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Tytuł:
Tradycje i zakres polskich badań polarnych na przykładzie działalności Polskiej Stacji Polarnej na Spitsbergenie
Autorzy:
Dolnicki, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/471661.pdf
Data publikacji:
2018
Wydawca:
Uniwersytet Pedagogiczny im. Komisji Edukacji Narodowej w Krakowie
Tematy:
Arctic
Spitsbergen
polar station
polar research
Arktyka
stacja polarna
badania polarne
Opis:
In the paper there is presented historical outline of Polish research conducted in polar regions. An important aspect of the work is showing of contemporary involvement of Polish scientific centres in polar research indicating present state and plans for future. In the paper there is also presented functioning of polar station exemplified on the Stanisław Siedlecki Polish Polar Station in Spitsbergen. Presented material is a set of information which may be used by the teachers realizing programme content, which contemporary introduce problems of involvement of Poland in polar research to the primary schools.
W artykule przedstawiono rys historyczny polskich badań naukowych prowadzonych na obszarach polarnych. Ważnym aspektem pracy jest przedstawienie współczesnego zaangażowania polskich ośrodków naukowych w badania polarne, wskazanie na ich stan aktualny oraz na plany dotyczące przyszłości. W pracy przedstawiono również sposób funkcjonowania stacji polarnej na przykładzie Polskiej Stacji im. Stanisława Siedleckiego na Spitsbergenie. Prezentowany materiał jest zbiorem informacji możliwych do wykorzystania przez nauczycieli realizujących obowiązującą podstawę programową, która wprowadza do szkół podstawowych zagadnienia dotyczące zaangażowania Polski w badania polarne.
Źródło:
Annales Universitatis Paedagogicae Cracoviensis Studia Geographica; 2018, 12
2084-5456
Pojawia się w:
Annales Universitatis Paedagogicae Cracoviensis Studia Geographica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Geomorphological settings of Polish research areas on Spitsbergen
Autorzy:
Zwoliński, Z.
Giżejewski, J.
Karczewski, A.
Kasprzak, M.
Lankauf, K. R.
Migoń, P.
Pękala, K.
Repelewska-Pękalowa, J.
Rachlewicz, G.
Sobota, I.
Stankowski, W.
Zagórski, P.
Powiązania:
https://bibliotekanauki.pl/articles/295146.pdf
Data publikacji:
2013
Wydawca:
Stowarzyszenie Geomorfologów Polskich
Tematy:
polar landform
polar geomorphology
glacial relief
postgalacial relief
Polish geomorphological research
Spitsbergen
Opis:
Paper described geomorphological characteristics of landform sets which occur on research areas investigated by Polish geomorphologists on Spitsbergen. These area involve four areas along the western coast of Spitsbergen, i.e. vicinities of the Kaffiøyra, the Werenskioldbreen, the Calypsostranda, and the Hornsund, as wel as one area located in the central part of Spitsbergen, i.e. vicinity of Billefjord with special emphasis on surroundings of the Petuniabkukta. Landforms are characterized in different morphogenetic terms, mainly glacial, peryglacial, deundational, slope, fluvial, even eolian factors and processes.
Źródło:
Landform Analysis; 2013, 22; 125-143
1429-799X
Pojawia się w:
Landform Analysis
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Polar research in public discourse - setting the stage
Autorzy:
Weslawski, J.M.
Powiązania:
https://bibliotekanauki.pl/articles/2079069.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
polar research
scientific research
motivation
inspiration
historical factor
public opinion
polar region
Opis:
Polar Research gained bigger than ever extent and support, both on the state-political and the wide public level. We want to start the discussion on how the public concern is formed, and what are the inspirations that drive researchers to choose this type of career. It seems that in the non-Arctic country like Poland the sentiment, associated with the historical polar events together with widely accessible and attractive documentary films, was essential in shaping the societal support for spending public money on polar studies.
Źródło:
Oceanologia; 2020, 62, 4PB; 634-636
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spatial distribution, host specificity and genetic diversity of Onchobothrium antarcticum in the Southern Ocean
Autorzy:
Gordeev, Ilya I.
Polyakova, Tatyana A.
Volkov, Alexander A.
