Changes In Element Concentrations Research Articles

Matrix Effects in Quantitative Analysis of Laser-Induced Breakdown Spectroscopy (LIBS) of Rock Powders Doped with Cr, Mn, Ni, Zn, and Co.

Obtaining quantitative chemical information using laser-induced breakdown spectroscopy is challenging due to the variability in the bulk composition of geological materials. Chemical matrix effects caused by this variability produce changes in the peak area that are not proportional to the changes in minor element concentration. Therefore the use of univariate calibrations to predict trace element concentrations in geological samples is plagued by a high degree of uncertainty. This work evaluated the accuracy of univariate minor element predictions as a function of the composition of the major element matrices of the samples and examined the factors that limit the prediction accuracy of univariate calibrations. Five different sample matrices were doped with 10-85 000 ppm Cr, Mn, Ni, Zn, and Co and then independently measured in 175 mixtures by X-ray fluorescence, inductively coupled plasma atomic emission spectrometry, and laser-induced breakdown spectroscopy, the latter at three different laser energies (1.9, 2.8, and 3.7 mJ). Univariate prediction models for minor element concentrations were created using varying combinations of dopants, matrices, normalization/no normalization, and energy density; the model accuracies were evaluated using root mean square prediction errors and leave-one-out cross-validation. The results showed the superiority of using normalization for predictions of minor elements when the predicted sample and those in the training set had matrices with similar SiO2 contents. Normalization also mitigates differences in spectra arising from laser/sample coupling effects and the use of different energy densities. Prediction of minor elements in matrices that are dissimilar to those in the training set can increase the uncertainty of prediction by an order of magnitude. Overall, the quality of a univariate calibration is primarily determined by the availability of a persistent, measurable peak with a favorable transition probability that has little to no interference from neighboring peaks in the spectra of both the unknown and those used to train it.

Influence of palaeoweathering on trace metal concentrations and environmental proxies in black shales

The mineralogical and chemical compositions of Lower Carboniferous (Tournaisian) marine black shale from the Kowala quarry, the Holy Cross Mountains, Poland, were investigated. This study focuses on disturbances in palaeoenvironmental proxies caused by palaeoweathering, which progressively changed the major and trace element abundances. Palaeomagnetic investigations reveal that the Devonian – Carboniferous succession was weathered during the Permian-Triassic by the infiltration of oxidizing fluids related to karstification following post-Variscan exhumation. The weathering process led to vermiculitization of chlorite, partial dissolution of calcite and replacement of pyrite by hematite and goethite. Moreover, the concentrations of some trace metals, including Co, Cu, Pb, Mo, Ni, As and U, significantly decreased. Consequently, some elemental abundance ratios that are used as environmental proxies, including U/Th, Ni/Co and V/Cr, were altered. Elements that are bound to iron sulphides (e.g., Mo) appear to be especially prone to mobilization by even a lightly weathered black shale. The documented weathering, including changes in elemental concentrations, can potentially create misinterpretations of the original palaeoenvironmental conditions. In addition, the palaeoweathering of the studied samples appears to have substantially changed the carbon, oxygen, nitrogen and molybdenum stable isotope values. The nitrogen and molybdenum stable isotope ratios, in particular, appear to be most sensitive to the effects of weathering and therefore are good indicators of (palaeo)weathering processes. The major cause of these changes is the decay of organic matter and pyrite. For the organic carbon stable isotopes ratios, the main factor that controlls this process appears to be the preferential degradation of labile organic matter. A combination of the total organic carbon (TOC), total sulphur (TS) content, Mo concentration and stable isotope compositions seems to be the most useful for identify (palaeo)weathering. Our results suggest that reductions in TS and Mo in tandem with diminished Mo stable isotope values in the absence of obvious changes to the TOC content provide the most compelling evidence of (palaeo)weathering.

