Trace element content in fish otoliths in relation to age and size

Fish otoliths could serve as storage sites of certain elements of biological and/or radioecological importance.The elements caesium, cobalt, iron, selenium and silver have been determined in otoliths of the pelagic fish Scomber japonicus colias collected from three sampling areas of the Aegean Sea, by neutron activation analysis and γ-spectroscopy.The distribution pattern of the elemental composition of the otoliths has been correlated with biometrical variables. It has been found that in general the content of the studied elements decreases with increasing age.     

Environment and biology of the Kara Sea: a general view for contamination studies

The recent revelation that over the past 30 years there has been a history of dumping waste including high-level radioactive wastes in the shallow Kara Sea has caused wide-spread concern. The potential impact of these contaminants and other non-nuclear pollutants in the Arctic ecosystem and on human health need to be assessed and, thus, a better insight gained on radioecological processes in cold waters. The present paper proposes a general view on the biology and the environment of the Kara Sea, as a basic tool for the experimental and modelling assessments of the impact of these contaminants.     

Discharge of biogenic substances with river runoff in Selenga basin

Averaged many-year measurement data on the concentrations of mineral forms of biogenic elements are analyzed, and their total concentrations in the rivers of Selenga, Chikoi, Khilok, Uda, Dzhida, and Temnik are evaluated. The monthly variations of the concentrations of major biogenic substances are characterized, and their ratios within a year are determined. Characteristics of river water runoff and biogenic substance concentrations are used to evaluate their within-year discharge by rivers. Characteristic variations in the ratios between the total and mineral forms of biogenic elements discharged by rivers have been revealed. It is established that the share of mineral components in the total input into the Selenga delta N_tot and P_tot are 82 and 22%, respectively.     

Sediment profiles of less commonly determined elements measured by Laser Ablation ICP-MS

Anthropogenic influences on trace element profiles in dated sediments from estuaries have been often documented, with the vast majority of studies focusing on a short list of high-abundance trace elements. Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS) provides a new approach that minimizes sample preparation and contamination while yielding data on a much larger list of elements simultaneously. We present concentrations and enrichment factor profiles for 22 elements at a locality that is 50 km southeast of Baltimore, the principal industrial city on Chesapeake Bay. Samples representing deposition over almost the entire 20th century were obtained from two archived cores collected 20 years apart. The following elements exhibit profiles consistent with a strong anthropogenic influence, i.e. enrichment after 1920 followed by decline after ca.1980, possibly reflecting increased regulatory efforts: Mn, Co, Cu, Zn, Ag, Cd, In, Sn, Sb, Te, Tl, Pb and Bi. As expected, the redox-sensitive elements: Mo, Re and U have similar profiles to one another. Previously, the potentially hazardous elements, Ag, In, Sb, Te, Tl and Bi, have been measured only rarely in estuarine sediments and never in Chesapeake Bay. Our discovery that their profiles track those of well-known pollutants underscores a need to investigate their sources, transport and biogeochemical behavior. Several rarely determined trace elements, Ga, Ge and Nb, exhibit trendless profiles, as do the major elements, Ti and Fe.     

Volcanic ash as a factor in the generation of radioecological conditions in Kamchatka part II. The radiogeochemical properties of environmental components

An area where fresh volcanic ash has fallen was found to have concentrations of Th and U that exceed the background values by factors of 270 and 32, respectively, for natural waters and by factors of 35 and 6 for plants. The soils and bottom deposits were not enriched in Th and U after a single ashfall; however the Th/U ratio decreased in these natural media relative to the background values, indicating a genetic affinity with young ashes where the concentration of highly mobile (relative to thorium) uranium is higher compared with older ashes. For areas far from active ashfalls, where the soils were formed on acid ash, we found higher background concentrations of Th and U in soils, surface waters, and bottom deposits, as well as higher gamma-ray background values above the Earth’s surface relative to the areas where the soils were formed on basic and intermediate ashes. This research resulted in the identification of two radioecological provinces in Kamchatka, viz., a Northern and a Southern province.     