Powiązania:
https://bibliotekanauki.pl/articles/2041732.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Antarctic
parasite
cestodes
rDNA
polar
Źródło:
Polish Polar Research; 2021, 42, 4; 269-285
0138-0338
2081-8262
Pojawia się w:
Polish Polar Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Polskie badania polarne z zakresu meteorologii i klimatologii
Polish Polar Research in the Field of Meteorology and Climatology
Autorzy:
Przybylak, Rajmund
Araźny, Andrzej
Miętus, Mirosław
Migała, Krzysztof
Niedźwiedź, Tadeusz
Rachlewicz, Grzegorz
Siwek, Krzysztof
Ustrnul, Zbigniew
Powiązania:
https://bibliotekanauki.pl/articles/163905.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwa Geofizyczne
Tematy:
polskie badania polarne
polarne badania meteorologiczne
polarne badania klimatologiczne
Arktyka
Antarktyka
Polish polar research
polar meteorological research
polar climate studies
Arctic
Antarctic
Opis:
W artykule dokonano przeglądu i podsumowania dorobku polskich badań meteorologicznych i klimatologicznych w obydwu obszarach polarnych w ujęciu historycznym. Omówiono różne aspekty tegoż dorobku, poczynając od organizacji i udziału w wyprawach polarnych, prowadzonego w ich trakcie zakresu pomiarów i obserwacji meteorologicznych oraz uzyskanych wyników dotyczących poznania pogody i klimatu badanych obszarów. Scharakteryzowano także dorobek publikacyjny nie będący wynikiem udziału w pomiarach i obserwacjach meteorologicznych w ramach ekspedycji polarnych, lecz efektem innych prac badawczych. Przeprowadzona szczegółowa analiza aktywności polskich naukowców w zakresie meteorologii i klimatologii polarnej w okresie od jej rozpoczęcia (koniec XIX wieku) do chwili obecnej wykazała istnienie czterech wyraźnych okresów (fal) o wyraźnie większym natężeniu tej aktywności: 1) lata 30., 2) 1957-1962, 3) lata 70., szczególnie ich druga połowa, 4) ostatnie trzydzieści lat z maksimum w okresie 2004-2009 (okres przygotowawczy 2004-2007 i IV Międzynarodowy Rok Polarny 2007-2009). Chociaż obszarem badań meteorologicznych i klimatologicznych prowadzonych przez polskich naukowców były obydwa obszary polarne, to jednak zdecydowanie największe osiągnięcia badawcze i publikacyjne (w tym w czasopismach z bazy Journal Citation Reports) dotyczą Svalbardu. Stwierdzono, iż polscy naukowcy wespół z badaczami norweskimi mają największy udział w rozpoznaniu warunków pogodowych i klimatycznych tego obszaru. Przeprowadzona szczegółowa analiza problematyki badawczej pozwoliła skonstatować, iż jest ona bardzo wszechstronna, tym niemniej za polską specjalność w badaniach meteorologicznych i klimatologicznych, szczególnie tych prowadzonych dla Svalbardu uznać należy: 1) badania mikro- a szczególnie topoklimatyczne oraz 2) badania wpływu cyrkulacji atmosferycznej na kształtowanie się pogody i klimatu.
The article presents a synthetic review and summary of the achievements of Polish meteorological and climatological research in both polar areas, with a historical perspective. Various aspects of these achievements are discussed, beginning with the organisation of and participation in polar expeditions, the scope of meteorological measurements and observations conducted during research, and results from weather and climate research in the study areas. Publications that have resulted from research other than meteorological measurements and observations conducted as part of polar expeditions are also described. A detailed analysis of the activity of Polish scientists in the field of polar climatology and meteorology since its inception in the late nineteenth century revealed four distinct periods (waves) of clearly more intense activity: 1) the 1930s, 2) 1957-1962, 3) the 1970s, especially the latter half, 4) the last 30 years, with a peak in 2004-2009 (preparatory period 2004-2007 and IV International Polar Year 2007-2009). Although the meteorological and climatological research conducted by Polish scientists included both polar regions, decidedly the greatest research and publication achievements (including journals from the Journal Citation Reports database) concern Svalbard. It was found that, alongside Norwegian researchers, Polish scientists account for the largest share in the diagnosis of weather and climate conditions in this area. A detailed analysis of the research issues led to the conclusion that Polish meteorological and climatological research is very comprehensive but, nevertheless, its specialisations, especially with regards to studies on Svalbard, are: 1) micro-climatic research, and especially topoclimatic research; and 2) research into the influence of atmospheric circulation in determining weather and climate.
Źródło:
Przegląd Geofizyczny; 2019, 1-2; 3-33
0033-2135
Pojawia się w:
Przegląd Geofizyczny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design and implementation of large vessel navigation system based on beidou cors
Autorzy:
Huang, P.
