Turbidity and mass concentration of suspended matter in lake water: A comparison of two calibration methods

Turbidity measurements by foreward scattering nephelometer have been regularly conducted on the north basin of Lake Lugano (Switzerland/Italy) since September 1992. In order to determine mass concentrations from these data, both, in-situ and laboratory calibration experiments have been performed in November and December 1992 on suspended matter of the hypolimnion. Results show:

1. Mass concentration/turbidity ratios are different in the two turbidity zones examined due to variation in the optical signature of the suspended matter.
2. Laboratory calibrations using suspended matter originating from the water depths of interest give representative results provided that physical and chemical alterations occuring during the particle transfer process remain negligible.

     

Normal form,Lie-Poisson structure and reduction for the Henon-Heiles system

The reduced Henon-Heiles system is investigated as a Hamiltonian dynamical system obtained by applying the normalization of the HamiltonianH=1/2(p ₁ ² +p ₂ ² +q ₁ ² +q ₂ ² )+1/3q ₁ ³ –q ₁ q ₂ ² to fourth-degree terms. The related equations of motion are bi-Hamiltonian and possess the Lie-Poisson structure. Each Lie-Poisson structure possesses an associated Casimir function. When reduced to level sets of these functions, the equations of motion take various symplectic forms. The various reductions give different coordinate representations of the solutions. These coordinate representations are used to seek the simplest representation of the solutions.     

Tag retention and survival of fish tagged in controlled pond experiments

Fish survival, tag retention and tag loss were evaluated in pond experiments and described by linear regression equations. Tagging of fish had no significant influence on their survival. However, loss of tags caused strong differences between actual fish survival and the survival rate e^–z estimated on recovered tags. Mathematical functions were derived to correct tag loss. Values of those functions depend upon the type of tag and time after tagging. The B-type of tagging, which approximated the Swedish Carlin method, appeared to be most effective. The rate of tag loss was independent of the fish species (common carp, tench) used in the experiments.     

First-order theory of weakly eccentric orbital motion

Starting from the analytical theory of perturbed circular motions presented in Celestial Mechanics (Bois, 1994), this paper presents an extended resolution valid also for small eccentricity orbits. The solution is of the first order of a small parameter characterizing the magnitude of disturbing forces. The solution has the form of Fourier series with the coefficients given by iterative formation laws. The solution is free from singularities due to small eccentricity or inclination. As an example of numerical application the equatorial artificial satellite orbits are analyzed. For some high satellite orbits with small eccentricity the difference between the numerical integration and the analytical model does not exceed few centimeters per one revolution.On leave from Astronomical Observatory of A. Mickiewicz University, Soneczna 36, PL60-286 Pozna, Poland.     

On the energy gap for Fe-poor oxide and silicate minerals

A relationship between the energy gap (E _G) and the density (ρ) over mean atomic weight (〈A〉) ratio for Fe-poor oxide and silicate minerals is derived from simple properties of their free atom-components. Theoretical considerations are based on the Lorentz electron theory of solids. The eigenfrequency ν ₀ of elementary electron oscillators, in energy units h ν ₀, is identified with the energy gap of a solid. The numerical relation is of the form $$(\langle U_0 \rangle ^2 - E_G^2 )\frac{{\langle A\rangle }}{\rho } = \frac{4}{3}\pi \hbar ^2 \frac{{e^2 }}{m}N = 276.79 eV^2 cm^3 /mol$$ where 〈U ₀〉 is the average first ionization potential (per free atom), ? is crossed Planck's constant, e is the electron charge, m is the electron rest mass, and N is Avogadro's number. For several geophysically interesting oxide and silicate minerals which are in general composed of four different elements (O, Si, Mg and Al), we obtain from laboratory data that the mean value of $$\left\langle {[\langle U_0 \rangle ^2 - (E_G^{lab} )^2 ]\frac{{\langle A\rangle }}{\rho }} \right\rangle \approx 248.2 \pm 20.9eV^2 cm^3 /mol.$$ .     