Effect of Natural and Anthropogenic Factors on Soils,Soil Water,and Subsoil Water in Kola Peninsula

The concentrations of mobile compounds of S, Cu, and Ni are determined in podzol soils in the Murmansk region taken at different distances from Severonikel Copper–Nickel Plant and their variations are analyzed. The concentrations are found to have an effect on the distribution of these elements in lysimetric and subsoil waters.     

Inelastic seismic response of one-storey,asymmetric-plan systems: Effects of stiffness and strength distribution

The effects of plan-wise distribution of stiffness and strength-as determined by the number, location, orientation and yield deformations of resisting elements-on the inelastic response of one-storey systems are evaluated. In particular, various systems are investigated for wide ranges of parameters involved, with the objective of establishing how the response is influenced by: (i) the presence of resisting elements perpendicular to the direction of ground motion; (ii) the number of resisting elements along the direction of ground motion; (iii) the overstrength typical of code-designed buildings; (iv) the relative values of strength and stiffness eccentricities; and (v) whether the asymmetry of the system is due to eccentricity in stiffness or in mass. The results presented for a simple excitation make it possible to explain the inconsistencies in conclusions from various earlier investigations, and to evaluate their applicability to actual buildings.     

Elemental abundances in chondrules from unequilibrated chondrites: Evidence for chondrule origin by melting of pre-existing materials

Bulk abundances of Na, Mg, Al, Ca, Sc, V, Cr, Mn, Fe, Co, Ni, Zn, La, Sm, Eu, Yb, Lu, Ir, and Au were determined by neutron activation analysis of chondrules separated from unequilibrated H-, L-, and LL-chondrites (Tieschitz, Hallingeberg, Chainpur, Semarkona) and correlated with chondrule petrographic properties. Despite wellknown compositional differences among the whole-rock chondrites, the geometric mean compositions of their respective chondrule suites are nearly indistinguishable from each other for many elements. Relative to the condensible bulk solar system (approximated by the Cl chondrite Orgueil), chondrules are enriched in lithophile and depleted in siderophile elements in a pattern consistent with chondrule formation by melting of pre-existing materials, preceded or attended by silicate/metal fractionation. Relative to nonporphyritic chondrules, porphyritic chondrules are enriched in refractory and siderophile elements, suggesting that these two chondrule groups may have formed from different precursor materials.     

Rare-earth abundances in indian kimberlite

Abundances of some rare-earth elements (REE), together with Hf, Ta, Th, and Ba have been determined by neutron activation analyses in twelve kimberlite samples from Peninsular India. The kimberlites have fractionated REE patterns with enrichment of light rare earths; La/Yb ratio varies from 39 to 166. A systematic relationship exists between the total rare-earth abundances and the petrochemistry of the rocks. The rare-earth abundances observed in the kimberlites are consistent with their derivation by partial melting of a hydrous garnet peridotite mantle and subsequent fractional crystallization of the melt.     

Geochemical magma type discrimination: application to altered and metamorphosed basic igneous rocks

Five minor and trace elements, known to be chemically stable during alteration and metamorphism, have been combined in a set of binary diagrams that distinguish fresh tholeiites from alkali basalts. Of the five elements: Ti, P, Zr, Y, Nb, only P shows slight mobility during metamorphism, which is not sufficient to alter greatly the point distribution on the binary diagrams. Using these stable elements altered basaltic rocks: greenstones, spilites and amphibolites may be distinguished in the same way as fresh basalts, and their original magma may be identified as tholeiitic or alkaline basalt. All five elements are readily and rapidly determined, using XRF, thus this method may be applied as a rapid, easy way of discriminating the magma types of altered basaltic rocks. Using this method it can be demonstrated that alkali basalt magma was produced in minor quantities in the Precambrian.     

