Combustion of lignite with limestone, co-combustion of lignite with limestone and wood, and combustion of wood were performed in a circulating fluidised bed in 7 different combustion regimes. The in organic matter composition and properties of all input and output materials were characterized. For each com bustion regime the material streams and the boiler outputs were calculated. The total inorganic mass and the mass of selected trace elements in fuels (Cl, Zn, As, Se, Hg, and Pb) were based on the output of a 1 GW circulating fluidised-bed boiler; additionally, the concen trations of volatile elements (As, Se, Hg) in fly ash (FA) were evaluated in relation to the mass of FA. Element (Cl, Zn, As, Se, Hg, and Pb) enrichment in FA compared with BA was related to the ratio R between the co mbusted mass of organic wood wastes and total combusted fuel. Additionally, the unburned carbon in bottom ash (BA) and fly ash (FA) was determined, and sel ected elements were studied in unburned materials separated from BA. The results show that combustion of wood and/or co-combustion of lignite with wood waste brings about significant environmental benefits., Zdeněk Klika, Lucie Bartoňová and Jana Serenčíšová., and Obsahuje bibliografické odkazy
Long-term changes in the frequency of floods on the Vltava river in Prague and the Elbe river in Děčín in relation to atmospheric circulation and heavy precipitation.
a1_In cooperation with AIUB (Astronomical Institute University of Berne), GOP (Geodetic Observatory Pecný) and IGN (Institut Géographique National), DORIS data analysis capabilities were implemented into the development version 5.0 of the Bernese GPS Software. The DORIS observables are reformulated that they are similar to GNSS carrier phase observations as much as possible allowing the use of the same observation models and algorithms as for GNSS carrier phase data analysis with only minor modifications. Evolution of DORIS data analysis using Bernese GPS Software is presented from the pilot campaign (September 2004) to the automatic processing of multi-year data time-series. The station and pole coordinates were estimated within the free-network approach and the long time-series of weekly estimated parameters are presented (1993.0- 2009.0) and analyzed. The RMS of the estimated polar coordinates significantly decreased after 2002, when the second generation of DORIS satellites was launched. A significant improvement has been achieved by processing the data from the new satellites (SPOT-5 and Envisat) launched in 2002. The RMS in 2003-2009.0 shows the decreasing trend and reached values close to 0.4 mas in both coordinates (2007-2008). Behavior of the terrestrial reference frame scale was quite stable with a few exceptions. Analysis of the major scale shift at the end of 2004 revealed the SPOT-5 and Envisat satellites as the source of the problem. On the other hand, the termination of the TOPEX/Poseidon DORIS data processing at the end of 2004 did not influence significantly the overall scale level. Another goal of the paper is a detail analysis of relations between the value of the observation residuals and the length of the observation time-interval. A simple empirical model considering the observation noise as a sum of the constant and time-dependent terms is applied and discussed., a2_A significant DORIS-GNSS ZTD bias as well as station height bias have been detected in the case of the SPOT-5 data for South America stations Santiago, Cachoiera Paulista, and Arequipa. These stations are located in the area of the South Atlantic Anomaly (SAA)., Petr Štěpánek, Vratislav Filler, Urs Hugentobler and Jan Douša., and Obsahuje bibliografii
Microseismic monitoring has become a standard technique to map the development of hydraulic fracturing. This study is a case study of a downhole monitoring of the hydraulic fracturing in a lateral well in Northern Poland. The downhole monitoring array detected a large number of microseismic events indicating successful development of a hydraulic fracture. We show evidence that some stages interacted with the pre-existing natural fault system also mapped from surface active seismic imaging. The mapped hydraulic fracture shows a slight asymme try of the developed hydraulic fractures. We show that the observed microseismicity is cons istent with microseismicity usually observed in the North American shale gas stimulations., Eryk Święch, Paweł Wandycz, Leo Eisner, Andrzej Pasternacki and Tomasz Maćkowski., and Obsahuje bibliografické odkazy
The long water-tube tiltmeter observations of the plumb line variations were begun about four years ago. Since 2001, twice, the instrument registered strong plumb line variations associated with earthquake. Earthquake in September 2003 made opportunity for verification of hydrodynamic system of tiltmeter. We obtained in observations large number of cycle-slip effects, which made impossible correct interpretation of data during main phase of phenomenon. Results of tests of dumping system of water waving helped us to introduce some improvements in hydrodynamic system of instrument. Catastrophic earthquake with magnitude 9.1 which took place in the area of Indian Ocean on 26th December 2004 generated phenomenon of the Earth free oscillations associated with anomalous plumb line variations of the order of single milliseconds of arc (mas). The effects of surface waves passing associated with Earth free oscillations were registered by the tiltmeter as series of anomalous plumb line variations. Surface waves produced several milliseconds of arc amplitude of plumb line variations. Results of observations showed that low-pass filters considerably reduce contribution of short-period effects and effectively protect hydrodynamic system of instrument against resonance. Nevertheless during first two hours of phenomenon cycle-slip effects occurred several times. Plot of plumb line variations in space from 26th December 2004 showed us large complication of tilt signals as well as dominated role of tidal signal. Spectral analysis of the time series of the plumb line variations obtained with help of the long water-tube tiltmeter on 26 December 2004 appeared existing fundamental modes (n = 0) in the Earth free oscillations didn’t exceed 0.2 mas., Marek Kaczorowski., and Obsahuje bibliografii
The orientation of the Earth in space is measured by space geodetic techniques. Each technique has its weaknesses so the best way how to get a representative solution of Earth orientation parameters is to combine all of them together using some appropriate method. There are basically two approaches, the rigorous and non-rigorous one. The method used in this paper belongs to the second category. Since 1999, when the authors Kostelecký and Pešek put basis of the combination method, the method has been modified and improved. The particular improvements are described hereafter and recent results are presented. These results of collocation station velocities are compared with the velocities published by ITRF 2005 and NUVEL-1A. The mean values of differences are 2.7 mm/y and 5.9 mm/y, respectively., Vojtěch Štefka, Ivan Pešek, Jan Vondrák and Jan Kostelecký., and Obsahuje bibliografii
Recently we derived a new star catalog EOC-4 that contains not only the mean positions and linear proper motions, but also periodic changes, due to orbital motions, for double and multiple star systems. The catalog contains 4418 stars that were observed in programs monitoring Earth orientation by optical astrometry during the 20th century. 599 stars of the catalog have significant periodic components. This catalog is now used, as a basic celestial frame, to obtain the Earth orientation parameters from optical astrometric observations of latitude/universal time/altitude in the interval 1899.7-1992.0. Polar motion is determined in 5-day steps for the whole interval studied, Universal time covers the interval 1956.0-1992.0 (i.e., after the invention of atomic clocks) also in 5-day steps, and celestial pole offsets (with respect to recent IAU2000 and IAU2006 models of nutation and precession) are modeled by second-order polynomials of time. In addition to these, a combination of Love and Shida numbers for each observing site is computed., Jan Vondrák, Cyril Ron and Vojtěch Štefka., and Obsahuje bibliografii