Sledovi metalurške dejavnosti na keramičnih fragmentih

Fragments of two clay objects, supposedly used in early metallurgy, were examined by the method of X-ray fluoroscence and proton-inducted X-ray emission. The inner surface of one object was enriched in copper iron, sulphur, and traces of arsenic. According to these elements, the object may be related to the copper metallurgy based on sulphide ores.Kose dveh keramičnih predmetov, ki so jih domnevno uporabljali v zgodnji metalurgiji, smo pregledali z metodama rentgenske fluorescence in protonsko vzbujenih rentgenskih žarkov. Na notranji površini enega od predmetov smo našli povečane koncentracije bakra, železa, žvepla in sledove arzena. Ti elementi kažejo, da lahko predmet povežemo z metalurgijo bakra iz sulfidnih rud

Genetička, biokemijska, hranjiva i antimikrobna svojstva šipka (Punica granatum L.) uzgojenog u Istri

This study characterises the genetic variability of local pomegranate (Punica granatum L.) germplasm from the Slovenian and Croatian areas of Istria. The bioactive components and antioxidant and antimicrobial properties of ethanol and water extracts of different parts of pomegranate fruit were also determined, along with their preliminary nutritional characterisation. Twenty-six different genotypes identified with microsatellite analysis indicate the great diversity of pomegranate in Istria. The pomegranate fruit ethanol extracts represent rich sources of phenolic compounds (mean value of the mass fraction in exocarp and mesocarp expressed as gallic acid is 23 and 16 mg/g, respectively). The ethanol extracts of pomegranate exocarp and mesocarp showed the greatest antimicrobial activity against Candida albicans, Candida parapsilosis, Rhodotorula mucilaginosa, Exophiala dermatitidis and Staphylococcus aureus, and the same water extracts against S. aureus and Escherichia coli. To the best of our knowledge, this study represents the first report of the characterisation of pomegranate genetic resources from Istria at different levels, including the molecular, chemical, antimicrobial and nutritional properties.U ovom je radu opisana genetička raznolikost germplazme šipka (Punica granatum L.) s područja slovenskog i hrvatskog dijela Istre. U etanolnim i vodenim ekstraktima različitih dijelova ploda šipka pronađeni su bioaktivni spojevi, te su ispitana njihova antioksidacijska i antimikrobna svojstva i preliminarno određena hranjiva svojstva ekstrakata. Dvadeset i šest različitih genotipova utvrđenih analizom mikrosatelita upućuju na veliku raznolikost šipka u Istri. Etanolni ekstrakti ploda šipka predstavljaju bogat izvor fenolnih spojeva (srednja vrijednost masenog udjela, izraženog kao galna kiselina, bila je 23 mg/g u egzokarpu i 16 mg/L u mezokarpu). Etanolni ekstrakti egzokarpa i mezokarpa šipka imali su snažan antimikrobni učinak na sljedeće vrste: Candida albicans, Candida parapsilosis, Rhodotorula mucilaginosa, Exophiala dermatitidis i Staphylococcus aureus, dok su vodeni ekstrakti egzokarpa i mezokarpa uspješno suzbijali rast bakterija S. aureus i Escherichia coli. Prema našim spoznajama, ovo je prva karakterizacija genetičkih izvora šipka iz Istre, koja obuhvaća molekularna, kemijska, antimikrobna i hranjiva svojstva plodova

60Co in Cast Steel Matrix: a European Interlaboratory Comparison for the Characterisation of New Activity Standards for Calibration of Gamma-ray Spectrometers in Metallurgy

International audience; Two series of activity standards of Co-60 in cast steel matrix, developed for the calibration of gamma-ray spectrometry systems in the metallurgical sector, were characterised using a European interlaboratory comparison among twelve National Metrology Institutes and one international organisation. The first standard, consisting of 14 disc shaped samples, was cast from steel contaminated during production ("originally"), and the second, consisting of 15 similar discs, from artificially-contaminated ("spiked") steel. The reference activity concentrations of Co-60 in the cast steel standards were (1.077 +/- 0.019) Bq g(-1) on 1 January 2013 12h00 UT and (1.483 +/- 0.022) Bq g(-1) on 1 June 2013 12h00 UT, respectively

