Seasonal variations of naturally occurring radionuclides and 137cs in the leaves of deciduous tree species at sites of background radioactivity levels

Activity concentration of natural radionuclides and 137Cs were studied in leaves of the deciduous trees. In the spring and autumn season, leaves were collected in the area of normal background radiation levels represented by city parks in a multi-year period (2002-2012). Measurements by means of gamma-ray spectrometry showed 226Ra and 210Pb seasonal accumulation in leaves, while 238U and 235U could be detected only in autumn. Difference between seasons was not found significant for 40K and 137Cs. The study of radionuclides transfer factors was conducted by analyzing its relationships with basic soil properties at the beginning and the end of the vegetation period. © 2019, Editura Academiei Romane. All rights reserved

Seasonal variations of naturally occurring radionuclides and 137cs in the leaves of deciduous tree species at sites of background radioactivity levels

Activity concentration of natural radionuclides and 137Cs were studied in leaves of the deciduous trees. In the spring and autumn season, leaves were collected in the area of normal background radiation levels represented by city parks in a multi-year period (2002-2012). Measurements by means of gamma-ray spectrometry showed 226Ra and 210Pb seasonal accumulation in leaves, while 238U and 235U could be detected only in autumn. Difference between seasons was not found significant for 40K and 137Cs. The study of radionuclides transfer factors was conducted by analyzing its relationships with basic soil properties at the beginning and the end of the vegetation period. © 2019, Editura Academiei Romane. All rights reserved

Maceral and biomarker composition of lignite lithotypes - Implications on palaeoenvironment and grindability properties

Maceral and biomarker composition of different lignite lithotypes: matrix-coal, pale yellow xylite-rich coal, dark yellow xylite-rich coal, brown xylite-rich coal, mineral-rich coal and dopplerite originating from the Upper Miocene (“Pontian”) Kostolac Basin, Serbia was studied in detail. The objective was to establish the sources of organic matter and to determine palaeoenvironmental conditions which resulted in formation of different lignite lithotypes. Moreover, the influence of lignite lithotypes on grindability properties has also been assessed. Mineral-rich coal was formed in topogenous fresh water peat mire with open water areas. Formation of matrix coal was performed in reed march. The peatification of pale yellow- and dark yellow xylite proceeded in dry forest swamp. Brown xylite was formed in wet forest swamp, whereas dopplerite could have formed during transition of wet forest swamp into bush mire. Contents of liptinites, inertinites, gelinite, mineral matter, sesquiterpenoids, hopanoids and n-alkanes have positive impact on Hardgrove Grindability Index (HGI), whereas total huminites, telohuminite and total organic carbon content, as well as retene/2-methyl, 1-(4’-methylpentyl), 6-isopropylnaphthalene ratio exhibited negative influence on HGI

The potential of biomarkers to distinguish Lower and Middle Miocene lignites from the coal-mining district of Lusatia

The organic geochemical study of Lower and Middle Miocene lignites from the coal-mining district of Lusatia in eastern Germany has been performed. Since the samples showed a uniform and low degree of maturity (0.32-0.37 %Rr), it can be considered that maturity has no significant impact on biomarker distributions. Therefore, the objective of the study is to examine the potential of biomarkers to distinguish Lower and Middle Miocene lignites in relation to sources and depositional environment of organic matter (OM). The biomarker patterns show relatively similar compositions in studied lignites, indicating no significant change in palaeclimate from Lower to Middle Miocene. Middle Miocene lignites are characterized by more pronounced variations of biomarker signatures due to the more pronounced fluctuation of water-level and/or palaeo-wildfires. Peatification was performed under stable water-level. The main differences between Middle and Lower Miocene coals are expressed by higher dehydroicetexane content, Paq index, the tetracyclic/tricyclic diterpanes ratio and non-hopanoid triterpenoids content, as well as by lower content of hopenes and fernenes in the latter one. Mentioned results indicate decreasing contribution of Cupressaceae and emergent macrophytes, associated with increased input of Pinaceae, angiosperms and ferns to the precursor OM of Middle Miocene samples in comparison to Lower Miocene samples

Maturation and isotopic changes of individual hydrocarbons in lignite lithotypes through diagenesis and early catagenesis

Maturation and isotopic changes of individual hydrocarbons in lignite lithotypes through diagenesis and early catagenesis were studied. The maturity ratios based on biomarkers and alkylaromatics which showed the best applicability were determined. Intensity of observed changes of maturity ratios decreases in the following order: mineral-rich coal > matrix coal > xylite-rich coal, indicating that mineral matter, which is dominated by clays in all lithotypes, plays an important role in the isomerisation of polycyclic biomarkers and aromatic compounds. Carbon isotopic signatures of n-C25 and n-C27 alkanes, as well as δ13C values of phenathrene and cadalene are very close in studied range of maturity, confirming that isotopic signatures are useful tracers for alteration products of biological molecules. Long-chain homologues of n-alkanes exhibit slight enrichment in 12C with increasing maturity, whereas almost no change is detected in δ13C of short-chain n-alkanes. Negligible enrichment in 13C of aromatic compounds is observed during maturation

Petrographical and organic geochemical study of the lignite from the Smederevsko Pomoravlje field (Kostolac Basin, Serbia)

