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802. Analogické kvantové pohybové rovnice elektronových a fotonových vln v izotropních prostředích
- Creator:
- Pospíšil, Jaroslav and Pluháček, František
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- quantum physics, applied mathematics, kvantová fyzika, and aplikovaná matematika
- Language:
- Czech
- Description:
- The formulations and interpretations of some formally analogous expressions of the single-particle scalar quantum wave equations of electrons and photons, propagated in adequate isotropic static media under weak signals and interaction phenomena, are presented in this article. and V prezentovaném článku jsou obsaženy formulace a interpretace některých formálně analogických tvarů jednočásticových skalárních kvantových vlnových rovnic šířících se elektronů a fotonů v přiměřených izotropních statických prostředích při slabých signálech a interakčních jevech.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
803. Analogový elektro-optický přenosový systém pro účely měření
- Creator:
- Švarný, Jiří
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- analog systems, analog signal processing, measurement, analogové systémy, analogové zpracování signálů, měření, elektro-optický převodník, širokopásmový přenos, přenosový systém, externí modulace, LiNbO3 Mach-Zehnderův modulátor, and intenzitní modulace
- Language:
- Czech
- Description:
- The work deals with design and implementation of an analogue electro-optic transmission system convenient to solve some specialized tasks in the field of diagnostics and measurements. The proposed system is designed to solve several requirements that are beyond the limits of conventional metallic transmission medium. Especially it is the case of broadband transmission, extreme length of the transmission medium and high galvanic barrier between input and output that have to be achieved simultaneously. and Práce popisuje vývoj a realizaci analogového elektro-optického přenosového systému použitelného v některých speciálních případech diagnostiky a měření. Navržený přenosový systém řeší několik vzájemně se limitujících požadavků, které není možné standardním metalickým propojením splnit. Jde zejména o současné dosažení velké šířky frekvenčního pásma, délky přenosového média a dostatečné galvanické bariéry mezi vstupem a výstupem.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
804. Analyse and verification of in-pipe bristled minimachine prototype
- Creator:
- Dovica, Miroslav, Gorzás, Michal, Kaťuch, Peter, and Kováč, Jozef
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- thin pipe, minimachine, smart bristle, and difference friction
- Language:
- English
- Description:
- This paper describes experimental work done on a prototype of in-pipe bristled minimachine, which locomotes in pipe with inner diameter under 40 mm. The principle of minimachine locomotion is based on difference friction force between bristle tip and pipe wall. The new bristle design and its mathematical and graphical model will be presented. and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
805. Analysis of chlorophyll fluorescence decays of isolated thylakoids in various stages of greening
- Creator:
- Kowalczyk, A., Waloszek, A., and Frąckowiak, D.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- chloroplast, Cucumis sativus, 3-(3,4-dichlorophenyl)-1,1-dimethyl urea, etiochloroplast, fractal model, and photooxidation
- Language:
- Multiple languages
- Description:
- The decay of chlorophyll (Chl) fluorescence of etiochloroplasts isolated in various stage of greening of cucumber cotyledons was analysed in order to get structural information on a photosynthetic apparatus. Two model decays, multiexponential and stretched exponential, were applied in the analysis. The quality of fit in these two models was different in various stages of chloroplast greening. The two-exponent model did not provide a good fit at early greening stages. To improve the fit it was necessary to introduce an additional third component which became very low at later stages. However, chloroplasts in the early stage of greening could also be described by a stretched exponential with parameters indicating rather planar (two-dimensional) arrangement of donor and acceptor molecules. The chloroplasts treated by DCMU and/or photooxidized by strong irradiance exhibit a similar character of fractal decay as untreated samples but in the multiexponential model the exact values of lifetimes and amplitudes of components vary. This suggests that the structure of investigated system does not dramatically change as a result of these two types of treatment. and A. Kowalczyk, A. Waloszek, D. Frąckowiak.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