Environmentally assisted cracking resistance of Al–Cu–Li alloy AA2195 using slow strain rate test in 3.5% NaCl solution

The general corrosion and environmental cracking resistances of Al–Cu–Li alloy AA2195 were investigated in 3.5% NaCl environment and compared with those of another high strength alloy AA2219. The general corrosion resistance of these alloys was examined using immersion corrosion and potentiodynamic polarization tests, while the stress corrosion cracking (SCC) resistance was evaluated by slow strain rate test (SSRT) method. The tested samples were further characterized by SEM–EDS and optical profilometry to study the change in corrosion morphology, elemental content and depth of corrosion attack. The reduction in ductility was used as a parameter to evaluate the SCC susceptibility of the alloys. The results indicated that the corrosion resistance of AA2195 alloy was better than that of AA2219 alloy as it exhibited lower corrosion rate, along with lower pit depth and density. However, the SCC index (ɛNaCl/ɛair) measured was greater than 0.90, indicating good environmental cracking resistance of both the alloys. Detailed fractography of the failed samples under SEM–EDS, in general, revealed a typical ductile cracking morphology for both the alloys.

Dynamics of Chemical and Biological Properties of Organically Amended Petroleum Hydrocarbon Polluted Soil as Affected by Incubation Periods

A study was conducted in the Screen house of the Department of Crop, Soil and Pest Management, FUTA Akure to examine the time dynamic trends in soil chemical properties as affected by contamination with petroleum hydrocarbon compounds (PHC) in a 6 months incubation period as affected by organic amendments. The petroleum hydrocarbon compounds used were spent engine oil (SEO), bitumen (BIT) and crude oil (CRO). The organic amendments used were poultry manure and mycorrhizal fungi (Glomus mossae) spores. The respective petroleum hydrocarbon compounds (spent engine oil SEO, bitumen BIT and crude oil CRO) were applied at 2 rates of 0 and 455 ml per pot and 3 levels of organic amendments followed by incubation for six (6) months. Soil samples were collected from each treatment at 0, 2, 4 and 6 months after treatment application for the determination of some chemical properties (pH, organic carbon, N, P, K, Ca and Mg). The time changes in elemental concentrations of soil contamination with petroleum hydrocarbon compounds (SEO, BIT and CRO) showed declining trends in the values of pH, organic carbon and Mg while N-Total, Ca and available P and K rose with time. In general, the nature of the trends (polynomial function as best fit) indicated that the observed responses were not uni-function of a factor but suggest interaction among factors responsible for the breakdown of petroleum hydrocarbon compounds and hence its toxicity to soil chemical properties. The time course of changes in soil chemical properties as affected by petroleum hydrocarbon compounds (PHCs) contamination in soil differed among the PHCs evaluated. The values of the measured soil parameters recorded at the commencement of the experiment and at 2, 4, 6 months after the application of the petroleum hydrocarbon compounds showed declining trends in the values of pH, organic carbon and Mg were obtained. Increasing trends in N-total and available P with time up till the end of the experiment while SEO recording the highest values at 6 months of incubation. Trends of the mean values (highest and lowest values) with respect to treatment showed that CRO had the highest soil pH at 2 and SEO had the lowest at 6 month. SOC increased across treatments with SEO recording the highest value at 2 months of incubation, which was followed by general decline in values with time across the PHCs. The results indicated that PHCs adversely affect soil chemical properties and that addition of organic substances improved chemical properties of the soil following pollution with petroleum hydrocarbon compounds compared with the un-amended soils. Poultry manure in particular performed better compared with mycorrhizal inoculum with respect to improvement of soil chemical properties.

PIXE analysis of stream water following the Mt. Hakone eruption on 30 June 2015 — temporal changes in elemental concentrations over two years

After the 2011 Off the Pacific Coast of Tohoku Earthquake on 11 March, 2011, volcanic activity in Japan was observed to increase. In this study, we use the PIXE method to analyze elemental concentrations in stream water flowing directly from the fumarolic area on Mount Hakone, which erupted on 30 June 2015. Throughout a two-year monitoring period following the eruption, concentrations of 12 dissolved elements were measured. We found that the stream water was strongly acidic. For one year after the eruption, the concentrations of magma-derived elements (S, Cl) and rock-derived elements (Al, Ca, Fe, K, Mg, Mn, and Na), except for Si, showed a clear decreasing trend. These measurements suggest that magmatic activity and fumarolic activity reduced gradually over one year. After this year-long period, elemental concentrations stopped decreasing and instead showed broadly flat levels with sporadic increases and decreases. However, throughout the year immediately following the eruption, the number of volcanic earthquakes was consistently at zero or close to zero. These different indications of volcanic activity suggest that the elemental concentrations in stream water may be more sensitive indicators of small changes in subterranean behavior than of the number of volcanic earthquakes.