Liu, Y.
Du, Z.
Chen, Q.
Chen, J.
Powiązania:
https://bibliotekanauki.pl/articles/260264.pdf
Data publikacji:
2017
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
Berthing
ship-based
Polar Coordinates
CORS
Opis:
The ship’s pilot can obtain the ship auxiliary information through the navigation system, when berthing system can display the parameters such as traverse speed and distance of the ship. But most of the system data show that there are insufficient precision. Taking the CORS system to obtain the location information, data Calculation of Berthing System based on Polar Coordinate Algorithm, this paper puts forward a solution to the “dead point” of the berthing and aiding system, which has a certain reference value for the design of the ship berthing assistance system.
Źródło:
Polish Maritime Research; 2017, S 3; 12-15
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Runoff variability in the Scott River (sw Spitsbergen) in summer seasons 2012–2013 in comparison with the period 1986–2009
Autorzy:
Franczak, Łukasz
Kociuba, Waldemar
Gajek, Grzegorz
Powiązania:
https://bibliotekanauki.pl/articles/1052853.pdf
Data publikacji:
2016-09-15
Wydawca:
Uniwersytet im. Adama Mickiewicza w Poznaniu
Tematy:
hydrology
proglacial river
polar region
Svalbard
Opis:
River runoff variability in the Scott River catchment in the summer seasons 2012 and 2013 has been presented in comparison to the multiannual river runoff in 1986–2009. Both in particular seasons and in the analysed multiannual, high variability of discharge rate was recorded. In the research periods 2012–2013, a total of 11 952 water stages and 20 flow rates were measured in the analysed cross-section for the determination of 83 daylong discharges. The mean multiannual discharge of the Scott River amounted to 0.96 m3·s–1. The value corresponds to a specific runoff of 94.6 dm3·s–1·km2, and the runoff layer 937 mm. The maximum values of daily discharge amounted to 5.07 m3·s–1, and the minimum values to 0.002 m3·s–1. The highest runoff occurs in the second and third decade of July, and in the first and second decade of August. The regime of the river is determined by a group of factors, and particularly meteorological conditions affecting the intensity of ablation, and consequently river runoff volume. We found a significant correlation (0.60 in 2012 and 0.67 in 2013) between the air temperature and the Scott River discharge related to the Scott Glacier ice melt.
Źródło:
Quaestiones Geographicae; 2016, 35, 3; 39-50
0137-477X
2081-6383
Pojawia się w:
Quaestiones Geographicae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Notes on the Occurrence of Tintinnid Ciliates, and the Nasselarian Radiolarian Amphimelissa setosa of the Marine Microzooplankton, in the Chukchi Sea (Arctic Ocean) Sampled each August from 2011 to 2020
Autorzy:
Dolan, John R.
Moon, Jong-Kuk
Yang, Eun Jin
Powiązania:
https://bibliotekanauki.pl/articles/2041957.pdf
Data publikacji:
2021-08-05
Wydawca:
Uniwersytet Jagielloński. Wydawnictwo Uniwersytetu Jagiellońskiego
Tematy:
Microzooplankton
plankton
tintinnida
radiolaria
polar seas
Opis:
Here we summarize the results from 10 cruises in the Chukchi Sea, in August, each year from 2011 to 2020. Samples for the qualitative analysis of the microzooplankton were obtained from stations located across the Chukchi Sea using a 20µm plankton net. Conditions encountered, in terms of sea ice coverage and chlorophyll concentrations, varied widely from year to year without any obvious relationship with the composition of the microzooplankton assemblage. Examining a total of 242 samples gathered, we found a total of 44 tintinnid species (morphologically distinct forms). Plotting cumulative number of tintinnid species encountered vs cumulative number of samplings gave a typical species accumulation curve showing no sign of saturation suggesting that continued sampling in the Chukchi Sea will likely yield increases in the tintinnid species catalogue. The tintinnid species found ranged widely in lorica opening diameters (LOD) from about 11 µm to 80 µm in diameter. However, the median size of the LOD of the tintinnid assemblages varied little from year to year ranging only from about 30 µm to 40 µm. Most of the forms encountered were found in samples from only 1 or 2 cruises. Very few forms were found every year throughout the 10 years of sampling. These were 5 species of tintinnids (Acanthostomella norvegica, Leprotintinnus pellucidus, Pytchocylis obtusa, Salpingella acuminata, Salpingella faurei) and the nasselarian radiolarian Amphimelissa setosa. Examples of the morphological variability observed among individuals of Acanthostomella norvegica and Pytchocylis obtusa within single samples are shown with some individuals easily confused with forms described as other species are shown. To our knowledge, our data are the most extensive data set on Chukchi Sea microplankton. We provide all of the data recorded, which may serve as a baseline from which to assess changes projected in Arctic Sea systems, in a supplementary data file.