806. Analysis of diaphragm movement, during tidal breathing and during its activation while breath holding, using MRI synchronized with spirometry
- Creator:
- Kolář, P., Jiří Neuwirth, Jan Šanda, Vojtěch Suchánek, Zuzana Svatá, J. Volejník, and Martin Pivec
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, držení těla, physiology, posture, diaphragm fiction, magnetic resonance Paging, thorax, 14, and 612
- Language:
- English
- Description:
- a1_Using magnetic resonance imaging (MRI) in conjunction with synchronized spirometry we an alyzed and compared diaphragm movement during tidal breathing and voluntary movement of the diaphragm while breath holding. Breathing cycles of 16 healthy subjects were examined using a dynamic sequence (77 slices in sagittal plane during 20 s, 1NSA, 240x256, TR4.48, TE2.24, FA90, TSE1, FOV 328). The amplitude of movement of the apex and dorsal costophren ic angle of the diaphragm were measured for two test conditions: tidal breathing and voluntary breath holding. The maximal inferior and superior positions of the diaphragm were subtracted from the corresponding positions during voluntary movements while breath holding. The average amplitude of inferio-superior mo vement of the diaphragm apex during tidal breathing was 27.3±10.2 mm (mean ± SD), and during voluntary movement while breath holding was 32.5±16.2 mm. Movement of the costophrenic angle was 39±17.6 mm during tidal breathing and 45.5±21.2 mm during voluntary movement while breath holding. The inferior position of the diaphragm was lower in 11 of 16 subjects (68.75 %) and identical in 2 of 16 (12.5 %) subj ects during voluntary movement compared to the breath holding. Pearson’s correlation coefficient was used to demonstrate that movement of the costophrenic angle and apex of the diaphragm ha d a linear relationship in both examined situations (r=0.876). A correlation was found between the amplitude of diaphragm movement during tidal breathing and lung volume (r=0.876). The amplitude of movement of the diaphragm with or without breathing showed no correlation to each other (r=0.074). The moveme nt during tidal breathing shows a correlation with the changes in lung volumes. Dynamic MRI demonstrated that individuals are capable of moving their diaphragm voluntarily, but the amplitude of movement differs from person to person., a2_In this study, the movements of the diaphragm apex and the costophr enic angle were synchronous during voluntary movement of the diaphragm while breath holding. Although the sample is small, this study confirms that the function of the diaphragm is not only respiratory but also postural and can be voluntarily controlled., P. Kolář, J. Neuwirth, J. Šanda, V. Suchánek, Z. Svatá, J. Volejník, M. Pivec., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
807. Analysis of dominant factors influencing moisture change of broad-ovate leaves of Populus euphratica Oliv. in extremely arid region
- Creator:
- Fu, A. H., Li, W. H., Chen, Y. N., Zhu, C. G., and Ma, J. X.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- botanika, botany, environmental factors, extreme arid environment, gas exchange, Populus euphratica Oliv., and water potential
- Language:
- Multiple languages
- Description:
- We studied the dominant environmental factors that affect the gas-exchange characteristics and water potential (ψ) of broad-ovate leaves of Populus euphratica Oliv. in extreme arid area of Tarim River, China, and their correlation to water status of P. euphratica by analyzing on-field monitored meteorological data, soil moisture and salinity, P. euphratica leaf gas exchange and ψ, and revealed the indicative threshold of environmental factors for P. euphratica leaf water changes and growth. The results indicated that meteorological factors such as air relative humidity (RH), air temperature (T air), etc. are the dominant factors. The threshold value of RH is (48.19 ± 1.06)% for P. euphratica growth, i.e. RH from 10.69% to 48.19% is suitable for P. euphratica growth in extremely arid region of Tarim River. This study provides a theoretical basis for reducing drought damage to P. euphratica and maintaining normal growth of P. euphratica by in-time watering. and A. H. Fu ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