The status of the aquatic ecosystem of the Selenga river delta under long-duration low-water conditions

We examine the ecological aspects concerning the status of the surface waters in the delta of the Selenga river for the low-water conditions which have been observed since 1996. The ongoing changes in the most important indicators of the status of the waters in the river delta are assessed on the basis of results of hydrological, hydrochemical and hydrobiological investigations made by these authors in 2013–2015 and with consideration for earlier research efforts. It is established that the low-water conditions resulted in a decrease of the role of the main delta branches, Kharauz and Levoberezhnaya, in streamflow. An increase in the contribution of groundwater in the alimentation of the river led to an increase in concentrations of main ions: for the current low-water period their total content has varied from 119 to 780 mg/L, with a maximum in small delta branches in the wintertime. Changes in concentrations of biogenic elements were recorded: total phosphorus from 10 to 190 μg P/L, mineral phosphorus from 0 to 35 μg P/L, and nitrate nitrogen from 0.01 to 0.81 μg N/L. A minimum of mineral phosphorus compounds and nitrogen was observed at the time of mass development of algae. It is established that the dynamics of organic matter content is determined by changes in hydraulicity, and by the intensity of phytoplankton development. Within the long-term context, a deterioration of water regime and vegetation infill and swamping of shallow delta branches were recorded. The development level of the phytoplankton and changes in its structure point to a progressive eutrophication of the Selenga waters. According to the value of the saprobic index, the quality of the Selenga waters corresponds largely to the category of “moderately polluted” waters (class II and III), and it decreases at low-water periods, especially in shallow delta branches with a high population of cryptophytic algae, to the category of “polluted” waters.

Immobile and mobile elements during the transition of volcanic ash to bentonite – An example from the early Palaeozoic sedimentary section of the Baltic Basin

In order to check the immobility and mobility of elements during conversion of acidic volcanic glass to bentonites in normal marine environments, we studied the composition of three altered volcanic ash layers from the Palaeozoic of the Baltoscandian Region, correlated through different facies. Regular changes in element concentrations in accordance with loss and gain of material during the transformation of volcanic ash indicate that Al, Nb, Ti, Zr, Sn, Pt, Ta, Hf and Th were generally immobile and can be used for the interpretation of source magma and correlation of ash layers. Cd behaves similarly with immobile elements and this can be explained with preservation only of the immobile portion of Cd that is fixed in phenocrysts. In bentonites in shales during the formation of kaolinite, the data indicate small-scale mobility of Al and Cd. In lime muds where K-feldspar forms from volcanic ash, Ta, Hf and Th reveal some small scale mobility. These slightly mobile elements must be used with caution for interpretation of thin ash layers with thicknesses of <1cm. Sc, V, Ga, Y and Rare Earth Elements widely used for the interpretation of bentonites have noticeable mobility and can thus be used only semi-quantitatively or qualitatively in the bulk bentonite.

Segregation of Elements in Continuous Cast Carbon Steel Billets Designated for Long Products

Abstract This article presents research results concerning designation of the scope of segregation of elements by analysing the ingot, designated for hot rolling of long products. The research tests were performed under industrial conditions, during continuous casting production cycle of high carbon steels. From cc ingots with square cross-section of 160 mm samples having the length of 400 mm were collected, out of which two samples were cut up, the so-called templates with the thickness of 20 mm. Segregation of elements was determined based on the quantitative analysis of results performed by using spark spectrometry pursuant to PN-H-04045. Changes in concentrations of elements were analysed along the line, which join the opposite sides of the sample in their half length and pass through the geometric centre of the square cross-section. In the further course of the research study, there was also determined the segregation along perpendicular line up to the surface connecting the core of the cross-section with lateral plane. Designations of element contents were performed at points distanced from each other by approx. 10 mm and situated on the lines. There was found segregation of carbon, sulphur and phosphorus.