Źródło:
Acta Protozoologica; 2021, 60; 1-11
1689-0027
Pojawia się w:
Acta Protozoologica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Physical condition and physical fitness of the candidates for polar expeditions
Autorzy:
Kłossowski, Marek
Łysoń-Wojciechowska, Grażyna
Kwarecki, Krzysztof
Powiązania:
https://bibliotekanauki.pl/articles/2057656.pdf
Data publikacji:
1982
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
medical examination
polar expeditions
physical fitness
Źródło:
Polish Polar Research; 1982, 3, 1-2; 89-94
0138-0338
2081-8262
Pojawia się w:
Polish Polar Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Neoichnology of an Arctic fluvial point bar, North Slope, Alaska (USA)
Autorzy:
Martin, A. J.
Powiązania:
https://bibliotekanauki.pl/articles/2059252.pdf
Data publikacji:
2009
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
ichnofacies
polar
Scoyenia
Mermia
trace fossils
Opis:
This study is the first to describe the neoichnology of an Arctic fluvial point bar (Colville River, Alaska, USA) and examine the sedimentological effects of tracemakers in this sedimentary setting. Seasonal extremes in discharge and sediment deposition in this system result in sandwaves, current ripples, gravel bars and mud veneers, with the latter forming extensive mudcracks. Organismal traces are abundantly represented in sandy mudflats on the downstream portion of the point bar and are characterized by: (1) abundant shallow horizontal invertebrate burrows and surface trails, directly comparable to Treptichnus, Cochlichnus and Aulichnites; (2) avian tracks and (3) large mammal tracks. Treptichnus-like burrows are attributed to dipteran larvae tracemakers, whereas Cochlichnus- and Helminthoidichnites-like trails were likely from nematodes or oligochaetes. Avian tracks are primarily from seagulls, geese, swans and plovers; mudcracks were connected directly to tracks, which developed as a result of in creased amounts of sunlight available during the polar summer. Mam mal tracks were dom i nated by those of caribou (Rangifer tarandus), but include grizzly bear (Ursos arctos) and other mammals. Caribou herds significantly impacted emergent and submergent mudflat surfaces through advection of saturated thixotropic muds and dry sand, while also fracturing mudcracked zones, and hence actively produced mud clasts. Vertebrates thus can cause considerable mixing, redistribution and erosion of sediments in Arctic point bars with only a few months of activity. Ichnodiversity was low but accompanied by high trace abundance, reflecting fa vorable hydrodynamic, solar and atmospheric conditions throughout a polar summer. In contrast, sedimentation and bioturbation are absent during winter months, when ice cover prevents organismal interactions with fluvial sediments. As a reult, the ichnocoenose does not fit easily into paradigms of previously defined continental ichnofacies (e.g., Mermia and Scoyenia) and is more like a composite ichnofacies. These findings can thus serve as a starting point for more detailed studies of circum polar point bars, while also adding new perspectives to the interpretation of trace fossils in circum polar fluvial environments.
Źródło:
Geological Quarterly; 2009, 53, 4; 383-396
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Аналіз технологічної схеми визначення кількісних параметрів острівних льодовиків за результатами цифрового стереофотограмметричного энймання
Analyses of technological scheme of determination of quantative parameters of island glaciers using results of digital stereophotogrammetric surieying
Autorzy:
Dorozhynskyy, O.
Glotov, V.
Powiązania:
https://bibliotekanauki.pl/articles/129611.pdf
Data publikacji:
2004
Wydawca:
Stowarzyszenie Geodetów Polskich
Tematy:
lodowiec
stacja polarna
glacier
polar station
Opis:
Analyses of digital phototheodolite method o f researches of island glaciers in region of Ukrainian antarctic station of Vernadskyy is pesented in the paper. Apriory calculation of accuracy of determination of surface values of glaciers is shown. The conclusions about accuracy increasing of the method o f vertical network are made on its example. Results o f researches arc given.
