Wyniki wyszukiwania - Biblioteka Nauki

1

Modelowe badania przepływu podczas obróbki strumieniem wodnym

100%

Szczepanik M.

Prace Naukowe Katedry Budowy Maszyn / Politechnika Śląska

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2009

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tom nr 1

217-236

PL

Artykuł przedstawia przebieg procesu modelowania oraz otrzymane wyniki zjawiska przepływu strugi wodnej przez dyszę wodną głowicy tnącej maszyny do obróbki strumieniem wodno-ściernym. Celem badań była analiza zachowania się strugi wodnej wewnątrz dyszy oraz w powietrzu po jej opuszczeniu, a także określenie współczynników jej rozbicia.

EN

The article presents course of modeling process and recived results of pure water flow through waterjet nozzle. The purpose of research was the analysis of waterjet behaviour inside nozzle channels and in the air, after it leaves the nozzle. Finally, extension factor of waterjet was determined.

2

Discriminating Between Different Streamflow Regimes by Using the Fisher-Shannon Method : An Application to the Colombia Rivers

86%

Pierini J. O. , Restrepo J. C. , Lovallo M. , Telesca L.

Acta Geophysica

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2015

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tom Vol. 63, no. 2

533--546

EN

The Fisher-Shannon (FS) information plane, defined by the Fisher information measure (FIM) and the Shannon entropy power (NX), was robustly used to investigate the complex dynamics of eight monthly streamflow time series in Colombia. In the FS plane the streamflow series seem to aggregate into two different clusters corresponding to two different climatological regimes in Colombia. Our findings suggest the use of the statistical quantity defined by the FS information plane as a tool to discriminate among different hydrological regimes.

3

Wpływ czasu przepływu strumienia produktów przez pętlę zwrotną na generację chaosu w reaktorze autotermicznym

72%

Berezowski M. , Grabski A. , Iwanowski J.

Inżynieria Chemiczna i Procesowa

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2001

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tom T. 22, z. 3B

241--246

PL

Praca niniejsza zawiera analizę teoretyczną wpływu czasu opóźnienia wnoszonego przez pętlę cieplnego sprzężenia zwrotnego na generację złożonej dynamiki rurowego reaktora autotermicznego. Wykazano możliwość wystąpienia chaosu w powyższym układzie.

EN

The present study deals with a theoretical analysis of the effect of delay time of heat transfer upon the generation of complex dynamics in a heat integrated tubular reactor. The importance of this time for the presence of chaos in a system is demonstrated.

4

Complexity analyses of Godavari and Krishna river streamflow using the concept of entropy

58%

Singh R. K. , Jain M. K.

Acta Geophysica

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2021

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tom Vol. 69, no. 6

2325--2338

EN

The hydrological regime in both the Godavari and Krishna River has been altered due to both human-induced and environmental changes. The present study utilizes the sample entropy and its more generalized approach known as multiscale entropy to investigate the temporal and spatial distribution of complexity and quantify them using SampEn values. Daily streamflow for five stations, three from Godavari River (Dhalegaon, Nowrangpur, and Polavaram), and two from Krishna River (Yadgir and K. Agraharam), was analysed for the complexity analyses. Trends in the streamflow for the selected gauging stations and their annual entropy values have also been evaluated using the Mann–Kendall test. The trend results revealed that three (Dhalegaon and Nowrangpur in Godavari basin and Yadgir in Krishna basin) out of five stations showed significant decreasing trends for both monthly and annual streamflow series. The declining trend in streamflow could be attributed to both anthropogenic (reservoir operation, increased water abstraction, etc.) and climatic (change in monsoon rainfall, temperature, etc.) factors. The most significant reduction in annual streamflow during the post-impact period was observed at Dhalegaon station in Godavari Basin (from 53,573 to 19,555 m3/s) signifying maximum alteration in annual flow regime. The entropy analysis results of streamflow showed that there was obvious spatial and temporal variation in the complexity, as indicated by the annual SampEn values. Although not profound, a negative correlation exists between the annual runoff and SampEn values (highest −0.42 at K. Agraharam) and hence a reverse correspondence exists between them. In MSE analysis, the original streamflow series increased with time scale (up to 30 days was chosen for this study), whereas entropy decreased with an increased time scale. Due to the fully operational state of the dams upstream of the gauging stations, the entropy values during the post-impact period were less the pre-impact period. The present study can be used as a scientific reference to use information science to detect hydrologic alterations in the river basins. Future studies should focus on considering both climatic and land-use changes in conjunction with the human-induced changes for more comprehensive river system disorder analysis.

5

The vortex dynamics in HTc superconductor in external magnetic field

51%

Sosnowski J.

Journal of Technical Physics

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2005

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tom Vol. 46, no 4

245-255

EN

The penetration of magnetic induction into HTc superconductors has been considered taking into account the layered structure of these materials. For magnetic field parallel to the planes a one-dimensional penetration has been considered, while in perpendicular magnetic field it is a two-dimensional problem. The flux creep equation has been considered, whose solution was confirmed by experimental data measured on an Y-Ba-Cu-O sample. The magnetic diffusion equation has been solved for a description of the magnetic induction profiles in an increasing external magnetic field. The dynamic anomalies of the current-voltage characteristics have been then predicted, in agreement with experimental observations. The model taking into account the influence of the vortex-pinning center interaction on the magnetic field dependence of the critical current, has been also applied successfully for description of the anomalies.