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Wyświetlanie 1-7 z 7
Tytuł:
The dependence between bacterial production and environmental conditions in the Gulf of Gdańsk
Autorzy:
Ameryk, A.
Podgorska, B.
Witek, Z.
Powiązania:
https://bibliotekanauki.pl/articles/48815.pdf
Data publikacji:
2005
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
primary production
Baltic Sea
Gdansk Gulf
environment condition
bacterial production
heterotrophic bacteria
Opis:
Bacterial production, primary production and a number of other environmental factors were measured during six cruises in the Gulf of Gdańsk conducted in various seasons from 1995 to 2001. Bacterial production (BP) in the epipelagic layer ranged from 1.5% (April) to 80% (July) of the gross primary production (PP). Significant differences were observed between the BP/PP ratios in estuarine and open-water areas. The highest values were recorded in the coastal area and near the mouth of the river Vistula. It suggests that allochthonous organic matter has a great influence on BP. The correlations between particular parameters and regression analyses indicated that BP in the Gulf of Gdańsk depended on temperature, organic nitrogen concentration, PP, chlorophyll a concentration, organic phosphorus concentration, salinity and biochemical oxygen demand. Of all the independent variables, the temperature had the greatest impact on BP (R2 = 0.62). There was an inverse parabolic relationship between bacterial production and temperature. It appears that above a temperature of 12◦C bacterial production depended on substrates to a higher degree than on temperature. The negative correlation between BP and concentrations of mineral nitrogen and phosphorus in the annual cycle were probably due to an indirect dependence. A multiple regression equation, which included temperature and organic phosphorus concentrations, explained 78% of the variation in BP. Increasing BP resulted in an increasing biomass of bacterivorous nanoflagellates and of bacterivorous ciliates, which is indicative of bottom-up control in this segment of the trophic chain.
Źródło:
Oceanologia; 2005, 47, 1
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of primary production and pelagic community respiration rates in the coastal zone of the Gulf of Gdańsk
Autorzy:
York, J.K.
Witek, Z.
Labudda, S.
Ochocki, S.
Powiązania:
https://bibliotekanauki.pl/articles/48283.pdf
Data publikacji:
2001
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
oxygen
Baltic Sea
coastal water
Gdansk Gulf
organic matter
community respiration
primary production
coastal zone
Opis:
The organic matter production/respiration balance in the coastal water column was examined, both the primary production and community respiration being measured with the oxygen light-and-dark bottle method. Community respiration (CR) was always lower than the gross primary production (GPP) measured at a standard light intensity of 390 μE m−2 s−1, which amounted, on average, to 30% of GPP. During most of the in situ sampling period, the coastal system (6–7 m depth) was found to be autotrophic, with depth-integrated GPP ranging from 6.7 mmoles O2 m−2 d−1 in December to 214.2 mmoles O2 m−2 d−1 in August, and CR ranging correspondingly from 6.0 to 177.7 mmoles O2 m−2 d−1. However, on some occasions heterotrophic conditions were recorded: depth-integrated GPP
Źródło:
Oceanologia; 2001, 43, 3; 365-370
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Calculation of the photosynthetic quotient (pq) in the Gulf of Gdansk (southern Baltic)
Obliczenia współczynnika fotosyntetycznego (pq) dla Zatoki Gdańskiej (Bałtyk Południowy)
Autorzy:
Wielgat-Rychert, M.
Rychert, K.
Witek, Z.
Zalewski, M.
Powiązania:
https://bibliotekanauki.pl/articles/84859.pdf
Data publikacji:
2017
Wydawca:
Akademia Pomorska w Słupsku
Tematy:
calculation
photosynthetic quotient
Gdansk Gulf
Baltic Sea
Opis:
The photosynthetic quotient (PQ) is defined as the molar ratio of oxygen released to the carbon dioxide assimilated during photosynthesis. Calculation of correct PQ values of natural phytoplankton populations is crucial for understanding of carbon budgets but often result in values that differ highly from the expected stoichiometric proportions of photosynthetic products. In the present study, measurements of primary production, that is, CO2 assimilation, performed with the standard isotopic method (14C) and oxygen release estimated during photosynthesis with the light-and-dark bottle method were compared to calculate PQ in the southern Baltic (Gulf of Gdańsk, Poland). The PQ average was 1.28 (ANOVA; F = 872; R2 = 0.92; n = 77; p < 0.001). Neither nitrogen source nor phytoplankton composition was noted to impact PQ values. Very high PQ values in the lower range of production rates (that cannot be explained by the stoichiometric proportion of photosynthesis products) were interpreted as artifacts related to the lower sensitivity of the oxygen method compared to that of the 14C method.