Effects of rainy season on mobilization of contaminants from tsunami deposits left in a coastal zone of Thailand by the 26 December 2004 tsunami

Study on contamination of tsunami sediments deposited on 26 December 2004 conducted shortly after the tsunami in coastal zone of Thailand revealed elevated contents of salts in water-soluble and some heavy metals and arsenic in bioavailable fractions (Szczuciński et al. in Env Geol 49:321–331, 2005). Few months later rainy season started and effected in total rainfall of over 3,300 mm. This paper presents results of survey repeated 1 year after the tsunami. To assess the effects of rainy season on mobilization of previously determined potential contaminants, the same locations were sampled again and analysed with the same methods. The tsunami deposit layer was well preserved but in many locations the sediments were coarser than just after tsunami due to washing out of finer fractions. The water-soluble salts contents were strongly reduced after the rainy season. However, the concentrations of acid leachable heavy metals and metalloids were still elevated in comparison to reference sample from an area not impacted by tsunami. It is possible that the metals and metalloids are successively moved to more bioavailable fraction from forms which were more resistant to mobilization.     

Atmospheric deposition and isotope biogeochemistry of zinc in ombrotrophic peat

Zinc isotope ratios were measured in the top sections of dated ombrotrophic peat cores in Finland to investigate their potential as proxies for atmospheric sources and to constrain post depositional processes affecting the geochemical record. The peat deposits were located in Hietajärvi, a background site well away from any point pollution source and representing ‘background’ conditions, in Outokumpu, next to a mining site, and in Harjavalta, next to a smelter. Measured total concentrations, calculated excess concentrations and mass balance considerations suggest that zinc is subjected to important biogeochemical cycling within the peat. Significant isotopic variability was found in all three peat bogs, with heavier zinc in the deeper and lighter zinc in the upper sections. Isotope ratios and concentrations correlated in the two peats located next to dominant point sources, i.e. the smelting and mining site, suggesting that zinc isotopes trace pollution sources. Concentration and isotope peaks were offset from the period of mining and smelting activity, supporting migration of zinc down the profile. The δ⁶⁶Zn_JMC (where δ⁶⁶Zn = [(⁶⁶Zn/⁶⁴Zn)_sample/(⁶⁶Zn/⁶⁴Zn)_JMC-standard − 1] × 10³) of the top section sample at the remote Hietajärvi site was 0.9‰ and we suggest this represents the regional background isotope signature of atmospheric zinc. The deeper sections of the peat cores show isotopically heavier zinc than any potential atmospheric source, indicating that post depositional processes affected the isotopic records. The large variations encountered (up to 1.05‰ for δ⁶⁶Zn) and Rayleigh modelling imply that multiple fractionation of zinc during diagenetic alterations occurs and nutrient recycling alone cannot explain the fractionation pattern.We propose that zinc isotopes are amenable to identify different atmospheric zinc sources, including zinc derived from anthropogenic activities such as mining and smelting, but multiple biogeochemical processes seriously affect the record and they need to be evaluated and assessed carefully if zinc isotopes are used in terrestrial paleorecords.     

Archaeological objects in loesses recognized by GPR research at the site Karmanowice,Poland

The aim of the research was to examine subsurface soil layers with the use of the Ground Penetrating Radar (GPR) method. Neolithic archaeological post in Karmanowice was examined. On the basis of earlier geophysical researches and archaeological premises, eight measurement profiles had been chosen. Ground Penetrating Radar system with antenna of 500 MHz frequency was applied. The measurements were made with 30 and 60 ns time windows. The results were shown as the GPR sections. The analysis of the obtained results allowed us to outline anomalies connected with the appearance of archaeological objects in subsurface soil layers. The border between the anthropogenically changed upper layer and undisturbed loess was established, and the sections of slope wash layers were designated. Anomalies were confirmed by digging and test drillings. Additionally, 2D resistivity imaging method was used for verification of specific anthropogenic anomalies.