Beryllium-7 activity concentration trends in Serbia and Slovenia

Beryllium-7 is a natural radionuclide used as a tracer of the stratospheric-tropospheric exchange. Its abundance in the surface air is expected to change as the temperatures in the atmosphere increase. To investigate the temporal trends of the beryllium-7 activity concentrations and temperature, we apply spectral analysis to time series from three sampling sites: Belgrade in Serbia, and Ljubljana and Krško in Slovenia. The sites lie close to the 45 ºN parallel, with Krško approximately 400 km and Ljubljana around 500 km west of Belgrade. Between January 1991 and December 2019, the air filter samples were collected using air samplers; a monthly composite sample was formed and analysed by gamma spectrometry. We use monthly mean temperature records from the European Climate Assessment & Dataset, the Republic Hydrometeorological Service of Serbia for Belgrade, and the Slovenian Environment Agency for the sites in Slovenia. In the spectral analysis decomposition, we look into a term called trend that represents the overall growth (increase or decrease) in the data records. The trend is calculated using a linear fit. All three sites show 1) positive temperature trends, however statistically insignificant (at the 95 % confidence level), and 2) statistically significant beryllium-7 activity concentration trends of 2.26 %/year, 1.13 %/year, and 0.50 %/year in Belgrade, Ljubljana, and Krško, respectively. The results confirm our initial hypothesis–over the 28 investigated years, the beryllium-7 activity concentrations increase in the surface air. On the other hand, the non-significant temperature rise in our records suggests that within our method, the temporal resolution of one month is insufficient for obtaining a statistically significant temperature trend

The effect of cultivation practices on agronomic performance, elemental composition and isotopic signature of spring oat (Avena sativa L.)

The present study investigated the effects of cultivation practices on grain (oats) yield and yield components, such as straw yield, harvest index, thousand kernel weight, and plant lodging. In addition, multi-element composition and isotopic signature (δ(13)C, δ(15)N) of the oat grains were studied. The spring oat cultivar ‘Noni’ was grown in a long-term field experiment during 2015–2020, using three management practices: control without organic amendment, incorporation of manure every third year and incorporation of crop residues/cover crop in the rotation. Synthetic nitrogen (N) (0, 55, 110 and 165 kg/ha) was applied during oat development in each system. Multi-element analysis of mature grains from two consecutive years (2016 and 2017) was performed using EDXRF spectroscopy, while stable isotope ratios of carbon (C) and nitrogen (N) were obtained using an elemental analyzer coupled to an isotope ratio mass spectrometer (EA/IRMS). The results show how cultivation practices affect yield components and isotopic and elemental signatures. Increasing the N rate improved both the oat grain and straw yields and increased susceptibility to lodging. The results show how the elemental content (Si, Ca, Zn, Fe, Ti, Br and Rb) in the oat grains were influenced by intensification, and a noticeable decrease in elemental content at higher N rates was the result of a dilution effect of increased dry matter production. The mean δ(15)N values in oat grains ranged from 2.5‰ to 6.4‰ and decreased with increasing N rate, while δ(13)C values ranged from −29.9‰ to –28.9‰. Based on the δ(15)N values, it was possible to detect the addition of synthetic N above an N rate of 55 kg/ha, although it was impossible to differentiate between different management practices using stable isotopes

Elemental composition of wheat, common buckwheat, and tartary buckwheat grains under conventional production

The elemental composition of cereal and pseudocereal grain is believed to significantly affect the portions of the minerals supplied for particular human populations. Therefore, care needs to be taken to improve the availability of the essential elements and to decrease unwanted metal accumulation in edible plant parts. In the present study, we have investigated the element accumulation in the grain of wheat (Triticum aestivum L.), common buckwheat (Fagopyrum esculentum Moench), and tartary buckwheat (Fagopyrum tataricum (L.) Gaertn.), harvested from the same field under conventional grain production. Soil and grain element compositions were analysed using energy dispersive X-ray fluorescence spectrometry and total reflection X-ray fluorescence spectrometry. The wheat grain shows significantly higher (p<0.05) higher element concentrations than both of the buckwheat species tested. The contents of elements in 100 g grain were higher than the concentrations listed in the literature for wheat and buckwheat flours, which indicates significant losses of elements during milling and polishing. Concerns are raised due to the high and unwanted metal accumulation in wheat and buckwheat. The data indicate that both of these buckwheat species accumulate less metal contaminants when compared to wheat