水面蒸发与散热系数公式研究(一)

根据自1976年以来全国水面蒸发与散热研究协作组在我国各典型地区的原体与室内实验资料和大量水文站历史资料,通过理论分析和统计检验,确定丁影响水面蒸发的诸因子及其非线性相互作用,引入了新的无量纲参数(w_e、Pv、Pe)和公式结构,用实测资料统计确定厂公式中的常系数,得到了用开敞湖面一般水文气象资料计算逐日蒸发和散热系数的公式。经全国各典型气候带内各季节湖泊(水库)和受热污染水体上原体观测和室内专题实验共1860组口平均资料检验,公式的精度高于现有其他公式。全文分两部分,这是第一部分,内容包括:影响水面蒸发的土要无量纲参数;感热输送和大气饱和度对蒸发影响的修正;水面蒸发计算公式的结构及其经验系数。     

Year to year variations in water balance components in the Volga Basin and their interaction

A method for the assessment of water balance components in a large water basin is discussed. The assessment is based on data on atmospheric precipitation and river runoff. The major components of annual water balance are determined for the Volga Basin for a period of 109 years (from 1892/1893 to 2000/2001). The main statistical characteristics of time series of water balance elements are estimated and their correlation is calculated.     

Shellfish from Todos os Santos Bay, Bahia, Brazil: treat or threat?

This study determined the concentrations of major and trace elements in shellfish (oysters, clams and mussels) and conducted an assessment of the health risks due to the consumption of contaminated seafood. Samples were collected at 34 sites along Todos os Santos Bay, Brazil. The elements were determined by ICP OES and Hg by Direct Mercury Analysis. Relatively high concentrations of trace elements (As, Zn, Se and Cu) were found in seafood tissues. Potential daily intake of As, Co, Se, Zn and Cu associated to shellfish consumption suggested relevant non-carcinogenic risk for all studied locations. Copper was the element that posed the greatest non-carcinogenic risk, while Pb posed the highest carcinogenic risk. Health risks for humans were greatest from the consumption of mussels. Contaminated shellfish offer the greatest risk for children, subsistence fishers and subsistence shellfish consumers.     

Fluorine,chlorine and lithium distribution in igneous rocks of lipari and vulcano (Aeolian Islands,Italy)

Fluorine and chlorine have been determined in samples of lavas and pyroclastic products from the islands of Lipari and Vulcano, which form the southernmost portion of the Aeolian arc, because their present distribution may provide additional information for a better understanding of the differentiation and eruptive mechanisms affecting these volcanoes. On the basis of previous data which did not reveal a significant presence of Cl- and F-bearing minerals, these two elements are expected to concentrate in the residual melt during differentiation, following a distribution pattern similar to that of lithium that is a typical residual constituent. The analytical results are in good agreement with the hypothesis which attributes a positive role to potassium in the solubility of volatiles in the melt phase, while silica would favour their escaping in a gaseous form. For rocks representing the last stages of differentiation a sharp increase in litium concentration is observed, and the relative loss of fluorine and chlorine is attributed to their releasing as constituents of fumarolic fumes. If the system is to a certain extent sealed, a « normal » passive enrichment for all the considered elements may occur.     

Strength capacity of unreinforced masonry cylindrical columns under seismic transverse forces

In this paper, the seismic resistance of unreinforced masonry (URM) cylindrical columns is investigated with an equivalent static analysis procedure. To this end, an existing numerical model developed for the stability analysis of masonry elements with rectangular cross-section is utilized and modified for the cylindrical columns. In the numerical model which takes into account the cracking of the sections and the second-order effects, the columns are divided ideally into sufficiently high number of elements, each having uniform curvature. The columns are modeled as prismatic cantilevers undergoing their own weights, eccentric vertical loads and distributed and concentrated static horizontal loads equivalent to the inertia actions. By considering two examples of columns, firstly a reference column and secondly a column from a real building, lateral seismic coefficient versus top drift level curves are obtained. On the basis of these curves, lateral load behavior of the columns is interpreted and maximum seismic load values which can be resisted by each column are determined. Implementing parametric analyses on the reference column, sensitivity of the seismic resistance to parameters such as column slenderness, magnitude and eccentricity of vertical top load, and the flexibility parameter is determined. The influence of some structural imperfections such as the deviation from vertical on the seismic resistance is also discussed in the paper.     