Probing Intracellular Element Concentration Changes during Neutrophil Extracellular Trap Formation Using Synchrotron Radiation Based X-Ray Fluorescence.

High pressure frozen (HPF), cryo-substituted microtome sections of 2 μm thickness containing human neutrophils (white blood cells) were analyzed using synchrotron radiation based X-ray fluorescence (SR nano-XRF) at a spatial resolution of 50 nm. Besides neutrophils from a control culture, we also analyzed neutrophils stimulated for 1–2 h with phorbol myristate acetate (PMA), a substance inducing the formation of so-called Neutrophil Extracellular Traps (or NETs), a defense system again pathogens possibly involving proteins with metal chelating properties. In order to gain insight in metal transport during this process, precise local evaluation of elemental content was performed reaching limits of detection (LODs) of 1 ppb. Mean weight fractions within entire neutrophils, their nuclei and cytoplasms were determined for the three main elements P, S and Cl, but also for the 12 following trace elements: K, Ca, Mn, Fe, Co, Ni, Cu, Zn, Se, Br, Sr and Pb. Statistical analysis, including linear regression provided objective analysis and a measure for concentration changes. The nearly linear Ca and Cl concentration changes in neutrophils could be explained by already known phenomena such as the induction of Ca channels and the uptake of Cl under activation of NET forming neutrophils. Linear concentration changes were also found for P, S, K, Mn, Fe, Co and Se. The observed linear concentration increase for Mn could be related to scavenging of this metal from the pathogen by means of the neutrophil protein calprotectin, whereas the concentration increase of Se may be related to its antioxidant function protecting neutrophils from the reactive oxygen species they produce against pathogens. We emphasize synchrotron radiation based nanoscopic X-ray fluorescence as an enabling analytical technique to study changing (trace) element concentrations throughout cellular processes, provided accurate sample preparation and data-analysis.

Seasonal and long‐term changes in elemental concentrations and ratios of marine particulate organic matter

AbstractWhat is the temporal variability of the elemental stoichiometry of marine microbial communities across ocean regions? To answer this question, we present an analysis of environmental conditions, particulate organic carbon, nitrogen, and phosphorus concentrations and their ratios across 20 time series (3–25 years duration) representing estuarine, coastal, and open ocean environments. The majority of stations showed significant seasonal oscillations in particulate organic elemental concentrations and ratios. However, shorter‐term changes contributed most to overall variance in particulate organic matter concentrations and ratios. We found a correlation between the seasonal oscillations of environmental conditions and elemental ratios at many coastal but not open ocean and estuarine stations. C:N peaked near the seasonal temperature minimum and nutrient maximum, but some stations showed other seasonal links. C:N ratios declined with time over the respective observation periods at all open ocean and estuarine stations as well as at five coastal station but increased at the nine other coastal stations. C:P (but not N:P) declined slightly at Bermuda Atlantic Time‐series Study but showed large significant increases at Hawaii Ocean Time‐series and Arendal stations. The relationships between long‐term changes in environmental conditions and particulate organic matter concentrations or ratios were ambiguous, but interactions between changes in temperature and nutrient availability were important. Overall, our analysis demonstrates significant changes in elemental ratios at long‐term and seasonal time scales across regions, but the underlying mechanisms are currently unclear. Thus, we need to better understand the detailed mechanisms driving the elemental composition of marine microbial ecosystems in order to predict how oceans will respond to environmental changes.

Surveying Changes in Sectional Tissue Nutrient Concentrations of Hibiscus acetosella ‘Panama Red’ during Adventitious Root Formation

A study was conducted to observe changes in mineral element concentrations within different sections of leafy stem cuttings of Hibiscus acetosella ‘Panama Red’ (PP20121) during a 21-day propagation period under standard industry propagation conditions. Concentrations of 13 mineral elements were analyzed in leaves, lower stems (below substrate), upper stems (above substrate), and roots at 3-day intervals. Before root emergence (day 0–6), P, K, Zn, Ca, and Mg concentrations decreased in the shoots (including upper stems and leaves), whereas Zn, Ca, and B concentrations decreased in the lower stems. Sulfur increase occurred in lower stems before root emergence. After rooting (day 9–21), N, P, Zn, Fe, Cu, and Ni concentrations decreased in the roots; K, S, B, and Mg concentrations increased. In the lower stems, N, P, K, S, and Zn concentrations decreased, whereas B increased. Potassium concentration decreased in the leaves; P, K, S, and Zn decreased in the upper stems. Calcium and Mg increased in leaves. This study indicates specific nutrients are important in adventitious rooting, and that it is important to analyze rooting as a function of fine-scale temporal measurements and fine-scale sectional measurements.