Źródło:
Archiwum Fotogrametrii, Kartografii i Teledetekcji; 2004, 15; 35-39
2083-2214
2391-9477
Pojawia się w:
Archiwum Fotogrametrii, Kartografii i Teledetekcji
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Process monitoring in end milling using polar figures
Autorzy:
Goetz, Sven
Schraknepper, Daniel
Faustini, Gabriel
Bergs, Thomas
Powiązania:
https://bibliotekanauki.pl/articles/100129.pdf
Data publikacji:
2020
Wydawca:
Wrocławska Rada Federacji Stowarzyszeń Naukowo-Technicznych
Tematy:
process monitoring
tool wear
polar figur
Opis:
Knowledge of the tool wear state in machining has become an important issue in research and industrial application. Current systems use the spindle power or cutting force as measured variable and refer it to a taught set point. However, this method lacks the ability to adapt to new work piece geometries. A new approach focusses on the tool instead of the work piece, and uses a sensory tool holder with integrated strain gauges. This tool holder provides polar figures whose shapes relate to the engagement conditions and whose area is a function of the tool load. As the tool load increases with tool wear, the area of the polar figures provides information about the tool wear status, and with knowledge about the engagement conditions, the model can be calibrated.
Źródło:
Journal of Machine Engineering; 2020, 20, 3; 95-105
1895-7595
2391-8071
Pojawia się w:
Journal of Machine Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
So, What is Actually the Distance from the Equator to the Pole? – Overview of the Meridian Distance Approximations
Autorzy:
Weintrit, A.
Powiązania:
https://bibliotekanauki.pl/articles/116295.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
Polar Distance
Geodetic Aspects
Meridian Distance
Opis:
In the paper the author presents overview of the meridian distance approximations. He would like to find the answer for the question what is actually the distance from the equator to the pole ‐the polar distance. In spite of appearances this is not such a simple question. The problem of determining the polar distance is a great opportunity to demonstrate the multitude of possible solutions in common use. At the beginning of the paper the author discusses some approximations and a few exact expressions (infinite sums) to calculate perimeter and quadrant of an ellipse, he presents convenient measurement units of the distance on the surface of the Earth, existing methods for the solution of the great circle and great elliptic sailing, and in the end he analyses and compares geodetic formulas for the meridian arc length.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2013, 7, 2; 259-272
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Changes in content of polar and non-polar lipids in plants with different chilling sensitivity
Autorzy:
Wojtowicz, J.
Gieczewska, K.
Garstka, M.
Powiązania:
https://bibliotekanauki.pl/articles/80143.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
conference
polar lipid
non-polar lipid
content change
chilling stress
necrotic spot
chloroplast
plant cell
thylakoid membrane
Źródło:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2013, 94, 3
0860-7796
Pojawia się w:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Coccolithophorids in Polar Waters: Calciarcus spp. Revisited
Autorzy:
Thomsen, Helge A.
Østergaard, Jette B.
Powiązania:
https://bibliotekanauki.pl/articles/763503.pdf
Data publikacji:
2014
Wydawca:
Uniwersytet Jagielloński. Wydawnictwo Uniwersytetu Jagiellońskiego
Tematy:
Coccolithophorid, holococcolith, Calciarcus, polar regions, electron microscopy
Opis:
The genus Calciarcus is revisited here with the purpose of providing, based on additional sampling from both polar regions, an update on species diversity and morphology that can serve as a reference for future work. The geographic realm of the genus is significantly widened and a case is built based on consistency in appearance in favour of adding Calciarcus spp. to the well-defined community of bipolar weakly calcified coccolithophorid genera. Despite the multitude of specimens available for analysis and the fact that the specimens examined distribute themselves within three clusters based on morphological features of coccolith superstructures, it has not been possible at this stage to define a robust framework for differentiation among species of Calciarcus. Circumstantial evidence exist linking species of Wigwamma with species of Calciarcus in haploid-diploid life cycles.
Źródło:
Acta Protozoologica; 2014, 53, 2
1689-0027
Pojawia się w:
Acta Protozoologica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Krakowskie polarne badania meteorologiczne i klimatologiczne
Krakow polar meteorological and climatological research
Autorzy:
Ustrnul, Z.
Powiązania:
https://bibliotekanauki.pl/articles/260838.pdf
Data publikacji:
2015
Wydawca:
Stowarzyszenie Klimatologów Polskich
Tematy:
badania polarne
meteorologia i klimatologia
Arktyka
Spitsbergen
Ural Północny
polar research
meteorology and climatology
Arctic
Polar Urals
Opis:
W opracowaniu przedstawiono najważniejsze informacje o badaniach meteorologicznych i klimatycznych prowadzonych w obszarach polarnych przez pracowników Uniwersytetu Jagiellońskiego. Po omówieniu krótkiej historii badań polarnych i udziale w nich poszczególnych osób związanych z ośrodkiem krakowskim przedstawiono przegląd najważniejszych problemów podejmowanych w czasie tych badań. Dotyczyły one różnych szczegółowych zagadnień obejmujących przede wszystkim Spitsbergen.
