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32. Accuracy of radar-estimated precipitation in a mountain catchment in Slovakia
- Creator:
- Sleziak, Patrik, Jančo, Martin, Danko, Michal, Méri, Ladislav, and Holko, Ladislav
- Format:
- počítač and online zdroj
- Type:
- model:article and TEXT
- Subject:
- radar-estimated precipitation, precipitation estimates, daily precipitation, and synoptic weather situations
- Language:
- Slovak
- Description:
- Accurate estimation of precipitation in mountain catchments is challenging due to its high spatial variability and lack of measured ground data. Weather radar can help to provide precipitation estimates in such conditions. This study investigates the differences between measured and radar-estimated daily precipitation in the mountain catchment of the Jalovecký Creek (area 22 km2, 6 rain gauges at altitudes 815–1900 m a.s.l.) in years 2017–2020. Despite good correlations between measured and radar-based precipitation at individual sites (correlation coefficients 0.68–0.90), the radar-estimated precipitation was mostly substantially smaller than measured precipitation. The underestimation was smaller at lower altitude (on average by –4% to –17% at 815 m a.s.l.) than at higher altitudes (–35% to –59% at 1400–1900 m a.s.l.). Unlike measured data, the radar-estimated precipitation did not show the differences in precipitation amounts at lower and higher altitudes (altitudinal differences). The differences between the measured and radar-estimated precipitation were not related to synoptic weather situations. The obtained results can be useful in preparation of more accurate precipitation estimates for the small mountain catchments.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
33. Adaptive stochastic management of the storage function for a large, open reservoir using learned fuzzy models
- Creator:
- Kozel, Tomas and Stary, Milos
- Format:
- počítač and online zdroj
- Type:
- model:article and TEXT
- Subject:
- stochastic, artificial intelligence, storage function, and optimisation
- Language:
- Slovak
- Description:
- The design and evaluation of algorithms for adaptive stochastic control of the reservoir function of a water reservoir using an artificial intelligence method (learned fuzzy model) are described in this article. This procedure was tested on the Vranov reservoir (Czech Republic). Stochastic model results were compared with the results of deterministic management obtained using the method of classical optimisation (differential evolution). The models used for controlling of reservoir outflow used single quantile from flow duration curve values or combinations of quantile values from flow duration curve for determination of controlled outflow. Both methods were also tested on forecast data from real series (100% forecast). Finally, the results of the dispatcher graph, adaptive deterministic control and adaptive stochastic control were compared. Achieved results of adaptive stochastic management were better than results provided by dispatcher graph and provide inspiration for continuing research in the field.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
34. Adsorpcia arzeničnanov na pôdach: štúdium rýchlosti adsorpcie a adsorpčných izoteriem
- Creator:
- Hiller, Edgar
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- adsorption, freundlich isotherm, arsenates, kinetic equation, adsorpcia, Freundlichova izoterma, arzeničnany, and rýchlostná rovnica
- Language:
- Slovak
- Description:
- Kinetic and equilibrium studies of adsorption of arsenates As(V) were investigated in four soils from Slovakia. Using experimentally obtained adsorption isotherms of arsenates, the effect of selected soil properties on its adsorption was studied. The rate of As(V) adsorption was evaluated by three simple kinetic models: Elovich equation, modified Freundlich isotherm and pseudo-second order equation. It can be stated from experimentally obtained and calculated data that an increase in the initial As(V) concentration in solution resulted in a drop in the rate of As(V) adsorption and an increase in the time necessary for an attainment of the adsorption equilibrium. Results from equilibrium studies of As(V) adsorption fitted well to the Freundlich isotherm. The comparison of Freundlich coefficient kF with selected soil properties showed that capacity of particular soil for As(V) retention increased with increasing calcium carbonate content in given soil. The relation between CaCO3 content and kF coefficient was supported by highly positive correlation of dependence kF vs CaCO3, with R2 = 0.868. and Na štúdium rýchlosti adsorpcie arzeničnanov As(V) a ich adsorpčných izoteriem boli použité štyri vzorky pôd. Pomocou experimentálne získaných adsorpčných izoteriem As(V) bol sledovaný aj vplyv niektorých pôdnych vlastností na rozsah adsorpcie As(V). Rýchlosť adsorpcie As(V) bola zhodnotená použitím troch jednoduchých rýchlostných rovníc: Elovichovej rovnice, modifikovanej Freundlichovej izotermy a kinetickej rovnice pseudo-druhého poriadku. Namerané a vypočítané výsledky zo štúdia rýchlosti adsorpcie dokumentujú, že s rastúcou počiatočnou koncentráciou As(V) vo vodnom roztoku sa adsorpčná rýchlosť znížila a čas potrebný na dosiahnutie adsorpčnej rovnováhy sa zvýšil. Experimentálne získané adsorpčné izotermy As(V) veľmi dobre vyhovovali Freundlichovej adsorpčnej izoterme. Zo sledovaných chemických a fyzikálnych vlastností pôd mal na koeficient kF najväčší vplyv obsah uhličitanu vápenatého (CaCO3). Vzťah medzi obsahom CaCO3 a koeficientom kF sa potvrdil vysoko pozitívnou koreláciou (R2 = 0,868).