Whole body-element composition of Atlantic salmon Salmo salar influenced by migration direction and life stage in three distinct populations.

Body-element content was measured for three life stages of wild Atlantic salmon Salmo salar from three distinct Newfoundland populations as individuals crossed between freshwater and marine ecosystems. Life stage explained most of the variation in observed body-element concentration whereas river of capture explained very little variation. Element composition of downstream migrating post-spawn adults (i.e. kelts) and juvenile smolts were similar and the composition of these two life stages strongly differed from adults migrating upstream to spawn. Low variation within life stages and across populations suggests that S. salar may exert rheostatic control of their body-element composition. Additionally, observed differences in trace element concentration between adults and other life stages were probably driven by the high carbon concentration in adults because abundant elements, such as carbon, can strongly influence the observed concentrations of less abundant elements. Thus, understanding variation among individuals in trace elements composition requires the measurement of more abundant elements. Changes in element concentration with ontogeny have important consequences the role of fishes in ecosystem nutrient cycling and should receive further attention.

Surface-Subface Geochemical and Mineralogical Study of Gypcrete in Alexandria Area Central Iraq

Gypsiferous soil deposits (Gypcrete) are weakly consolidate earthy mixture of secondary gypsum, sand and clay. It is formed in arid and semi- arid area with annual precipitation rainfall less than 400mm. These sediments occur in surface and subsurface in region of little rainfall and rapid evaporation. This research deals with the study of gypcrete in Alexandria to improve the mineralogical and geochemical properties of the gypcrete. The gypcrete soil is used as raw material to produce the plaster for building purposes. Three samples of gypcrete were chemically and geochemically analyzed. The common mineral is howed in 0-0.5m Gypsum followed by Calcite in 0-1m and Quartz in 1-1.5m due to leaching and infiltration by rainfall as well as it full the clay Matrix and the voids between soil constituent, therefore soil properties changes with depth and the clay materials increases such as (Al, Na and K oxides) and Gypsum compound decreases (Ca, S and Sr oxides), yet the change in element concentration, takes the same path. This indicate that annual season rainfall is the only factor affecting mineralogy in this arid area and this means that the Gypsum concentration cannot be affected by ground water either increasing or decreasing. This research concerns about mineralogy and element occurrence variation in this material with accordance to their concentration from surface to depth of 1.5 meter.

Changes of risky element concentrations under organic and mineral fertilization

The 28-day incubation experiment was carried out to evaluate the impact of the application of digestate (Dig); digestate with straw (DigSt); pig slurry (Slu) and mineral fertilizer (NPK) on Cd, Cu, Mn and Zn availability, on K&lt;sub&gt;2&lt;/sub&gt;SO&lt;sub&gt;4&lt;/sub&gt;-extractable carbon content and on the soil pH value in long-term contaminated soil. At days three and seven of the experiment, the 0.01 mol/L CaCl&lt;sub&gt;2&lt;/sub&gt;-extractable fractions of Cd, Zn and Mn significantly decreased under organic treatments (Dig, DigSt and Slu) with the most pronounced effect under Dig treatment. The NPK treatment caused the increase of risky element concentrations since day 21 of incubation which was accompanied with pH decrease. The contents of 0.5 mol/L K&lt;sub&gt;2&lt;/sub&gt;SO&lt;sub&gt;4&lt;/sub&gt;-extractable carbon were the highest at day 3 and 7 of incubation in organic treatments. The significant correlations between 0.5 mol/L K&lt;sub&gt;2&lt;/sub&gt;SO&lt;sub&gt;4&lt;/sub&gt;-extractable carbon and CaCl&lt;sub&gt;2&lt;/sub&gt;-extractable metal concentrations showed a close relationship between fresh organic matter added in organic fertilizers and risky element availability, suggesting that newly added labile organic matter can form temporary ligands with risky elements and release them later following its decomposition.

