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422. Finding behavioral parameterization for a 1-D water balance model by multi-criteria evaluation
- Creator:
- Casper, Markus C., Mohajerani, Hadis , Hassler, Sibylle , Herdel, Tobias , and Blume, Theresa
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- forest evapotranspiration, water balance simulation, soil parameterization, and behavioral model
- Language:
- Slovak
- Description:
- Evapotranspiration is often estimated by numerical simulation. However, to produce accurate simulations, these models usually require on-site measurements for parameterization or calibration. We have to make sure that the model realistically reproduces both, the temporal patterns of soil moisture and evapotranspiration. In this study, we combine three sources of information: (i) measurements of sap velocities; (ii) soil moisture; and (iii) expert knowledge on local runoff generation and water balance to define constraints for a “behavioral” forest stand water balance model. Aiming for a behavioral model, we adjusted soil moisture at saturation, bulk resistance parameters and the parameters of the water retention curve (WRC). We found that the shape of the WRC influences substantially the behavior of the simulation model. Here, only one model realization could be referred to as “behavioral”. All other realizations failed for a least one of our evaluation criteria: Not only transpiration and soil moisture are simulated consistently with our observations, but also total water balance and runoff generation processes. The introduction of a multi-criteria evaluation scheme for the detection of unrealistic outputs made it possible to identify a well performing parameter set. Our findings indicate that measurement of different fluxes and state variables instead of just one and expert knowledge concerning runoff generation facilitate the parameterization of a hydrological model.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
423. Flattening the curve of moral imagination
- Creator:
- Beran, Ondřej
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- COVID-19 crisis, economic concerns, moral dilemmas, moral luck, and remorse
- Language:
- Slovak
- Description:
- In this paper, I discuss some moral dilemmas related to the COVID-19 crisis and their framing (mainly) in the public debate. The key assumption to engage with is this: that we need primarily to take into account the long-term economic consequences of the proposed safety measures of social distancing. I argue that the long-term economic concerns, though legitimate, cannot suspend the irreducibly moral nature of the demand placed on the decision-makers by those who are vulnerable, at risk, or in need of medical treatment. This is discussed in relation to two points: 1) The political endeavour and rhetoric of “flattening the curve” is not necessarily short-sighted but expresses the acknowledgment of a legitimate expectation placed on elected representatives. 2) Not being able to prevent harm (to those who are in real need, or otherwise vulnerable) may lead to genuine moral distress, even if it is not clear whether it was in one’s, or anybody’s, powers to prevent the situation, or even if the best possible outcome has been otherwise reached. The second point may be understood as a part of the broader context of the established criticisms of utilitarianism.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
424. Flood regime of rivers in the Danube River basin
- Creator:
- Pekárová, Pavla
- 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
425. Floods effects on rivers morphological changes application to the Medjerda River in Tunisia
- Creator:
- Gharbi, Mohamed, Soualmia, Amel, Dartus, Denis, and Masbernat, Lucien
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- floods, hydrodynamics, sediment transport, modelling, and river morphology
- Language:
- Slovak
- Description:
- In Tunisia especially in the Medjerda watershed the recurring of floods becoming more remarkable. In order to limit this risk, several studies were performed to examine the Medjerda hydrodynamic. The analysis of results showed that the recurrences of floods at the Medjerda watershed is strongly related to the sediment transport phenomena. Initially, a one dimensional modelling was conducted in order to determine the sediment transport rate, and to visualize the river morphological changes during major floods. In continuity of this work, we will consider a two-dimensional model for predicting the amounts of materials transported by the Medjerda River. The goal is to visualize the Medjerda behaviour during extreme events and morphological changes occurred following the passage of the spectacular flood of January 2003. As a conclusion for this study, a comparative analysis was performed between 1D and 2D models results. The objective of these comparisons is to visualize the benefits and limitations of tested models. The analysis of the results demonstrate that 2D model is able to calculate the flow variation, sediment transport rates, and river morphological changes during extreme events for complicated natural domains with high accuracy comparing with 1D Model.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