808. Analysis of efficiency of pollution reduction measures in rural basin using MIKE Basin model. Case study: Olšava River Basin
- Creator:
- Kaiglová, Jana and Langhammer, Jakub
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- water quality, modelling, rural basins, MIKE basin, non-point pollution, and land use
- Language:
- Slovak
- Description:
- This paper presents the results of testing the applicability of the MIKE Basin model for simulating the efficiency of scenarios for reducing water pollution. The model has been tested on the Olšava River Basin (520 km2 ) which is a typical rural region with a heterogeneous mix of pollution sources with variable topography and land use. The study proved that the model can be calibrated successfully using even the limited amount of data typically available in rural basins. The scenarios of pollution reduction were based on implementation and intensification of municipal wastewater treatment and conversion of arable land on fields under the risk of soil erosion to permanent grassland. The application of simulation results of these scenarios with proposed measures proved decreasing concentrations in downstream monitoring stations. Due to the practical applicability of proposed measures, these could lead to fulfilment of the water pollution limits required by the Czech and EU legislation. However, there are factors of uncertainty that are discussed that may delay or limit the effect of adopted measures in small rural basins.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
809. Analysis of extreme hydrological events on the danube using the peak over threshold method
- Creator:
- Bačová-Mitková, Veronika and Onderka, Milan
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Danube River, extreme hydrological events, flood frequency analysis, peaks over threshold (POT) method, daily runoff, return period, tok Dunaja, extrémne hydrologické udalosti, frekvencia výskytu povodní, metóda POT, denný prietok, and doba opakovania prietokov
- Language:
- Slovak
- Description:
- The Peak Over Threshold Method (POT) was used as an alternative technique to the traditional analysis of annual discharge maxima of the Danube River. The POT method was applied to a time-series of daily discharge values covering a period of 60 years (1931-1990) at the following gauge stations: Achleiten, Kienstock, Wien, Bratislava and Nagymaros. The first part of the paper presents the use of the POT method and how it was applied to daily discharges. All mean daily discharges exceeding a defined threshold were considered in the POT analysis. Based on the POT waves independence criteria the maximum daily discharge data were selected. Two theoretical log-normal (LN) and Log-Pearson III (LP3) distributions were used to calculate the probability of exceeding annual maximum discharges. Performance of the POT method was compared to the theoretical distributions (LN, LP3). The influence of the data series length on the estimation of the N-year discharges by POT method was carried out too. Therefore, with regard to later regulations along the Danube channel bank the 40, 20 and 10-year time data series were chosen in early of the 60-year period and second analysed time data series were selected from the end of the 60-year period. Our results suggest that the POT method can provide adequate and comparable estimates of N-year discharges for more stations with short temporal coverage. and Príspevok sa zaoberá analýzou extrémnych hydrologických udalostí na Dunaji metódou Peak Over Threshold (POT). Metóda POT sa používa ako alternatíva určovania N-ročných prietokov k metóde ročných maxím pri analýzach extrémnych hydrologických udalostí. Pre výskyt vrcholových prietokov sa zvyčajne predpokladá Poissonova distribúcia. Základnými vstupnými údajmi pre štatistickú analýzu sú 60-ročné časové rady priemerných denných prietokov a 60-ročné rady maximálnych ročných prietokov v nami zvolených staniciach: Achleiten, Kienstock, Viedeň, Bratislava a Nagymaros - za obdobie 1931-1990. Extrémne hydrologické udalosti na Dunaji boli analyzované metódou POT, ktorá zahŕňa všetky maximálne denné prietoky povodní za dané obdobie, presahujúce zvolenú prahovú hodnotu. Na zostavenie teoretickej čiary prekročenia boli vybrané dve teoretické rozdelenia pravdepodobnosti: logaritmicko-normálne rozdelenie (LN) a Pearsonovo rozdelenie III. typu (LP III). Druhým cieľom príspevku bolo analyzovať vplyv zmeny dĺžky časového radu na odhad N-ročných prietokov. V práci boli 60-ročné časové rady údajov skrátené na 40, 20 a 10-ročné rady. V závere sme porovnali a zhodnotili získané výsledky štatistických odhadov N-ročných prietokov vo zvolených staniciach. Z výsledkov analýzy vyplýva, že metóda POT dáva pomerne dobré odhady N-ročných prietokov aj pre krátke časové rady údajov.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