Temporal stability and rates of post-depositional change in geochemical signatures of brown trout Salmo trutta scales.

This study investigates temporal stability in the scale microchemistry of brown trout Salmo trutta in feeder streams of a large heterogeneous lake catchment and rates of change after migration into the lake. Laser-ablation inductively coupled plasma mass spectrometry was used to quantify the elemental concentrations of Na, Mg, Mn, Cu, Zn, Ba and Sr in archived (1997-2002) scales of juvenile S. trutta collected from six major feeder streams of Lough Mask, County Mayo, Ireland. Water-element Ca ratios within these streams were determined for the fish sampling period and for a later period (2013-2015). Salmo trutta scale Sr and Ba concentrations were significantly (P < 0·05) correlated with stream water sample Sr:Ca and Ba:Ca ratios respectively from both periods, indicating multi-annual stability in scale and water-elemental signatures. Discriminant analysis of scale chemistries correctly classified 91% of sampled juvenile S. trutta to their stream of origin using a cross-validated classification model. This model was used to test whether assumed post-depositional change in scale element concentrations reduced correct natal stream classification of S. trutta in successive years after migration into Lough Mask. Fish residing in the lake for 1-3 years could be reliably classified to their most likely natal stream, but the probability of correct classification diminished strongly with longer lake residence. Use of scale chemistry to identify natal streams of lake S. trutta should focus on recent migrants, but may not require contemporary water chemistry data.

Changes in Trace Element Contents and Morphology in Bones of Duck Exposed to Molybdenum or/and Cadmium.

Cadmium (Cd) and high molybdenum (Mo) can lead to adverse reactions on animals, but the coinduced toxicity of Mo and Cd to bone in ducks was not well understood. The objective of this study was to investigate the changes in trace elements' contents and morphology in bones of duck exposed to Mo or/and Cd. One hundred twenty healthy 11-day-old male ducks were randomly divided into six groups and treated with commercial diet containing Cd or/and Mo. On the 60th and 120th days, the blood, excretion, and metatarsals were collected to determine alkaline phosphatase (ALP) activity and the contents of Mo, Cd, calcium (Ca), phosphorus (P), copper (Cu), iron (Fe), zine (Zn), and selenium (Se). In addition, metatarsals were subjected to histopathological analysis with the optical microscope and radiography. The results indicated that Mo and Cd contents significantly increased while Ca, P, Cu, and Se contents remarkably decreased in metatarsals in coexposure groups (P<0.01). Contents of Fe and Zn in metatarsals had no significant difference among groups (P>0.05). Ca content in serum had no significant difference among experimental groups (P>0.05), but P content was significantly decreased in HMo and HMo+Cd groups (P<0.05). Contents of Ca and P in excretion and ALP activity were significantly increased in coinduced groups (P<0.05). Furthermore, osteoporotic lesions, less and thinner trabecular bone were observed in combination groups. The findings suggested that dietary of Cd or/and Mo could lead to bone damages in ducks via disturbing the balance of Ca and P in body and homeostasis of Cu, Fe, Zn, and Se in bones; moreover, the two elements showed a possible synergistic relationship.

Veränderungen der Nährstoffgehalte im Blatt der Rebe (Vitis labrusca L.) auf verschiedenen Unterlagen bei Anbau auf schwerem Lehmboden in Abhängigkeit vom phänologischen Stadium

The present study was conducted to determine the phenological changes in leaf nutrient contents in 10-years Vitis labrusca L. grapes grafted on 140Ru, 5BB and 5C rootstocks. In the experiment, changes of leaf macro and micro element contents from bud burst to post harvest period were investigated in the heavy clay soil conditions. Nutrient contents of leaf blades showed varied depending on the phenological stages and rootstocks (P < 0.01). P, K, Mg and Ca levels of leaf blade exhibited significant differences based on rootstocks and phenological periods between blooming and veraison. While Zn level was obtained sufficient on 5BB of grafted grapevines, it was found to be insufficient in grapevines grafted on 140Ru and 5C rootstocks. In general, grapevines were found insufficient for P, K and Mg nutrients. Total chlorophyll contents of leaves were found at high in the blooming period. Although the highest chlorophyll contents were found in the blooming period, it was determined at the lowest through to harvest. In the study, 5BB rootstock was evaluated to be favorable in terms of nutrient uptake.

