9 research outputs found

    Mathematical model of integrated thermal apparatus

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    Mathematical model for the integrated thermal apparatus was developed. It consists of program modules from which individualfurnace model can be generated. For the model generation elementary balance method was used. Generation of the individual modelincludes model formulation and parameters determination. Model formulation is based on first principles, heuristics and empirical results.Parameters determination is generally based on priory information, but it has to take into account specific conditions. The developed modelwas adapted for real time applications. For quantitative application developed model has to be calibrated. For the calibration theoperational furnace can be used. For model calibration of not existing furnace the priory knowledge and physical model can be used.Presented model was calibrated on experimental furnace. The results were gained by simulations

    Long-Term Changes of Softwood Floodplain Forests—Did the Disappearance of Wet Vegetation Accelerate the Invasion Process?

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    Objectives: We followed the long-term changes of softwood floodplain forests strongly altered by water regime changes and examine the behaviour of neophytes in this environment. Here we ask: (1) How did the composition of neophyte and native species change? (2) How did the presence of species that prefer wetter conditions change? (3) What traditionally distinguished type of softwood floodplain forests (a wetter one or a more mesophilous one) do neophytes prefer? (4) What environmental factors affect the native species richness and the occurrence and cover of neophytes? Materials and Methods: Historical and recent phytosociological relevés of the association Salicetum albae of the Slovak part of the inland delta of the Danube River were used (177 plots together). For each plot, the number and cover of neophytes and number of native species were measured, and the Shannon-Wiener diversity index, the stand structure (cover of tree, shrub and herb layer) and the mean of Ellenberg indicator values were calculated and compared among time periods. Temporal trends of the soil moisture characterized by indicator values calculated for each plot were determined using a Linear Model. The synoptic table of traditional vegetation types was done to show preferences of neophytes for particular softwood forest types. The effect of site conditions on native species richness and occurrence of neophytes was determined using the Generalized Linear Model. Results: The relative number and cover of neophyte species increased and the absolute number of native species decreased over time; the vegetation of the area has changed from variable hygrophilous and mesophilous to homogenised mesophilous; most non-native species prefer the mesophilous vegetation of the floodplain forests; the wetter parts of the floodplain more successfully resisted invasions. Conclusions: The vegetation of the researched area has considerably changed over time to become less diverse and less hygrophilous, and has more invasive species. To preserve floodplain forests, natural hydrological and connectivity patterns should be adequately protected

    Changes in the Agroclimatic Areas of Slovakia in 1961–2020

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    The World Meteorological Organisation predicts an increase in average annual temperature. As a result of climate change in Slovakia, one can expect changes in the distribution of precipitation and moisture availability, changes in the temperature availability of crop production, changes in wintering conditions, and many others. The aim of this work was the analysis of agroclimatic indicators for the period 1961–1990 and 1991–2020. The results showed an increase in the sums of temperatures in the growing season. Also, the increase in temperature resulted in a change in the zones of the agroclimatic indicator of moisture and the agroclimatic indicator of wintering. The zones have been shifting to higher altitudes throughout Slovakia

    Changes in the Agroclimatic Areas of Slovakia in 1961–2020

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    The World Meteorological Organisation predicts an increase in average annual temperature. As a result of climate change in Slovakia, one can expect changes in the distribution of precipitation and moisture availability, changes in the temperature availability of crop production, changes in wintering conditions, and many others. The aim of this work was the analysis of agroclimatic indicators for the period 1961-1990 and 1991-2020. The results showed an increase in the sums of temperatures in the growing season. Also, the increase in temperature resulted in a change in the zones of the agroclimatic indicator of moisture and the agroclimatic indicator of wintering. The zones have been shifting to higher altitudes throughout Slovakia

    Analysis of Sub-Daily Precipitation for the PannEx Region

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    The PannEx is a GEWEX-initiated, community driven research network in the Pannonian Basin. One of the main scientific issues to address in PannEx is the investigation of precipitation extremes. Meteorological Services in the PannEx area collected the hourly precipitation data and commonly used a computer program, which was developed in the INTENSE project, to produce a set of global hydro-climatic indices. Calculations are carried out on data aggregated 1-, 3- and 6-h intervals. Selected indices are analyzed in this paper to assess the general climatology of the short-term precipitation in the Pannonian basin. The following indices are illustrated on maps and graphs: the annual mean and maxima of 1-h, 3-h and 6-h sums, the count of 3-hr periods greater than 20 mm thresholds, the maximum length of wet hours, the timing of wettest hour and the 1-h precipitation intensity. The seasonal trends of the 1-h precipitation intensity were tested from 1998 to 2019. Analysis of sub-daily precipitation has been limited by the availability of data on a global or a regional scale. The international effort made in this work through collaboration in the PannEx initiative contributes to enlarging the data availability for regional and global analysis of sub-daily precipitation extremes
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