810. Analysis of field-scale salinization: a comparison of different modeling approaches
- Creator:
- Vaughan, P.J., Shouse, P.J., Suarez, D.L., van Genuchten, M.Th., and Ayars, J.E.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- solute transport, field simulation, chloride, Unsatchem, transport rozpustených látok, simulácia v poľných podmienkach, and chloridy
- Language:
- Slovak
- Description:
- Soil and groundwater salinization are major problems for irrigated agriculture in many arid and semiarid areas of the world. Studies addressing such problems require accurate estimation of salt loadings from irrigated areas through the vadose zone to underlying groundwater. We studied Cl- transport in the vadose zone at 45 locations in a field in the San Joaquin Valley, California, through a combination of soil sampling at six depths (0-1.8 m) and numerical modeling using a coupled water flow and solute transport code (Unsatchem). Our purpose was to assess water and salt loadings from the heterogeneous field to groundwater over a two-year period, and to test applicability of the code to the data. Soil sampling in November, 1995, defined the initial water content and the Cl- concentration, and the soil hydraulic properties. Four more sampling periods, ending in November 1997, provided data for evaluating model performance. Cl- distributions in 1997 exhibited a variety of shapes including monotonically increasing or decreasing distributions versus depth, and profiles with maxima or and sigmoidal shapes. The standard modeling approach, based on the Richards equation and the convection-dispersion equation, predicted more Cl- leaching than was observed in the field. Somewhat improved predictions were obtained when the potential transpiration rate was increased by a factor of 1.5. Better leaching predictions were also obtained when the model included separate mobile and immobile water fractions, mostly by improving the profile shapes. Our study shows the importance of accurate descriptions of the lower boundary conditions, spatial variability in the water infiltration rate, and estimation of soil surface evaporation and transpiration rates. and Zasoľovanie pôdy a podzemných vôd sú hlavnými problémami pôdohospodárstva v závlahových podmienkach v mnohých arídnych a semiarídnych oblastiach sveta. Štúdie, ktoré riešia podobné problémy, vyžadujú si presné určenie zaťaženia soľami zo závlah, ktoré prechádzajú nenasýtenou oblasťou pôdy do podzemných vôd. V tejto štúdii sa zaoberáme transportom Cl- v nenasýtenej oblasti pôdy v 45 lokalitách v San Joaquin Valley, California, využívajúc kombináciu odberu vzoriek pôdy v šiestich hĺbkach (0–1.8 m) a numericakým modelovaním s využitím simulačného modelu kombinovaného transportu vody a rozpustených látok (solí) (Unsatchem). Cieľom je určenie priesaku vody a rozpustených látok z heterogénneho poľa do podzemných vôd počas dvojročného obdobia a testovanie použiteľnosti uvedeného modelu vzhľadom k vstupným hodnotám. Zo vzoriek pôdy, odobratých v novembri 1995 bolo určené počiatočné rozdelenie vlhkosti pôdy a koncentrácia Cl- , ako aj hydraulické vlastnosti pôdy. Štyri ďalšie termíny odberov, končiac v novembri 1997, poskytli údaje pre overenie modelu. Rozdelenie Cl- v roku 1997 sa vyznačovalo rozdieľnosťou tvarov, vrátane monotónne klesajúceho alebo stúpajúceho rozdelenia koncentrácií v závislosti na hĺbke, ako aj profilmi s maximom, alebo aj sigmoidálneho tvaru. Štandardný modelový prístup, založený na Richardsovej rovnici a konvektívno-disperznej rovnici, predpovedal viac vyplaveného Clako bolo pozorované v poli. O niečo lepšie výsledky boli dosiahnuté, ak sa potenciálna transpirácia zvýšila 1,5-násobne. Lepšie výsledky v prognóze vyplavovania solí boli dosiahnuté, ak model obsahoval separátne mobilnú a imobilnú vodu, predpovšetkým zlepšením tvarov vertikálnych rozdelení koncentrácií chlóru. V tejto štúdii bolo ukázané, aké je dôležité presné určenie dolných okrajových podmienok, priestorovej variability rýchlosti infiltrácie, ako aj určenie výparu z povrchu pôdy a transpirácie.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public