Współczynnik fotosyntetyczny (PQ) definiowany jest jako molowy stosunek uwolnionego tlenu do węgla związanego w procesie fotosyntezy. Obliczenie poprawnej wartości PQ dla populacji fitoplanktonu występujących w środowisku jest zasadnicze dla sporządzenia poprawnego bilansu węgla, ale często obliczone z pomiarów wartości PQ różnią się znacznie od proporcji stechiometrycznych tlenu i węgla w produktach fotosyntezy. W niniejszej pracy przeprowadzono pomiary asymilacji węgla, czyli produkcji pierwotnej, przy użyciu standardowej metody izotopowej (z izotopem węgla 14C) oraz pomiary uwolnionego tlenu za pomocą metody jasnych i ciemnych butelek i na tej podstawie obliczono współczynnik fotosyntetyczny dla Bałtyku południowego (Zatoka Gdańska, Polska). Obliczona średnia wartość PQ wynosiła 1,28 (ANOVA; F = 872; R2 = 0,92; n = 77; p < 0,001). Nie odnotowano, aby wartości PQ zależały od rodzaju azotu wykorzystanego w procesie asymilacji (azot azotanowy czy amonowy) lub od składu fitoplanktonu. Bardzo wysokie wartości PQ obliczone w zakresie niskich wartości produkcji pierwotnej (wartości, które nie zgadzają się zupełnie z proporcjami stechiometrycznymi produktów fotosyntezy) zostały zinterpretowane jako artefakty wynikające z metodyki pomiarowej, ponieważ metoda tlenowa ma znacznie mniejszą czułość niż metoda izotopowa.
Źródło:
Baltic Coastal Zone. Journal of Ecology and Protection of the Coastline; 2017, 21
1643-0115
Pojawia się w:
Baltic Coastal Zone. Journal of Ecology and Protection of the Coastline
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Basic for a valuation of the Polish Exclusive Economic Zone of the Baltic Sea: Rationale and quest for tools
Autorzy:
Weslawski, J.M.
Andrulewicz, E.
Kotwicki, L.
Kuzebski, E.
Lewandowski, A.
Linkowski, T.
Massel, S.R.
Musielak, S.
Olanczuk-Neyman, K.
Pempkowiak, J.
Piekarek-Jankowska, H.
Radziejewska, T.
Rozynski, G.
Sagan, I.
Skora, K.E.
Szefler, K.
Urbanski, J.
Witek, Z.
Wolowicz, M.
Zachowicz, J.
Zarzycki, T.
Powiązania:
https://bibliotekanauki.pl/articles/47570.pdf
Data publikacji:
2006
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
marine environment
erosion
mineral resource
biofiltration
Polish Exclusive Economic Zone
economic valuation
Baltic Sea
ecosystem
marine ecosystem
coastal sand
fish resource
Opis:
This paper summarises current knowledge of goods and services in the Polish Exclusive Economic Zone of the Baltic Sea ecosystem. It reviews specific properties of the Baltic that could be used for economic valuation. Goods and services range from the familiar resources of fish and minerals, which were valued with the Productivity Method, to less obvious services provided by the ecosystem such as biofiltration in coastal sands, valued with either the Replacement Cost or Damage Cost Avoided methods. Disservices to the marine ecosystem are also considered, e.g. erosion and coastal flooding, including the costs of planned mitigating measures. This paper emphasises the importance of using valuation methods to help make better-educated decisions for the sustainability of the Baltic Sea.
Źródło:
Oceanologia; 2006, 48, 1
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Fully Computerized Scanning Tunnelling Microscope
Autorzy:
Chwiałkowski, M.
Klusek, Z.
