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14182. Turbulence characteristics of favorable pressure gradient flows in gravel-bed channel with vegetated walls
- Creator:
- Najafabadi, Elham Fazel, Afzalimehr, Hossein, and Sui, Jueyi
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- favorable pressure gradient flow, vegetation, gravel, quadrant analysis, stress fraction, and Reynolds stress
- Language:
- Slovak
- Description:
- Field observations showed that in many gravel-bed rivers, rice stems and gravel interact with each other and affect the flow structure. This calls to conduct research in more details in laboratory to better understand impacts of interaction between rice stems and gravel bed rivers on the flow structure. The outcome of such investigations can improve the estimation of drag coefficient in hydrodynamic models. Experiments were carried out in a flume with gravel bed and the vegetated vertical flume walls to investigate turbulence characteristics under favorable pressure gradient flows. Results showed that the stress fraction involves both the sweep and ejection dominance near the vegetated flume walls, showing no negative Reynolds shear stress near water surface. The values of exuberance ratio play a significant role on the magnitude of the Reynolds shear stress which varies with the distance from the vegetation. Quadrant analysis reveals that a major part of the momentum flux is transported during a short period of strong turbulence activity near the bed at the central axis. Augmentation of the hole size makes difference between contributions of sweep and ejection with those of the outward and inward interactions near the bed, however, the hole size doesn’t play any role near the water surface.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
14183. Turbulence modulation in Large Eddy Simulation of backward-facing step flow laden with particles
- Creator:
- Volavý, Jaroslav and Jícha, Miroslav
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- turbulence, Large Eddy Simulation, flow, and particles
- Language:
- English
- Description:
- This work describes Large Eddy Simulation of backward-facing step flow laden with particles. The concentration of the particles in the flow is high enough for consideration of two-way coupling. This means that the particles are influenced by fluid and vice versa. The inter-particle collisions are neglected. The Euler-Lagrange method is adopted which means that the fluid is considered to be continuum (Euler approach) and for each individual particle is solved Lagrangian equation of motion. Particles are considered to be spherical. The simulations are performed for different volume fractions. The results are compared to the single-phase flow in order to investigate the effect of the particles on the turbulence statistics of the carrier phase. and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
14184. Turnover of D1 protein encoded by psbA gene in higher plants and cyanobacteria sustains photosynthetic efficiency to maintain plant productivity under photoinhibitory irradiance
- Creator:
- Singh, M.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- irradiation stress, lincomycin, photosynthesis, protein synthesis and degradation, recovery, and Synechocystis
- Language:
- Multiple languages
- Description:
- The photosynthesis and related plant productivity aspects of plants and cyanobacteria depend upon the functioning of photosystem 2 (PS2), associated with D1 and D2 heterodimer reaction centre core proteins. The D1 protein is encoded by psbA gene, genetically localized on the plastid genome (cpDNA), contains functional cofactors of PS2 in association with D2 protein, and also functions for radiant energy transformation through oxidation of water and reduction of plastoquinone. Surprisingly, D1 protein accounts for even less than 1% of the total thylakoid membrane protein content. In spite of that, its rate of turnover is very much comparable to ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBPCO) large subunit, most abundantly present in green tissue. The normal functioning of PS2 possesses damage-repair cycles of D1 protein. Generally, rate of photodamage does not exceed the rate of repair under optimal growth conditions, therefore, no adverse effect on photosynthetic efficiency is manifest. However, under strong irradiance coupled with elevated temperature, level of photodamage exceeds the rate of repair, resulting in photoinhibition, photodegradation of D1 protein, and lowering photosynthetic efficiency linked with plant productivity eventually. The features of D1 turnover process are reviewed, particularly with respect to molecular mechanisms.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
14185. Tvorba etnografického názvosloví: (Zásady vytváření pojmů pro muzejní definiční slovník předmětů lidové hmotné kultury)
- Creator:
- Vondruška, Vlastimil
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- folklore studies, material folk culture, systematic collection data, and professional terminology
- Language:
- Czech
- Description:
- Autor článku je uveden se zkratkou křestního jména V.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
14186. Tvorba plazmonických nanostruktur na elektricky nevodivých substrátech pomocí elektronové litografie
- Creator:
- Babocký, Jiří, Bok, Jan, Šikola, Tomáš, and Fiala, Jiří
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- plasmonics, plasmonic antenna, electron lithography, electron microscopy of nonconductive samples, spectroscopy, plazmonika, plazmonická anténa, elektronová litografie, elektronová mikroskopie nevodivých vzorků, and spektroskopie
- Language:
- Czech
- Description:
- Fabrication of plasmonic nanoantennas with resonance frequencies in visible range is often challenging due to the necessity of exposure of nonconductive substrates. This work is focused in comparison of conventional fabrication approach using conductive polymer layers and alternative variable pressure electron beam lithography (VP-EBL) method. We have also studied the stability of VP-EBL process for long exposures. and Výroba plazmonických nanoantén s rezonančními frekvencemi ve viditelné oblasti pomocí elektronové litografie mnohdy přináší nutnost expozice nevodivých substrátů. Tato práce je zaměřena na porovnání výsledků dosažitelných konvenčním přístupem za použití vodivých polymerů a alternativního postupu v podobě litografie za variabilního tlaku (VP-EBL). Dále je testována stabilita VP-EBL procesu pro dlouhodobé expozice.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
14187. Twenty-four hour blood pressure profile in subjects with different subtypes of primary aldosteronism
- Creator:
- Tomáš Zelinka and Jiří Widimský
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, krevní tlak, blood pressure, ambulatory blood pressure monitoring, primary aldosteronism, circadian blood pressure variability, 14, and 612
- Language:
- English
- Description:
- The aim of our study was to evaluate the potential differences in blood pressure (BP) profile in subjects with different forms of primary aldosteronism (PA). Simultaneously, we studied the effects of PA treatment on BP curve. We therefore monitored 24-hour ambulatory blood pressure values in 22 subjects with aldosterone-producing adenoma (APA), 22 subjects with idiopathic hyperaldosteronism (IHA) and 33 subjects with essential hypertension (EH) as controls. We found a significantly attenuated nighttime systolic BP decline in the APA group (P=0.02). Patients with IHA had lower nighttime systolic BP values (P=0.01) and also a diastolic BP decline (P=0.02) during the night in comparison with EH. We did not detect any significant differences in BP profile characteristics between APA and IHA. Specific treatment of primary aldosteronism (adrenalectomy, treatment with spironolactone) led to the normalization of the BP curve with a marked BP decline. Our study thus demonstrates a blunted diurnal BP variability in patients with primary aldosteronism the specific treatment of which normalized previously attenuated nocturnal BP fall., T. Zelinka, J. Widimský., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
14188. Twin-disc experimental device for study of adhesion in wheel-rail contact
- Creator:
- Galas, Radovan, Smejkal, David, Omasta, Milan, and Hartl, Martin
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- wheel/rail contact, adhesion curve, twin-disc, and traction
- Language:
- English
- Description:
- In order to understand friction processes in wheel/rail contact a new experimental device has been developed. Twin-disc approach has been used to determine adhesion curves in wheel-rail contact under various conditions. This paper describes some details about the design of the twin-disc experimental device. Finally, preliminary results are discussed. and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
14189. Two concepts of a lie: Václav Havel on living in a communist regime
- Creator:
- Krása, Ondřej
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Václav Havel, truth, lie, dissent, Jan Patočka, and underground
- Language:
- Czech
- Description:
- According to Václav Havel’s famous essay The Power of powerless life within a lie is at the core of the communist regime in Czechoslovakia. Life within a lie is characteristic for the great majority of people and is contrasted with life within the truth which is characteristic of dissent movement. In this paper, I will try to shed some light on the concept of “living within a lie.” I will show that Havel develops not one but two concepts of a lie: on the one hand, lie is deliberate pretence; on the other hand, lie is seduction by consumerist values. The first meaning of a lie is derived from Havel’s analysis of the specifics of the Soviet sphere of influence, namely central role of ideology with omnipresent demands on public support of the regime. The second meaning of a lie is heavily influenced by a critical assessment of modern society from the leading figure of the Czech underground movement Ivan Jirous and leading Czech philosopher Jan Patočka. This double meaning of a lie enables Havel to capture both specific problems of living under the communist regime and general problems of living in modern society anywhere in the world. In the final chapters of this paper, I will show that Havel is not clear about how these two meanings of a lie are connected and that there are problems resulting from these unclarities both for Havel’s analysis of the communism and his proposed solution of the crisis.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
14190. Two innovative methods of dike monitoring
- Creator:
- Pařílková, Jana and Krejčí, Ivan
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- dike, thermistor, electrical impedance, ochranná hráz, termistor, and elektrická impedance
- Language:
- Slovak
- Description:
- Two original electrical methods of dikes monitoring (temperature scalar field and electrical impedance spectrometry) are described in detail. Using these methods, the non-stationary movement of the free water level in the dike can be indicated. The methods also enable to detect the piping in the dike due to the activity of animals. Some results are shown and discussed. and V příspěvku jsou uvedeny dvě neinvazivní metody (metoda měření teplotního skalárního pole a elektrické impedanční spektrometrie), které byly laboratorně ověřeny při monitorování nestacionárního pohybu volné hladiny vody v ochranných hrázích. Tyto metody navržené a ověřené autory příspěvku rovněž umožňují detekovat objemové změny (velikost nádrže při přelití koruny hráze, působení drobných živočichů apod.) konstrukce ochranné hráze. Některé ze získaných výsledků jsou zde uvedeny a diskutovány.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public