National Repository of Grey Literature 184 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Methodology for rapid, comprehensive, independent decision-making on the need, effectiveness and interaction of adaptation measures in river basins under climate change
Fischer, Milan ; Zeman, Evžen ; Vizina, A. ; Hanel, M. ; Bernsteinová, Jana ; Tachecí, Pavel ; Štěpánek, Petr ; Pavlík, P. ; Máca, P. ; Ghisi, Tomáš ; Rapantová, N. ; Bláhová, Monika ; Janál, P. ; Trnka, Miroslav
The aim of the methodology is to present methods for quantifying the impacts of projected climate change on the water balance when applying adaptation measures in the Czech Republic for the next few decades. Adaptation measures should contribute to the sustainability of the water balance in all major user segments of water use and management in the basin. The main principle is the use of hydrological models to transform climate change scenarios into time series of hydrological conditions and to quantify the overall water balance of the basin using different types of adaptation measures and their implementation over time. Special emphasis is placed on the evaluation of combinations of adaptation measures that cannot be analysed by simplified methods. The methodology is designed to search for the optimal combination of adaptation measures in the assessed catchment. The proposed approach eliminates the shortcomings of effectiveness assessment from the perspective of the exclusive user of the water resource, as the evaluation of the effectiveness of adaptation measures is carried out in the form of a multi-criteria analysis of the evaluation of the outputs of the simulation model for predicting the water balance in the whole basin. This methodology can be used to assess different adaptation measures in all basic segments of water users: agriculture, forestry, energy, water management and others.
Methodology for determining the main disturbances in the water management balance and optimizing adaptation measures in the conditions climate change
Fischer, Milan ; Zeman, Evžen ; Vizina, A. ; Hanel, M. ; Bernsteinová, Jana ; Tachecí, Pavel ; Štěpánek, Petr ; Pavlík, P. ; Máca, P. ; Ghisi, Tomáš ; Rapantová, N. ; Bláhová, Monika ; Janál, P. ; Trnka, Miroslav
Ongoing climate change is causing a global increase in air temperature. While this is leading to an acceleration of the global hydrological cycle, and therefore a global increase in precipitation, the spatiotemporal variability in precipitation is much more complicated. While temperature in the Czech Republic shows a consistently increasing trend similar to that of surrounding countries and the planet as a whole, precipitation can be simplified that long-term averages of annual totals remain and are likely to remain very similar in the coming decades. Rising air temperatures inherently bring increased evaporative demand of the atmosphere and, for the same precipitation, a lower ratio of precipitation to evaporation, i.e. the climatic water balance shows a negative trend.
Stochastic Weather Generators and Regional Climate Models: Rivals or Allies?
Dubrovský, Martin ; Štěpánek, Petr ; Meitner, Jan ; Zahradníček, Pavel
The paper demonstrates 'collaboration' between the stochastic weather generator SPAGETTA (WG) and Regional Climate Models (RCM) in analysing impacts of Climate Change (CC). In the first part of the paper, the generator is compared with the ensemble of 19 RCMs in terms of their ability to reproduce 11 spatial temperature and precipitation indices in eight European regions: the indices are based on registering days and spells exhibiting spatially significant occurrence of dry, wet, hot or cold weather, or possible combination of dryor-wet and hot-or-cold conditions. The obtained results indicate that both methodologies provide weather series of comparable quality. In the second part of the paper (which was done only for the Central Europe region), the WG parameters are modified using the RCM-based CC scenarios and the synthetic weather series representing the future climate are produced. This experiment is based on a set of CC scenarios, which consist of changes in selected combinations of following characteristics: (1) mean temperature, (2) temperature variability, (3) daily average precipitation (considering only wet days), (4) probability of wet day occurrence, (5) spatial lag-0 and lag-1day correlations of temperature and precipitation series. The synthetic series generated for each version of the CC scenario are analysed in terms the above mentioned spatial validation indices, the stress was put on effect of each of the five component of the CC scenario on individual validation indices. The results of the experiment indicate that the changes in temperature means is the main contributor to the changes in the validation obviously, except for the purely precipitation-based indices. Positive changes in the lag-0 and lag-1day correlations of both temperature and precipitation are the second most significant contributor to the changes in the validation indices.
Use of the Agrorisk.cz portal – an early warning system against the negative effects of weather on agriculture
Žalud, Zdeněk ; Svobodová, Eva ; Klem, Karel ; Hlavinka, Petr ; Semerádová, Daniela ; Zahradníček, Pavel ; Štěpánek, Petr ; Bláhová, Monika ; Kudláčková, Lucie ; Balek, Jan
The early warning system against negative weather effects offers a daily updated description of abiotic and selected biotic risks threatening field production at the cadastral level. It includes their 9-day forecast. The methodology is primarily intended for agronomists,plant doctors and agricultural managers, as well as scientists, agricultural consultants and representatives of public administration.