Kobierski, P.
Olejniczak, W.
Sławski, M.
Witek, A.
Powiązania:
https://bibliotekanauki.pl/articles/1929317.pdf
Data publikacji:
1993-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
07.80.+x
Opis:
A new, fully computerized and inexpensive, scanning tunnelling microscope was designed and built. Its key design feature is the application of the high sensitivity bimorph, for the coarse positioning of the bimorph is > 0.03 mm and can be divided up to the 12 bit number of steps. The bimorph positioning implies that this microscope is fully computer controlled, and using of bimorph instead of inch-worm implies low cost of the unit. The microscope can create images of the surface in the constant current mode and in the imaging current mode. The presented microscope works with the z-axis analog or digital feedback loop optionally. All parameters of the analog and digital feedback loop are computer controlled. Due to the digital z-axis feedback loop benefits, electron tunneling spectroscopy mode is naturally accessible. The performance of the microscope was tested in air by imaging of surface of HOPG (high oriented pyrolytic graphite).
Źródło:
Acta Physica Polonica A; 1993, 83, 5; 621-628
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ceramic-Carbon Filters for Molten Metal Alloys Filtration
Autorzy:
Asłanowicz, M.
Ościłowski, A.
Lipowska, B.
Witek, J.
Robak, Z.
Muzyka, R.
Kowalski, P.
Wańczyk, K.
Powiązania:
https://bibliotekanauki.pl/articles/381136.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
innovative foundry technologies
innovative materials
molten metals
filtration
foam filter
technological line
innowacyjne technologie odlewnicze
innowacyjne materiały
topnienie metali
filtracja
filtr piankowy
linia technologiczna
Opis:
In 2014 we finished research works involved in the development of a technology for manufacturing innovative ceramic-carbon foam filters for molten metal alloys filtration, which were financed by the National Centre for Research and Development (NCBiR) from INNOTECH programme resources. A batch of the filters produced in this technology was tested in practice in domestic cast steel and cast iron foundries. The trials were successful and foundries declared their intention to purchase the newly-developed filters for the current production of casts. This provided an incentive for “Ferro-Term” Sp. z o.o. to start design works on the prototype line for a serial production of these filters. At the same time, in co-operation with a scientific consortium, including the co-authors of the technology, i.e. the Institute of Ceramics and Building Materials, Refractory Materials Division in Gliwice, Institute for the Chemical Processing of Coal in Zabrze and Foundry Research Institute in Cracow, the company made a successful attempt to raise some funds for the necessary adaptation of the developed technology from the semi-technical to industrial scale from Intelligent Development Operational Programme. In the article we have presented information on the effects of works performed within the framework of the project entitled “Modernization and adaptation of the existing technological line for purposes related to technology verification and start-up of the production of innovative ceramic-carbon filters for molten metal alloy filtration”.
Źródło:
Archives of Foundry Engineering; 2019, 1; 98-102
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The CC1 project – system for Private Cloud Computing
Autorzy:
Chwastowski, J.
Grzymkowski, R.
Kruk, M.
Nabożny, M.
Natkaniec, Z.
Olszewski, A.
Pałka, H.
Sobocińska, Z.
Sośnicki, T.
Szostak, M.
Syktus, P.
Wójcik, P.
Wojtoń, T.
Zdybał, M.
Żabiński, B.
Witek, M.
Powiązania:
https://bibliotekanauki.pl/articles/305307.pdf
Data publikacji:
2012
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
virtual machine
cloud computing
private cloud
distributed computing system
Opis:
The main features of the Cloud Computing system developed at IFJ PAN are described. The project is financed from the structural resources provided by the European Commission and the Polish Ministry of Science and Higher Education (Innovative Economy, National Cohesion Strategy). The system delivers a solution for carrying out computer calculations on a Private Cloud computing infrastructure. It consists of an intuitive Web based user interface, a module for the users and resources administration and the standard EC2 interface implementation. Thanks to the distributed character of the system it allows for the integration of a geographically distant federation of computer clusters within a uniform user environment.
Źródło:
Computer Science; 2012, 13 (2); 103-111
1508-2806
2300-7036
Pojawia się w:
Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-7 z 7

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