Wyniki wyszukiwania

1

Recent developments in studies of sediment transport in open channels

100%

Majewski W.

Zeszyty Naukowe Akademii Rolniczej we Wrocławiu. Melioracja

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1988

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nr 31

2

Flow of hydraulic mixtures and energy losses in channels of hydraulic transport systems

86%

Smoylovskaya L. A., Molochnikov L. N.

Zeszyty Naukowe Akademii Rolniczej we Wrocławiu. Melioracja

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1988

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nr 31

3

Channel-floodplain geomorphology and connectivity of the Lower Paraguay hydrosystem

72%

Drago E. C., Paira A. R., Wantzen K. M.

International Journal of Ecohydrology and Hydrobiology

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2008

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tom 08

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nr 1

The Paraguay River is the main tributary of the Paraná River hydrosystem. Despite several studies resulting from the proposed navigation project known as the Hidrovía Paraguay-Paraná, little is known about the physical structure of their aquatic environments and its biota. The main purpose of this work is the knowledge of the primary factors which form the structure of the physical habitats in this fluvial segment. In this way, the hydrological and hydraulic regime, channel shape, substrate, hydrological connectivity and the floodplain ontogeny and its evolution were analyzed. Synthesizing we stressed herein that the dynamics of the river-floodplain morphology dependent on the large-scale longitudinal and lateral hydrological connections, and the type and degree of these connections between lotic and lentic environments drive the changes of this seasonally inundated floodplain and its water bodies. In a second paper in this volume, is presented a classification of the Lower Paraguay physical habitats and their relationships with the main physical factors.

4

Geomorphic structure and land cover of extensively managed floodplains of the Nida River

72%

Zajac T., Korzeniak J., Solarz W., Zajac K., Krol W., Krzysciak-Kosinska R.

Nature Conservation

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2002

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tom 59

91-97

5

Model for hydraulic calculations for naturalised channels

72%

Rimkus A., Vaikasas S.

Journal of Water and Land Development

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1999

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nr 03

Naturalisation of channels - water receivers can increase their hydraulic resistance too much. Therefore the hydraulic calculations on such channels are necessary. The existing calculation methods are not sufficiently precise. In this paper the necessary development of these calculations is described.

6

Velocity and discharge prediction in straight compound channels using the eddy viscosity concept

72%

Kubrak J., Tonsmann F.

Journal of Water and Land Development

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2001

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nr 05

The method for predicting the velocity and discharge in compound channels using the eddy viscosity concept by neglecting the secondary flow contribution given by Knight and Shiono is applied to a different set of experimental result. The one-dimensional flow equation was solved using finite differences. Experimental confirmation of these theoretical results is presented for data from smooth and rough channels and a river.

7

Experimental approach to the equation of the regime river and stream

72%

Bartnik W.

Zeszyty Naukowe Akademii Rolniczej we Wrocławiu. Inżynieria Środowiska

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1992

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tom 01

8

Określenie przyczyny zagrożenia powodziowego terenów znajdujących się w strefie oddziaływania stopnia wodnego Łączany

58%

Michalec B.

Acta Scientiarum Polonorum. Formatio Circumiectus

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2012

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tom 11

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nr 4

W pracy przedstawiono opis przebudowy fragmentu systemu hydrotechnicznego Łączany, mającego istotny wpływ na zagrożenie powodziowe miejscowości Zarzecze. Wykonane pomiary geodezyjne i obliczenia hydrauliczne wyznaczonych przekrojów poprzecznych odcinka głównego rowu R tego systemu hydrotechnicznego umożliwiły określenie przyczyny zagrożenia powodziowego terenów miejscowości Zarzecze, znajdujących się w strefie oddziaływania stopnia wodnego Łączany. Stwierdzono zmniejszenie przepustowości badanego odcinka rowu R, tj. od km 4+050 do km 4+113, z wartości 3,19 m3 ∙ s–1, podanej w Projekcie melioracji… [1957], do wartości 1,06 m3 ∙ s–1. Niższa przepustowość spowodowana została zmniejszeniem powierzchni przekroju i zmniejszeniem spadku dna, w wyniku przebudowy tej części rowu w trakcie wykonawstwa przejazdu z przepustem. Przepływy o natężeniu większym od 1,06 m3 ∙ s–1, występując z koryta rowu R, wpływają do kanału ulgi, obciążając pompownię Zarzecze. W przypadku przepływów o większym natężeniu woda gromadzi się w kanale ulgi, a po przekroczeniu jego pojemności następuje zatopienie terenów miejscowości Zarzecze.