Comparison of the efficiency of different sets of lines for post-harvest treatment of cereals with regard to their energy intensity
ŠTĚPÁNEK, Petr
The current energy crisis is having a significant impact on many industries around the world, and it is also significant in the Czech Republic. Apart from agriculture, the food industry, which is directly linked to agriculture, is also affected. The aim of this theses is to compare the efficiency and energy consumption of the post-harvest treatment process of spring barely, Bente variety. To compare the harvested and subsequently clean and properly postharvest treated barley grain, two different post-harvest lines equipped with a screen or aspiration grain cleaner were used. The grain was sampled in both cases in August 2022 and assessed for moisture, bulk density, HTZ, impurities and impurities. For the post-harvest lines, the energy requirements of grain cleaning was then calculated. The screen grain cleaner is more suitable for the removal of hea-vier components of the grain mass such as fractions. The aspiration grain cleaner is more suitable for the removal of lighter admixtures and impurities and its use is less energy intensive.
Bond between FRP reinforcement and concrete
Januš, Ondřej ; Hradil, Petr (referee) ; Materna, Alois (referee) ; Štěpánek, Petr (advisor)
Recently, FRP (fibre reinforced polymers) materials are increasingly used in concrete structures, both for the strengthening of existing structures and as an internal reinforcement of concrete elements. It is due to convenient mechanical and physical properties of this kind of material. However, the use of these innovative materials as a reinforcement of concrete structures often requires a modification of the design process used for steel reinforcement. At present, a large number of bridge structures are in a very poor condition and require remediation due to corrosion of the steel reinforcement. Composite reinforcement appears to be a suitable alternative to steel reinforcement in these application areas. However, since bridge decks are directly exposed to repeated traffic loads, fatigue assessment is an important and often crucial part of the design. The number of studies dealing with the fatigue behaviour of internal FRP reinforcement is currently very limited. In particular, there is currently no study that sufficiently deals with the comprehensive determination of the effect of fatigue loading on the bond between FRP reinforcement and concrete. The doctoral thesis deals with the design of concrete elements reinforced with modern composite FRP reinforcement exposed to high-cyclic (fatigue) loading. Thanks to the performed extensive experimental programme, it was possible to determine the permissible limit values of fatigue load to ensure the required fatigue life. Based on these limiting values, the design and subsequent fatigue testing of full-scale concrete roofing slabs intended for aggressive environments was performed.
Self-assembled polymer systems responsive to external stimuli for biomedicine
Sincari, Vladimir ; Štěpánek, Petr (advisor) ; Matějíček, Pavel (referee) ; Sedláková, Zdeňka (referee)
The first work in my doctoral thesis described a novel rapid and eco-friendly reversible addition-fragmentation chain transfer (RAFT) polymerization reaction of the N-(2- hydroxypropyl) methacrylamide (HPMA) monomer under microwave irradiation (MWI). Optimal conditions for the polymerization such as reaction time, solvents, monomer stoichiometry and RAFT agents was determined. The polymerization kinetics demonstrated the linear increase in the number-average molecular weight (Mn) with monomer conversion. Good agreement between the theoretical and experimental Mn values was verified with pseudo-first- order kinetic plots, with low dispersities (Đ ≤ 1.04). Furthermore, this publication demonstrated the ability of MWI to facilitate copolymer formation by the preparation of relevant copolymers, such as poly(HPMA-b-bocAPMA), poly(HPMA-b-MABH) and poly(HPMA-b-PDPA) which were used as a base for the following work in the thesis. The second and third study are devoted to delivery of therapeutic molecules by using cargo-delivery self-assemblies in the form of polymersomes (PS). Such drug delivery systems (DDS) potentially minimize the premature degradation of drug, fast clearance from bloodstream and dosing frequency which leads to lower toxicity. The main advantage of DDS is the controlled manner of drug...
Stochastic optimization of reinforced concrete structures
Venclovský, Jakub ; prof. Ing. Alois Materna, CSc., MBA (referee) ; Popela,, Pavel (referee) ; Štěpánek, Petr (advisor)
This Ph.D. thesis deals with creating an algorithm for stochastic optimization of the cross-sectional parameters of flat frames. After a brief introduction and outline of the thesis' goals is the summary of knowledge and results in the areas of deterministic and stochastic structural optimization. Further, the task of deterministic optimization is described, as it was solved in the previous thesis and papers which this thesis follows up on. Afterwards, the reformulation of the deterministic task to its stochastic form is described and the solution algorithm for such a task is introduced. The thesis ends with results of using the introduced algorithm on 6 examples.

National Repository of Grey Literature : 184 records found   1 - 10nextend  jump to record:
See also: similar author names
30 ŠTĚPÁNEK, Petr
1 Štěpánek, P.
2 Štěpánek, Pavel
2 Štěpánek, Přemysl
Interested in being notified about new results for this query?
Subscribe to the RSS feed.