Strong dependence between phytoplankton and water chemistry in a large temperate lake: spatial and temporal perspective

Hydrobiologia ◽  
2013 ◽  
Vol 731 (1) ◽  
pp. 139-150 ◽  
Author(s):  
A. Heini ◽  
I. Puustinen ◽  
M. Tikka ◽  
A. Jokiniemi ◽  
M. Leppäranta ◽  
...  
Author(s):  
Daniel Callahan ◽  
G. Thomas

Oxygen impurities may significantly influence the properties of nitride ceramics with a strong dependence on the microstructural distribution of the impurity. For example, amorphous oxygen-rich grain boundary phases are well-known to cause high-temperature mechanical strength degradation in silicon nitride whereas solutionized oxygen is known to decrease the thermal conductivity of aluminum nitride. Microanalytical characterization of these impurities by spectral methods in the AEM is complicated by reactions which form oxygen-rich surface phases not representative of the bulk material. Furthermore, the impurity concentrations found in higher quality ceramics may be too low to measure by EDS or PEELS. Consequently an alternate method for the characterization of impurities in these ceramics has been investigated.Convergent beam electron diffraction (CBED) is a promising technique for the study of impurity distributions in aluminum nitride ceramics. Oxygen is known to enter into stoichiometric solutions with AIN with a consequent decrease in lattice parameter.


2004 ◽  
pp. 51-69 ◽  
Author(s):  
E. Sharipova ◽  
I. Tcherkashin

Federal tax revenues from the main sectors of the Russian economy after the 1998 crisis are examined in the article. Authors present the structure of revenues from these sectors by main taxes for 1999-2003 and prospects for 2004. Emphasis is given to an increasing dependence of budget on revenues from oil and gas industries. The share of proceeds from these sectors has reached 1/3 of total federal revenues. To explain this fact world oil prices dynamics and changes in tax legislation in Russia are considered. Empirical results show strong dependence of budget revenues on oil prices. The analysis of changes in tax legislation in oil and gas industry shows that the government has managed to redistribute resource rent in favor of the state.


2012 ◽  
pp. 80-97
Author(s):  
B. Kheifets

The paper discusses the debt component of the current global crisis, which becomes stronger in 2011—2012. The Russian economy is analyzed in terms of its debt stability: a thorough analysis shows that it is not quite adequate. This paper presents the main problems that could be exacerbated by the global debt crisis (strong dependence of the budget on the volatility of oil prices, deterioration of conditions for external borrowing and overheat of the domestic debt market, too high public pension liabilities, substantial corporate debt and high level of state paternalism in regard to big business). Some measures to address Russian debt policy problems are proposed.


2008 ◽  
Vol 37 (1) ◽  
Author(s):  
Tomasz Kakareko ◽  
Paweł Napiórkowski ◽  
Jacek Kozłowski

Diet composition and prey selection of vendaceLake Ostrowite is a mesotrophic lake in Northern Poland 280.7 ha in area and 43 m deep at its deepest point. To study vendace (


Author(s):  
Z. I. Khazheeva ◽  
S. S. Sanzhanova

The Dzhida ore field in the Zakamensk district of Buryatia features high concentration of mineralization within a small area. The Dzhida deposit is composed of complex ore. The ore field contains commercial-value primary deposits: Pervomai stockwork of molybdenum, Kholtoson tungsten lode and Inkur stockwork of tungsten. The Modonkul river catchment basin lies inside the Dzhida ore field. A real threat to the town of Zakamensk is created by manmade sand-bulk (old) tailings and slurry dump. By now, the concentrated flow of natural and man-made sand enters the low terrace and floodplain of the Modonkul river in the form of a talus train. This study is focused on the influence of the mine drainage effluent and the Inkur tributary on the water chemistry in the Modonkul river. 80 water samples were taken from the surface layer 0-0.5 m thick at five stations. Physicochemical indices of water were measured at the water sampling points, and the water chemistry was analyzed in a laboratory. In the background conditions, cations and anions in the Modonkul water chemistry range in decreasing order as follows: Са2+ > Mg2+ > Na++К+ и HCO - > SO 2- > Cl-. In the zone of mixture of natural and mine process water, the chemistry changes: from hydrocarbonate to sulfate (anion), from calcium-magnesium to sodium-calcium (cation). Downstream the natural chemistry changes to the hydrocabonate-sulfate composition, with prevailing content of calcium in cations. Iron content of water lowers 3-4 times after influx of mine effluents, while the contents of Mn, Zn, Co and Cd grow and then decrease downstream.


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