9

Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik

Urban flash flood in Gdansk, 2001

58%

Majewski W.

Annals of Warsaw University of Life Sciences - SGGW. Land Reclamation

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2008

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tom 39

Floods in urban areas cause considerable economic losses and affect many people. Measures for flood mitigation in urban areas are primarily of an engineering character, however, existing city infrastructure very often restricts the introduction of appropriate new constructions. The city of Gdańsk is situated at the mouth of the Vistula river, on the area, which forms Vistula delta. It is the most flood-prone agglomeration in Poland. Now there are three possible flood sources. The first is from the moraine hills, in case of intensive precipitation. This area was recently rapidly urbanized. The second source of fl ood is from the Gulf of Gdańsk caused by storm surges and the third is from main channel of Vistula river in case of very high discharge or ice jam. The city of Gdańsk is situated within a complicated system of rivers and channels called Gdańsk Water Node (GWN). It is influenced by the discharge of rivers flowing from the moraine hills in the west, and from possible storm surges in the Gulf of Gdańsk. In July 2001 a severe flash flood, arising for the fi rst time from the moraine hills, caused by very intensive rainfall, hit Gdańsk. In the paper description of the operation of GWN, the flood cause, run and damages are presented. Description of measures, which were proposed to mitigate infl uence of a similar flood in the future are given. These measures were proposed on the basis of detailed field measurements, hydrologic analysis, hydraulic calculations and possible hydro-engineering developments.

10

Transport through pores in PETP membranes - a model for biological systems?

58%

Bashford C. L.

Cellular and Molecular Biology Letters

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1996

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tom 01

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nr 3

Movement of ions, water and non-electrolytes has been measured through narrow pores etched in polyethyleneterephthalate (PETP) membranes previously ‘tracked’ by bombardment with heavy ions. Pore size estimated from flow of water, ions and non-electrolytes is in reasonable agreement with that obtained by a polymer exclusion assay. Flow of ions through narrow pores exhibits characteristic features: i) rapid switching between high- and low- conducting states; ii) selectivity between different ions; iii) inhibition by protons or divalent cations with order of efficacy H+>Zn2+>Ca2+>Mg2+. Ion current and selectivity are reduced when the carboxyl groups lining the pore are methylated. The characteristic features of ion flow in narrow pores arise from the nature of the flow of ions close to a surface bearing fixed charges of the opposite sign.

11

Voltage activated ion channels formed by a synthetic alpha-helical peptide: - Determination of channel stoichiometry and molecular modelling of peptide conformation

58%

Mellor I. R., Kerr I. D., Sansom M. S. P., Sukumar M., Balaram P.

Cellular and Molecular Biology Letters

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1996

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tom 01

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nr 3

We designed and synthesized an 18 residue peptide (MS 18) similar to the channel forming fungal antibiotic alamethicin. MS18 formed ion channels in lipid bilayers exhibiting a low discrete conductance level of 55 pS and brief openings to many other conductance levels. Channel formation was markedly dependent on transbilayer voltage with macroscopic conductance increasing exponentially beyond an activation voltage. The activation voltage was higher for lower concentrations of peptide. The relationship between conductance, voltage and peptide concentration was used to calculate the mean number of peptide monomers forming the MS18 channel. This gave an estimate of 4 MS18 monomers per channel. Molecular modeling of MS18 revealed a predominantly α-helical structure.

12

Growth and population structure of the mussel Anodonta woodiana [Lea, 1834] [Bivalvia, Unionidae] in the heated Konin Lakes System

58%

Afanasjev S. A., Zdanowski B., Kraszewski A.