426. Flow characteristics at trapezoidal broad-crested side weir
- Creator:
- Říha, Jaromír and Zachoval, Zbyněk
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- broad-crested side weir, experimental research, flow characteristics, and hydraulics
- Language:
- Slovak
- Description:
- Broad-crested side weirs have been the subject of numerous hydraulic studies; however, the flow field at the weir crest and in front of the weir in the approach channel still has not been fully described. Also, the discharge coefficient of broad–crested side weirs, whether slightly inclined towards the stream or lateral, still has yet to be clearly determined. Experimental research was carried out to describe the flow characteristics at low Froude numbers in the approach flow channel for various combinations of in- and overflow discharges. Three side weir types with different oblique angles were studied. Their flow characteristics and discharge coefficients were analyzed and assessed based on the results obtained from extensive measurements performed on a hydraulic model. The empirical relation between the angle of side weir obliqueness, Froude numbers in the up- and downstream channels, and the coefficient of obliqueness was derived.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
427. Flow characteristics of rectangular broad-crested weirs with sloped upstream face
- Creator:
- Goodarzi, Ehsan, Farhoudi, Javad, and Shokri, Naser
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- broad crested weir, upstream face slope, flow surface pattern, discharge coefficient, correction factor, separation zone, velocity profile, priepad širokou priepadovou hranou, sklon návodného povrchu, tvar povrchu hladiny, výtokový koeficient, korekčný faktor, oblasť separácie, and profily rýchlosti prúdenia
- Language:
- Slovak
- Description:
- The hydraulic characteristics of flow over rectangular broad-crested weirs with varying upstream slopes were experimentally studied. A series of laboratory experiments was performed to investigate the effects of changing upstream slopes from 90º to 75º, 60º, 45º, 30º, 22.5º, 15º, and 10º on the flow surface pattern, discharge coefficient values, approach velocity profile and flow separation zone. In addition, a new mathematical relationship for water surface profile and a new correction factor to estimate discharge coefficient over weirs with various upstream slopes were introduced. The results showed decreasing upstream slopes from 90º to 10º leading to increasing discharge coefficient values and dissipation of the separation zone. and Práca obsahuje výsledky experimentálneho štúdia prietoku vody cez pravouhlý priepad so širokou priepadovou hranou s rozdielnymi sklonmi návodného povrchu priepadu. Uskutočnili sme sériu laboratórnych pokusov s cieľom štúdia vplyvu rôznych sklonov návodného povrchu priepadu od 90°, 75°, 60°, 45°, 30°, 22,5°, 15°, až po 10° na tvar hladiny, hodnoty prietokového súčiniteľa, rýchlostné profily a na prúdenie v oblasti separácie. Okrem toho boli zistené nové matematické vzťahy na výpočet tvaru hladiny, ako aj nové korekčné faktory na určenie prietokových súčiniteľov cez priepad s rozdielnymi sklonmi návodného povrchu. Z výsledkov vyplýva, že znižujúce sa sklony návodného povrchu priepadu od 90° po 10° vedú k zvýšeniu prietokového súčiniteľa a k disipácii oblasti separácie.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
428. Flow measurement in the model pump suction sump with baffle by means of LDV and PIV
- Creator:
- Mansa, Kante, Yulin, Wu, Yong, Li, Xiaoming, Li, and Yu, Xu
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- PIV, LDV, flow in pump suction area, velocity measurement, proudění v sací jímce, and měření rychlostí
- Language:
- Slovak
- Description:
- The cavitations in turbo-machines decrease their efficiency and have a bad impact of their work-life and therefore constructors are always trying to avoid or minimize the cavitation risks in hydraulic machines. In this paper we have done the LDV measurement of flow in the model pump suction sump with baffle. In precedent works we did the PIV (Particles Image Velocimetry) measurement with and without baffle. Around the pump bell there are very complex vortices, which can affect seriously the flow characteristics of the pump. They can also cause vibrations, cavitations and decrease the efficiency of the system. In this experiment the pump suction sump and the pump bell with particular structure are used to search the flow situation in the surrounding of the bell. Both LDV and PIV experiments were done with steady flow using appropriate materials. and Kavitace v turbogenerátorech a čerpacích systémech snižuje jejich účinnost a negativně ovlivňuje jejich životnost. Snahou konstruktérů je proto vyloučit nebo minimalizovat riziko kavitace v hydraulických strojích. V článku jsou prezentována měření rychlostních polí pomocí LDV v modelové sací jímce s tokovým usměrňovačem a výsledky jsou porovnány s dřívějšími měřeními pomocí PIV. V blízkosti sacího zvonu vznikají komplikované vírové struktury, které mohou následně ovlivňovat charakteristiku čerpadla a které mohou být příčinou vzniku vibrací, kavitace a snížení účinnosti. Pozornost proto byla zaměřena na měření rychlostních polí v okolí sacího zvonu.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
429. Flow structure of coarse-grained slurry in a horizontal pipe
- Creator:
- Vlasák, Pavel, Kysela, Bohuš, and Chára, Zdenek
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- coarse-grained slurry, turbulent flow, pressure drop, velocity distribution, flow structure, concentration effect, hrubozrnné suspenze, turbulentní proudění, tlakové ztráty, rozdělení rychlostí, struktura proudu, and vliv koncentrace
- Language:
- Slovak
- Description:
- The flow behaviour of coarse-grained slurry depends on particle size, shape, density and concentration, and on the density and rheological properties of the carrier liquid. The present paper describes the results of an experimental investigation and flow visualisation of model coarse-grained particle-water mixtures in a closed pipe loop with smooth stainless steel pipes of inner diameter 36 mm. Glass balls and washed graded pebble gravel of mean diameter d50 = 6 mm were used as model coarse-grained material. The effect of slurry velocity and particle concentration on the slurry flow behaviour and pressure drop in the turbulent regime was evaluated. Particle distribution in the pipe cross-section and motion of particles along the pipe invert, particle saltation and particle conveying in the carrier liquid were investigated in a transparent pipe viewing section and motion of individual particles was described. Velocity profiles of the carrier liquid and conveyed particles were determined. and Tokové chování hrubozrnných suspenzí závisí na velikosti, tvaru a hustotě částic, koncentraci pevné fáze a hustotě a reologických vlastnostech nosné kapaliny. Článek popisuje výsledky experimentálního výzkumu a vizualizace proudění modelové hrubozrnné suspenze v experimentální potrubní lince s hladkým nerezovým potrubím s vnitřním průměrem 36 mm. Skleněné kuličky a praný oblý štěrk (kačírek) se středním zrnem d50 = 6 mm byly použity jako modelový materiál. Byl vyhodnocen vliv rychlosti proudění suspenze a koncentrace pevné fáze na chování a tlakové ztráty suspenze. Rozdělení částic v příčném průřezu potrubí a pohyb částic podél dna potrubí, jejich saltace a unášení v nosné kapalině byly zkoumány v transparentní části potrubí a byl popsán pohyb jednotlivých částic a pro vybrané případy byly stanoveny rychlostní profily nosné kapaliny a unášených částic.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
430. Frege on identity and co-reference
- Creator:
- Corazza, Eros
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Frege, Perry, and identity co-reference
- Language:
- Slovak
- Description:
- In “Über Sinn und Bedeutung” (1892) Frege raises a problem concerning identity statements of the form a=b and he criticizes the view he holds in the Begriffsschrift (1879, § 8). In building on a suggestion by Perry (2001/12, ch. 7) I will show how Frege’s Begriffsschrift account can be rescued and how Frege’s 1892 criticism of his Begriffsschrift’s position somewhat miss the point. Furthermore, the Begriffsschrift’s view can be developed to account in quite an elegant way to the so-called Frege’s Puzzle without committing to the sense/reference (Sinn/Bedeutung) distinction Frege introduces in “Über Sinn und Bedeutung”. To do so we have, though, to give up the idea that all the relevant information conveyed by the utterance of a simple sentence is encapsulated into a single content. I will show of this can be done in adopting a Perry-style pluri-propositionalist model of communication.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public