at 1.04 MeV with that of another standard processed in a similar manner. The time required to complete the analysis, including the second irradiation and all radioactivity measurements, is about 25 min. The accuracy of the method was checked by analysing a biological standard of known copper content. The proposed method was successfully applied to the determination of copper in the leaves of 10 different plants (copper content 4-30 ppm).