Three-dimensional hybrid modelling of soil-structure interaction

A three-dimensional hybrid model for the analysis of soil-structure interaction under dynamic conditions is developed which takes advantage of the desirable features of the finite element and substructure methods and which minimizes their undesirable features. The modelling is achieved by partitioning the total soil-structure system into a near-field and a far-field with a hemispherical interface. The near-field, which consists of the structure to be analysed and a finite region of soil around it, is modelled by finite elements. The semi-infinite far-field is modelled by distributed impedance functions at the interface which are determined by system identification methods. Numerical results indicate that the proposed model makes possible realistic and economical assessment of three-dimensional soil-structure interaction for both surface and embedded structures.     

Distorted Froude‐scaled flume analysis of large woody debris

This paper presents the results of a movable‐boundary, distorted, Froude‐scaled hydraulic model based on Abiaca Creek, a sand‐bedded channel in northern Mississippi. The model was used to examine the geomorphic and hydraulic impact of simplified large woody debris (LWD) elements. The theory of physical scale models is discussed and the method used to construct the LWD test channel is developed. The channel model had bed and banks moulded from 0·8 mm sand, and flow conditions were just below the threshold of motion so that any sediment transport and channel adjustment were the result of the debris element. Dimensions and positions of LWD elements were determined using a debris jam classification model. Elements were attached to a dynamometer to measure element drag forces, and channel adjustment was determined through detailed topographic surveys. The fluid drag force on the elements decreased asymptotically over time as the channel boundary eroded around the elements due to locally increased boundary shear stress. Total time for geomorphic adjustment computed for the prototype channel at the Q₂ discharge (discharge occurring once every two years on average) was as short as 45 hours. The size, depth and position of scour holes, bank erosion and bars created by flow acceleration past the elements were found to be related to element length and position within the channel cross‐section. Morphologies created by each debris element in the model channel were comparable with similar jams observed in the prototype channel. Published in 2001 John Wiley & Sons, Ltd.     

Sr isotopic fractionation in Allende chondrules: A reflection of solar nebular processes

True relative Sr isotopic compositions, determined by the double-spike technique, are reported for 8 olivine chondrules from Allende and a single chondrule from Richardton. The Richardton chondrule has an Sr composition identical with the whole meteorite, but the Allende chondrules are up to 1.4‰ per mass unit light-isotope enriched, closely similar to Ca-Al inclusions (CAI) from the same individual stone. The correspondence of the patterns for chondrules and CAI suggests that both groups of objects derived their fractionated Sr in similar ways. The lack of any detectable non-linear Sr isotopic anomaly in the objects suggests that their Sr compositions did not have some exotic or extrasolar origin, but were derived from normal solar system Sr by mass fractionation. The consistent light-Sr enrichment of Allende objects may be explained by several schemes, and all are heavily model-dependent. Most plausible to the author is that the CAI and chondrules derived their fractionated Sr from a region of the nebula made isotopically light by partial kinetic mass separation of elements in the vapour phase. Later, the solid objects may have moved to an isotopically more normal region, where the Allende matrix accreted.     

Trace element contaminations of roadside soils from two cultivated wetlands after abandonment in a typical plateau lakeshore, China

Total concentrations of As, Cd, Cu, Ni, Pb and Zn were determined in order to assess their changes in contamination levels in roadside soils of long-term abandoned tillage (LAT) belt and short-term abandoned tillage (SAT) belt from a plateau lakeshore of China. Results showed that the mean concentrations of these trace elements except for Cd and Pb were lower than background values. The contamination index values of these trace elements fluctuated and generally decreased with increasing distances from the road in both sampling belts except for Cu and Ni. Both LAT and SAT soils were facing Cd and Pb contamination. The integrated contamination level was more serious in LAT soils compared to SAT soils, with heavy contamination levels at the distances from 5 to 10 m in LAT soils. The effects of the studied rural road on both belts were clearly shown up to 250 m away from the road.     

Mechanism for open management of harmonizing water use strategies under stochastic conditions

The study is focused on the harmonization of water use and removal strategies employed by a management body of a water resource system (center) and water users, i.e., active elements, which can intentionally distort information about their potentialities and preferences. The harmonization mechanism is based on the open-management (fair-play) principle. The instruments of harmonization are prices for water use and removal. When the volumes of allocated water resources and the masses of removed chemicals are determined independently, the harmonization is perfect, while when the joint management of the amount and quality of water resources is used, the harmonization is approximate.