The Analysis of Heavy Metal Concentrations in Eggs of Collared Flycatchers, Ficedula Albicollis (Passeriformes, Muscicapidae), and Tits, Parus Major, Parus Caeruleus (Passeriformes, Paridae), in Different Areas of North-Eastern Ukraine

AbstractCollared flycatchers (Ficedula albicollis Temminck, 1815), have more opportunities to accumulate heavy metals due to migration but they are more resistant to contamination in contrast to tits, (Parus major Linnaeus, 1758, Parus caeruleus Linnaeus, 1758). This research aimed to detect concentrations of some trace elements in eggs of the collared flycatcher, great tit and blue tit in different areas. There were found differences in heavy metal concentrations in the eggs among species and study areas. For collared flycatchers there were not established consistent patterns of changes in element concentrations among areas. The highest heavy metal levels were found in tits in samples of egg contents from a forest park (Pb - 3.1410 ± 0.3249, Cu - 19.3290 ± 1.4840, Zn - 66.9612 ± 17.6665, Fe - 249.5513 ± 40.2800, Mn - 6.9032 ± 0.2946, Ca - 8298.3570 ± 0.1080, Sr - 17.6032 ± 0.7512, Ni - 0.5177 ± 0.0220). The lowest concentrations were found in egg contents of tits in Hetmanskyi National Nature Park (Cu - 4.3492 ± 0.2079, Fe - 44.6647 ± 0.2627, Mn - 1.3194 ± 0.2374, Ca - 998.7001 ± 0.0006, Ni - 0.2443 ± 0.0439, Cr - 0.1466 ± 0.0424). The results indicate that heavy metals accumulated differently in shells and contents of eggs of collared flycatchers and tits in each of the study area. Some of microelements (zinc, mercury, iron, manganese, selenium and iodine) in small amounts are required for normal growth and development of birds. Heavy metal concentrations in egg shells and egg contents of all species did not exceed permissible levels.

Investigation of microstructure and thermal stability of pulsed plasma processed chromium ferritic-martensitic steels

This paper presents results of the microstructural evolution and thermal stability of the promising Russian ferritic-martensitic steels (EP 823, EP 900, EK 181 and ChS 139) for the nuclear and fusion application after surface modification by high temperature pulsed plasma flows (HTPPF) treatment. Investigations of microstructure, topography and elemental content changes associated with irradiation by nitrogen plasma with energy density 19-28 J/ cm2 and pulse duration 20 μs were carried out. Changes in microstructure and elemental content occurring in the modified surface layer were characterized by means of scanning electron microscopy (SEM) and X-ray microanalysis (EDS and WDS). It was shown that independently of initial microstructure and phase composition, HTPPF treatment of ferritic- martensitic steels leads to formation of ultrafine homogeneous structure in the near surface layers with typical grain size ∼100 nm. Results of microstructure investigations after annealing during 1 hour demonstrates significant thermal stability of nanostructure formed by HTPPF treatment.

Active Sphagnum girgensohnii Russow Moss Biomonitoring of an Industrial Site in Romania: Temporal Variation in the Elemental Content.

The moss-bag transplant technique was used to investigate the kinetics of the accumulation of 38 elements in Sphagnum girgensohni moss samples in the highly polluted municipality of Baia Mare, Romania. The moss samples collected from the unpolluted Vitosha Mountain Natural Reserve, Bulgaria, were analyzed after 1, 2, 3, and 4 months of exposure, respectively. The ANOVA method was used to assay the statistical significance of the observed changes in elemental content, as determined by neutron activation analysis. The content of Zn, Se, As, Ag, Cd, and Sb increased steadily, while that of physiologically active K and Cl, as well as Rb and Cs, decreased exponentially. The study showed that an adequate application of the moss transplant technique in an urban environment should consider the exposure time as a critical parameter, since particular elements are depleted in the moss at sites with high atmospheric loading of metals.