Search results for "Mercury"

Mercury and chlorinated hydrocarbons in the food chain of Lake Paijanne, Finland

1978

The sediments and various organisms in Lake Paijanne were examined for contaminants. The average mercury content of water plants was 9, of plankton 14, of sediment 114, of zoobenthic predators 83, of fish 332–1510 and of birds 240–13685 μg kg−1 (wet weight). The average PCB content of plants was 3, of plankton 21, of the zoobenthos 44, of fish 36-117 and of birds 219–13490 μg kg−1. The average ΔDDT content of plants was 0.5, of plankton 6, of the zoobenthos 14, of fish 7–42 and of birds 144-8262 μg kg−1. Regional differences in mercury content were most pronounced in sediment and fish. PCB concentration was highest near a town. ΔDDT was quite evenly distributed. Water plant species did not …

Advanced Stochastic Petri Net Modeling with the Mercury Scripting Language

2017

Formal models are widely used in performance and dependability studies of computational systems. Graphical modeling tools allow users to compose such models with ease, but they complicate the creation of models with a dynamic/complex structure, the hierarchical arrangement of different models, and the automatic execution of models with different parameter configurations. To overcome this problem, we created a scripting language for the Mercury tool that supports the combination of different modeling approaches (e.g., Stochastic Petri Nets and Reliability Block Diagrams) in a single project. In this paper, we focus on the extensions developed to improve the capabilities of Generalized Stocha…

Response of soil bacterial community structure to successive perturbations of different types and intensities

2008

SummaryIn soil, genetic structure modifications of indigenousbacterial community consecutively to a severe stress(mercury contamination) were delayed when thecommunity was pre-exposed to various minor per-turbations (heat, copper and atrazine). Such minorperturbations induced transitory community struc-ture modifications leading to an increase of commu-nity stability towards a severe mercury stress. Theseresults illustrated well the short-term pre-adaptationprocess for bacterial community hypothesizing thatcommunity submitted to perturbations become moreresistant to withstand another stress. Compared with other environmental matrices of the bio-sphere, soils are considered as the main reservo…

Chemistry of ?-hydridobis[pentacarbonylchromium(0)] species. Part III. Redox reactions with mercury(II) compounds and iodine

1981

[Cr2(CO)10(μ-H)]− undergoes ready hydride substitution on reaction with HgX2 (X = Cl, Br, I or SCN) or with iodine in acetone, yielding [Cr2(CO)10(μ-X)]− complex species which can be converted quantitatively into [Cr(CO)5X]− anions by reactions conducted in the presence of an excess of X−.

‘In situ’ preparation of nitrous acid solutions by photoreduction in a flow assembly for analysis of pharmaceuticals

2003

The solutions of nitrite ion, or nitrous acid, are frequently used as reagent in different analytical procedures and in pharmaceutical analysis. The low stability of the aqueous solutions of this reagent implies the tedious work of freshly prepared solutions every day and being kept in the refrigerator. In this paper, a photoreactor formed by a low pressure mercury lamp and nesting in a continuous-flow manifold is studied, tested, and proposed for the in situ reduction of nitrate solution into nitrite. The conversion into nitrite is reproducible and it has been successfully applied to determination of different drugs, mostly from the sulphonamide family, in an FIA assembly.

New data on the mercury antimony mineral shakhovite: Chemical composition, unit cell and crystal structure

1982

A new investigation of the mercury antimony mineral shakhovite yielded space groupIm witha=4.871(1),b=15.098(3),c=5,433(1) A and β=98.86(2)°. The determination of the crystal structure gave a cell content of Hg8Sb2O12. Since the presence of Hg2-groups indicates that shakhovite is a pure Hg(1) compound and the infrared spectrum shows an absorption band at 3440 cm−1 which is due to the OH-stretching frequency, it is assumed that there are six oxygen atoms and six OH-groups in the unit cell. Thus the chemical formula of shakhovite reads Hg4Sb(OH)3O3 with two formula units per unit cell. The Hg−Hg distance in the Hg2-group is 2.543 A, each mercury atom has a close oxygen neighbour at 2.160 and …

Small Azaparacyclophanes as Potential Selective Scavengers of Mercury. Crystal Structure of the Complex Hg2(L1)Cl4 (L1 = 16,17,19,20-Tetramethyl-2,6,…

1996

Organomercury(II) and organothallium(III) complexes with Cis-1,2-dicyanoethylenedithiolate ion

1977

Sequestering ability of some chelating agents towards methylmercury(II).

2013

A study on the interactions between CH3Hg+ and some S, N and O donor ligands (2-mercaptopropanoic acid (thiolactic acid (H2 TLA)), 3-mercaptopropanoic acid (H2 MPA), 2-mercaptosuccinic acid (thiomalic acid (H3 TMA)), d,l-penicillamine (H2 PSH), l-cysteine (H2 CYS), glutathione (H3 GSH), N,N′-bis(3-aminopropyl)-1-4-diaminobutane (spermine (SPER)), 1,2,3,4,5,6-benzenehexacarboxylic acid (mellitic acid (H6 MLT)) and ethylenediaminetetraacetic acid (H4 EDTA)) is reported. The speciation models in aqueous solution and the possible structures of the complexes formed are discussed on the basis of potentiometric, calorimetric, UV spectrophotometric and electrospray mass spectrometric results. For t…

Liquid intrusion and alternative methods for the characterization of macroporous materials (IUPAC Technical Report)

2011

This document deals with the characterization of porous materials having pore widths in the macropore range of 50 nm to 500 μm. In recent years, the development of advanced adsorbents and catalysts (e.g., monoliths having hierarchical pore networks) has brought about a renewed interest in macropore structures. Mercury intrusion–extrusion porosimetry is a well-established method, which is at present the most widely used for determining the macropore size distribution. However, because of the reservations raised by the use of mercury, it is now evident that the principles involved in the application of mercury porosimetry require reappraisal and that alternative methods are worth being listed…