Three Upper Miocene (Pontian) lignite seams are present in the Smederevsko Pomoravlje field (Kostolac Basin, Serbia). The origin of their organic matter (OM), the characteristics of the depositional environment and certain utilisation properties have been evaluated based on petrographic data, bulk organic geochemical parameters, biomarker patterns and their isotope signatures. Moreover, results of isotopic analysis were used for the investigation of the influence of diagenetic aromatisation on delta C-13 signatures of biomarkers. The studied lignites are typical humic coals. The OM of lignites is derived from woody vegetation and herbaceous peat-forming plants, with a strong prevalence of the former. The peat-forming vegetation is dominated by decay resistant conifers, including gymnosperm families Cupressaceae, Taxodiaceae, and Pinaceae. Angiosperms occurred in lower amounts. Minor contribution of ferns, fungi and emergent aquatic macrophyta to the biomass is also evident. Chemoautotrophic- and heterotrophic bacteria played an import role during diagenesis. Diagenetic alterations, associated with change in the number of carbon atoms, influence delta C-13 ratios. Diagenetic aromatisation of di- and non-hopanoid triterpenoids is accompanied with C-13 depletion, whereas aromatisation of hopanoids displays the opposite trend. Peatification proceeded in a fresh water environment under variable, anoxic to slightly oxic redox conditions. The lowermost coal seam III accumulated in a topogenous fresh water peat mire with open water areas, which changed occasionally into a wet forest swamp. This resulted in the deposition of mineral-rich coal. The characteristics of lignite in coal seam II are similar to those of coal seam III. This is supported also by generally similar delta C-13 values of individual biomarkers. Coal seam I is dominated by xylite-rich coal, formed under mesotrophic to ombrotrophic conditions. Rapid flooding of the bogs stopped peat growth in all three coal seams. The ratios of ring-A-degraded and non-degraded aromatic diterpenoids and non-hopanoid triterpenoids, proposed in this study, as well as degree of aromatisation of these biomarkers, reflect changes in the water table. Calorific values of the samples indicate that they meet basic requirements for utilisation in the thermal power plants. None of the lignite samples is suitable for coal briquetting, whereas, based on petrographic data, lignite from coal seam I possesses certain potential for fluidized bed gasification

Petrographical and biomarker study of lignite lithotypes and sublithotypes of xylite-rich coal (Kolubara Basin, Serbia)

Invited lectur

The Effects ofAronia melanocarpaJuice Consumption on the mRNA Expression Profile in Peripheral Blood Mononuclear Cells in Subjects at Cardiovascular Risk

Foods and food products that contain polyphenols are proposed to modulate risk of cardiovascular disease. The aim of this three-arm, crossover, randomized, double-blind, placebo-controlled intervention study was to examine the impact ofAronia melanocarpajuice (AMJ), high-polyphenol (AMJ treatment, 1.17 g/100 mL polyphenols) and low-polyphenol (dAMJ treatment, 0.29 g/100 mL polyphenols) dose, on the transcriptome in peripheral blood mononuclear cells (PBMC) of 19 subjects at cardiovascular risk. Transcriptome data were obtained by microarray. Bioinformatic functional annotation analysis was performed on both the whole transcriptome datasets and the differentially expressed genes (DEGs). Expression of selected DEGs was validated by RT-qPCR. Administration of AMJ and dAMJ treatments during the two consecutive four-week treatment periods had additive effects on PBMC transcriptome profiles, with the most pronounced and specific effect noticed for AMJ in the last treatment period (TP3) of the trial. Between the high-dose and low-dose treatments in TP3, there was a multitude of overlapping DEGs and DEG-enriched biological processes and pathways, which primarily included immunomodulation and regulation of cell proliferation/death. Increased expression ofTNF,IL1B,IL8,RGS1,OSM, andDUSP2in TP3 was confirmed by RT-qPCR. The results suggest the immunomodulatory effects of prolonged habitual consumption of polyphenol-rich aronia juice in individuals at cardiovascular risk

Characterisation of lignite lithotypes from the "Kovin" deposit (Serbia) - Implications from petrographic, biomarker and isotopic analysis

Four lignite lithotypes (matrix coal, xylite-rich coal, mixture of matrix and mineral-rich coal and mixture of matrix and xylite-rich coal), originating from the Kovin deposit, were investigated in detail. The paper was aimed to determine the main maceral, biomarker and isotopic (delta C-13) characteristics of investigated lithotypes. Based on these results the sources and depositional environment of organic matter in 4 lithotypes were established. These samples were also used as substrates for investigation of the influence of diagenetic alteration on delta C-13 signatures of biomarkers, as well as for assessment of the most convenient utilization for each lithotype. The investigated lithotypes differ in accordance with the composition of huminite macerals. Xylite-rich coal notably distinguishes from other lithotypes beacuse of the highest content of conifer resins vs. epicuticular waxes. The mixture of matrix and mineral-rich coal is characterised by the greatest contribution of algae and fungi and the most intense methanotrophic activity at the time of deposition. In all coal lithotypes diagenetic aromatisation influenced isotopic composition of individual biomarkers. Xylite-rich coal has the poorest grindability properties. However, this coal lithotype is the most suitable for fluidized bed gasification, whereas the mixture of matrix and mineral-rich coal has the lowest applicability for this process. The calorific value decreases in order: xylite-rich coal gt matrix coal gt mixture of matrix and xylite-rich coal gt mixture of matrix and mineral-rich coal. The increase of organic carbon content and calorific value is controlled by the increase of contribution of wood vegetation vs. herbaceous peat-forming plants, as well as by stability of water table during peatification