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
35. Aerodynamické modelování nesymetrických revitalizačních prvků v korytech upravených malých vodních toků
- Creator:
- Havlík, Aleš
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- river restoration, diversity of flow conditions, flow capacity of channel, revitalizace, kapacita koryta, and diversifikace proudění
- Language:
- Slovak
- Description:
- Due to renaturalization of trained watercourses, the capacity of the channel is often reduced. This paper deals with influence of non-symetrical obstacles placed into channels of small trained streams upon flow characteristics. In the framework of hydraulic research on aerodynamical model, four types of obstacles of various shape were used. An evaluation of their influence on total channel resistance in dependence on depth of flow and a spacing of the obstacles is presented. and Vlivem revitalizačních zásahů do upravených vodních toků zpravidla dochází ke zmenšení kapacity koryta. Předkládaný článek se zabývá vlivem nesymetrických revitalizačních prvků, vkládaných do upravených koryt malých vodních toků, na charakter proudění. V rámci fyzikálního výzkumu na aerodynamickém modelu byly použity 4 typy prvků, které různým způsobem zasahovali do průtočného profilu. V tomto článku je zhodnocen jejich vliv na celkové odpory koryta v závislosti na hloubce proudění a vzdálenosti prvků.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
36. Again an anniversary of Vít Klemeš
- Creator:
- Svoboda, Aleš
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Language:
- Slovak
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
37. Aleš Svoboda osemdesiatnikom
- Creator:
- Novák, Viliam
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Language:
- Slovak
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
38. An automated microinfiltrometer to measure small-scale soil water infiltration properties
- Creator:
- Gordon, Dennis C. and Hallett, Paul D.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- tension infiltrometer, water sorptivity, automated measurements, and small-scale infiltration measurements
- Language:
- Slovak
- Description:
- We developed an automated miniature constant-head tension infiltrometer that measures very small infiltration rates at millimetre resolution with minimal demands on the operator. The infiltrometer is made of 2.9 mm internal radius glass tube, with an integrated bubbling tower to maintain constant negative head and a porous mesh tip to avoid air-entry. In the bubbling tower, bubble formation and release changes the electrical resistance between two electrodes at the air-inlet. Tests were conducted on repacked sieved sands, sandy loam soil and clay loam soil, packed to a soil bulk density ρd of 1200 kg m-3 or 1400 kg m-3 and tested either air-dried or at a water potential ψ of -50 kPa. The change in water volume in the infiltrometer had a linear relationship with the number of bubbles, allowing bubble rate to be converted to infiltration rate. Sorptivity measured with the infiltrometer was similar between replicates and showed expected differences from soil texture and ρd, varying from 0.15 ± 0.01 (s.e.) mm s-1/2 for 1400 kg m-3 clay loam at ψ = -50 kPa to 0.65 ± 0.06 mm s-1/2 for 1200 kg m-3 air dry sandy loam soil. An array of infiltrometers is currently being developed so many measurements can be taken simultaneously.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
39. An inferentialist account of fictional names
- Creator:
- Lee, Byeong D.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- fictional names, inferentialist semantics, the anaphoric theory of reference, Sellars, and Brandom
- Language:
- Slovak
- Description:
- The goal of this paper is to present and defend an inferentialist account of the meaning of fictional names on the basis of Sellars-Brandom’s inferentialist semantics and a Brandomian anaphoric theory of reference. On this inferentialist account, the meaning of a fictional name is constituted by the relevant language norms which provide the correctness conditions for its use. In addition, the Brandomian anaphoric theory of reference allows us to understand reference in terms of anaphoric word-word relations, rather than substantial word-world relations. In this paper I argue that this inferentialist account has many important merits over its rival theories. One important merit is that it explains why we can use fictional names to make true statements, even if they lack bearers. As a consequence, this theory allows us to use fictional names without committing ourselves to an implausible ontology of fictional entities. Another important merit is that it provides a uniform semantic account of fictional names across different types of statements in which fictional names are involved.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
40. An influence of changing the humic acids content on soil water repellency and saturated hydraulic conductivity
- Creator:
- Babejová, Natália
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- water repellency, saturated hydraulic conductivity, humic acids, vodoodpudivosť, nasýtená hydraulická vodivosť, and humínové kyseliny
- Language:
- Slovak
- Description:
- An influence of changing the humic acids content on soil water repellency and saturated hydraulic conductivity was studied on soil samples of Mollic Gleysol from Cilizska Radvan in the Danubian Lowland. Water repellency was measured with the water drop penetration time (WDPT) test on original soil samples and on soil samples with increased humic acids content. Saturated hydraulic conductivity coefficient was measured on the above-mentioned samples with falling head permeameter. From the results of measuring it follows that an increasing of humic acids content in soil resulted in an decreasing of the coefficient of saturated hydraulic conductivity of the soil under study. Original soil was non-water reppelent soil. Already a small increasing of humic acids content in soil (in 17.9 % at original amount) caused that the soil became slightly or strongly water repellent in the average of soil moisture 15-30 %. At soil moisture less than 15 % time of penetration decreased probably as a result of shrinking and cracking of the soil. Water repellency of soil samples from horizon 0 - 5 cm was usually higher than water repellency of soil samples from horizon 5 - 10 cm both in case of humic acids extracted from peat and in case of humic acids extracted from the same soil from Cilizska Radvan. and Na pôdnej vzorke čiernice glejovej (ČA G) (MKSP, 2000) z lokality Čiližská Radvaň v Podunajskej nížině bol skúmaný pomocou testu času vsaku kvapky vody (WDPT test) vplyv zmeny obsahu humínových kyselin na vodoodpudivosť a nasýtenú hydraulickú vodivosť pôdy. Vodoodpudivosť bola meraná na pôvodných pôdnych vzorkách a vzorkách zo zvýšeným obsahom humínových kyselín. Koeficient nasýtenej hydraulickej vodivosti bol meraný na týchto pôdnych vzorkách metódou premenlivého hydraulického sklonu. Z nameraných výsledkov vyplýva, že nárast obsahu humínových kyselín v pôde mal za následok pokles koeficientu nasýtenej hydraulickej vodivosti študovanej pôdy. Už malé zvýšenie obsahu humínových kyselín v pôde (o 17,9 % pôvodnej hodnoty ) spôsobilo, že pôda sa stala slabo až silne vodoodpudivou vo vlhkostnom rozsahu 15-30 %. Pri pôdnej vlhkosti nižšej ako 15 % sa čas vsakovania zmenšil pravdepodobne v dôsledku zmršťovania pôdy a vzniku puklín. Vodoodpudivosť pôdnych vzoriek z horizontu 0 - 5 cm vo väčšine prípadov bola vyššia než vodoodpudivosť pôdnych vzoriek z horizontu 5 - 10 cm aj v prípade pridania humínových kyselín, extrahovaných z rašeliny, aj v prípade pridania humínových kyselín, extrahovaných z tej istej pôdy.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public