The energy utilization of the alternative fuels is one of the main topics for future developments of recoverable sources in the European Union and in the Czech Republic. The aim of research is combustion tests in the fluidized-bed boiler Foster Wheeler located at Štětí. The experiments are carried out for Czech brown coal, wood, sewage sludge and wastes including analyses and recommendations for optimal thermal utilization and minimizing harmful emissions. The second step is thermal analyses of coal, alternative fuel- wood pellets and sewage sludge from treatment plant. From the results of experiments and thermal modeling it is clear that 15 % of alternative fuels can be used in the large fluidized-bed boilers located in the Czech Republic., Pavel Kolat, Bohumir Čech, Dagmar Juchelková, Helena Raclavská and Juraj Leško., and Obsahuje bibliografii
Review article presents utilisation of coal in industry, coal in power generation, gas production, Czech energy policy and outlook and application of clean coal technology in the Czech power stations. The further exploitation and utilisation of Czech coal resources requires the implementation of development programme aimed at the application of the new, economically effective technologies, of coal mining, utilisation, gasification. Emissions of GHG in CR., Václav Roubíček, Pavel Kolat and Jaroslav Buchtele., and Obsahuje bibliografii
Partitioning of exogenously supplied U-14C-saccharose into primary metabolic pool as sugars, amino acids, and organic acids was analyzed and simultaneous utilization for production of alkaloid by leaf, stem, and root in twigs and rooted plants of Catharanthus roseus grown in hydroponic culture medium was determined. Twigs revealed comparable distribution of total 14C label in leaf and stem. Stems contained significantly higher 14C label in sugar fraction and in alkaloids [47 kBq kg-1(DM)] than leaf. In rooted plants, label in 14C in metabolic fractions in root such as ethanol-soluble, ethanol-insoluble, and chloroform-soluble fractions and in components such as sugars, amino acids, and organic acids were significantly higher than in stems and leaves. This was related with significantly higher content of 14C in alkaloids in stems and leaves. 14C contents in sugars, amino acids, and organic acids increased from leaf to stem and roots. Roots are the major accumulators of metabolites accompanied by higher biosynthetic utilization for alkaloid accumulation. and N. K. Srivastava, A. K. Srivastava.
Heat stress is a major production constraint of sunflower worldwide. Therefore, various populations (parental, F1, F2, F3, and plant progenies) of sunflower were screened for leaf gas-exchange traits with the objectives to formulate selection criteria of heat resistance and development of heat-resistant lines. Initial screening and F2 seeds exposed to heat stress (45°C) resulted in the development of an adapted F2 population that showed leaf gas-exchange and morphological traits better than the unadapted population. Correlation coefficients of traits were partitioned into direct and indirect effects via a path analysis technique to determine the cause of their relationship with a basic parameter such as a reproductive head mass (HM). Path analysis showed a positive direct effect of leaf temperature (Tleaf) (0.32) on HM and also an indirect effect (0.77) of the transpiration rate (E) on HM. Moreover, Tleaf showed high heritability estimates. Tleaf was used to select superior plants within the F2 population. This selection brought about an improvement in the net photosynthetic rate (PN) and E as it was indicated from progeny performance and realized heritability. Progenies selected on the basis of Tleaf also showed an increase in achene yield and heat resistance over unselected F3 progenies and a commercial hybrid. and T. Kalyar ... [et al.].
Partitioning of current photosynthates towards primary metabolites and its simultaneous incorporation in leaf alkaloids was investigated in developing leaves of medicinally important Catharanthus roseus. Of the total 14CO2 assimilated, the leaves at positions 1-6 fixed 8, 22, 25, 19, 13, and 8 %, respectively, and stem 3 %. Leaf fresh mass, chlorophyll content, and CO2 exchange rate increased up to the third leaf. The total alkaloid content was highest in young actively growing leaves, which declined with age. Total 14C fixed and its content in ethanol soluble fraction increased up to the third leaf and then declined. The 14C content in primary metabolites such as sugars and organic acids was also highest in the 3rd leaf. The utilization of 14C assimilates into alkaloids was maximum in youngest leaf which declined with leaf age. Hence the capacity to synthesize alkaloids was highest in young growing leaves and metabolites from photosynthetic pathway were most efficiently utilized and incorporated into alkaloid biosynthetic pathway by young growing leaves. and N. K. Srivastava ... [et al.].