Archives of Polish Fisheries

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2001

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tom 09

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nr 1

The individual growth rate of the Chinese mussel population of the genus Anodonta which inhabits the warm channels of the heated Konin lakes system was analysed. Four size and age groups were distinguished. The allometric growth of shells during early developmental stages and the isometric growth of 6 - 21 cm shells were ascertained. Three to five years old individuals were typical of the Anodonta woodiana found in the Konin channels. The theoretical maximal life span of the mussels is 10 years, while the maximal shell length is 21 cm.

13

Ecological niche of Dreissena polymorpha [Pall.] aggregations in the heated Konin Lakes System

58%

Sinicyna O. O., Protasov A. A., Zdanowski B., Kraszewski A.

Archives of Polish Fisheries

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2001

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tom 09

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nr 1

The zebra mussel, Dreissena polymorpha (Pall.) inhabits various live and dead substrates of the lotic and lentic zones of the heated Konin lakes. Occurring at depths from 20 cm to 3.5 m, this species showed a preference for Unionidae mussels as a substrate. Aggregations of D. polymorpha varied in number from 2 000 to 2 million individuals per m², while the biomass reached more than 12 kg m⁻² . The most numerous were one year old mussels 5 mm in length, which comprised from 60 - 80% of the population. In the preliminary cooling reservoir, newly settled post-veligers comprised as much as 94% of the total of D. polymorpha numbers. The largest mussels did not exceed 35 mm. Aggregations of D. polymorpha contained 49 invertebrate taxa, and the most frequently occurring subdominants were from the Corophidae and Gammaridae families. The diel destruction of organic matter in the aggregations varied between 20 and 370 kJ m⁻² , depending on the number of animals and their biomass. The turnover coefficient (R/B) in the heated zones was 1.5 times higher, on average, than in the non-heated parts of the system.

14

Episodic channels and the development of dry valleys in cropland

58%

Teisseyre A. K.

Quaestiones Geographicae

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1991-1992

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tom 17-18

15

Estuaries of the Polish Baltic coastal zone

44%

Paturej E.

Baltic Coastal Zone. Journal of Ecology and Protection of the Coastline

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2006

|

tom 10

Estuaries are dynamic ecosystems characterized by great and constant variability of physicochemical gradients and biological parameters. Considerable fluctuations in salinity levels, temperature, pH, concentrations of oxygen, nutrients and organic matter are quite natural in such water bodies. There are many estuarine forms at the Polish Baltic Coast, including open-sea gulfs (the Gulf of Gdansk and the Pomeranian Gulf), water bodies connected to the Baltic Sea (Lake Łebsko) and periodically closed water bodies connected to the Baltic Sea by channels or through river-mouths (Lake Jamno and Lake Gardno). The mouths of large rivers, like Odra and Vistula, also show features of estuaries. Estuaries perform a very important function of specific natural filters for a variety of chemical compounds contained in waters flowing through this area. In this way they form an effective buffer zone that prevents the penetration of toxic biological substances into seawater.

Ograniczanie wyników

Recent developments in studies of sediment transport in open channels

Flow of hydraulic mixtures and energy losses in channels of hydraulic transport systems

Channel-floodplain geomorphology and connectivity of the Lower Paraguay hydrosystem

Geomorphic structure and land cover of extensively managed floodplains of the Nida River

Model for hydraulic calculations for naturalised channels

Velocity and discharge prediction in straight compound channels using the eddy viscosity concept

Experimental approach to the equation of the regime river and stream

Określenie przyczyny zagrożenia powodziowego terenów znajdujących się w strefie oddziaływania stopnia wodnego Łączany

Urban flash flood in Gdansk, 2001

Transport through pores in PETP membranes - a model for biological systems?

Voltage activated ion channels formed by a synthetic alpha-helical peptide: - Determination of channel stoichiometry and molecular modelling of peptide conformation

Growth and population structure of the mussel Anodonta woodiana [Lea, 1834] [Bivalvia, Unionidae] in the heated Konin Lakes System

Ecological niche of Dreissena polymorpha [Pall.] aggregations in the heated Konin Lakes System

Episodic channels and the development of dry valleys in cropland

Estuaries of the Polish Baltic coastal zone