The study describes general information about meteorological and climatological research conducted in polar regions by the Jagiellonian University staff members as well as people from other institutions from Krakow. The short history of the polar studies and the scientific contribution of particular people is followed by the survey of main research domains, topics and problems investigated during the expeditions. They concerned detailed issues connected mainly with Spitsbergen.
Źródło:
Problemy Klimatologii Polarnej; 2015, 25; 67-74
1234-0715
Pojawia się w:
Problemy Klimatologii Polarnej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Low energy electrons in non-polar liquids
Autorzy:
Schmidt, W.
Illenberger, E.
Powiązania:
https://bibliotekanauki.pl/articles/148513.pdf
Data publikacji:
2003
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
electrons
energetics
kinetics
non-polar liquids
lifetime
Opis:
The properties of excess electrons in non-polar liquids have been studied for more than 30 years. Here, pertinent results are reviewed and discussed with respect to the possibility of studying electron-molecule interactions with low energy electrons in the liquid phase. Some new results on the estimate of the electron lifetime in the delocalized state in liquid hydrogen are presented.
Źródło:
Nukleonika; 2003, 48, 2; 75-82
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Coccolithophorids in Polar Waters: Trigonaspis spp. Revisited
Autorzy:
Thomsen, Helge A.
Powiązania:
https://bibliotekanauki.pl/articles/763758.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Jagielloński. Wydawnictwo Uniwersytetu Jagiellońskiego
Tematy:
Coccolithophorid, holococcolith, Trigonaspis, polar regions, electron microscopy
Opis:
A group of weakly calcified coccolithophorid genera and species were described from polar regions several decades ago. In the interim period a few additional findings have been reported adding to the morphological and biogeographical databases of some of the species. The holococcolithophorid genus Trigonaspis is revisited here with the purpose of providing, based on additional sampling from both polar regions, an update on species morphology, life history aspects and biogeography. The genus Trigonaspis as currently circumscribed comprises four taxa – two from each polar region. The triangular plates of crystallites that cover the surfaces of both the tower-shaped flagellar pole coccoliths and the disc-shaped body coccoliths are the keystone features of the genus. Circumstantial evidence exists linking species of Trigonaspis with species of Pappomonas in haploid-diploid life cycles.
Źródło:
Acta Protozoologica; 2015, 54, 2
1689-0027
Pojawia się w:
Acta Protozoologica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Polarne badania meteorologiczne i klimatyczne Uniwersytetu Śląskiego
Polar investigations of the University of Silesia in Katowice in meteorology and climatology
Autorzy:
Niedźwiedź, T.
Powiązania:
https://bibliotekanauki.pl/articles/260705.pdf
Data publikacji:
2015
Wydawca:
Stowarzyszenie Klimatologów Polskich
Tematy:
meteorologia polarna
klimatologia polarna
Arktyka
Spitsbergen
Uniwersytet Śląski
polar meteorology
polar climatology
Arctic
University of Silesia in Katowice
Opis:
Opracowanie zawiera najważniejsze informacje o badaniach meteorologicznych i klimatologicznych obszarów polarnych wykonanych przez pracowników Wydziału Nauk o Ziemi Uniwersytetu Śląskiego. Badania te koncentrowały się głównie na Spitsbergenie w Arktyce. Po przedstawieniu krótkiej historii badań polarnych przedstawiono przegląd najważniejszych problemów jakie podejmowano w latach 1977-2015 w ramach omawianych nauk. Do najważniejszych należą publikacje z zakresu klimatologii synoptycznej dotyczące roli cyrkulacji atmosfery w kształtowaniu klimatu Arktyki bazujących na oryginalnym kalendarzu typów i wskaźników cyrkulacji dla Spitsbergenu. Dwie osoby uczestniczyły w opracowaniu obszernej monografii klimatycznej Polskiej Stacji Polarnej w Hornsundzie na Spitsbergenie, opublikowanej pod redakcją Andrzeja A. Marsza i Anny Styszyńskiej zarówno w języku polskim w roku 2007 oraz w języku angielskim w roku 2013. Artykuł zawiera też obszerną bibliografię prac z zakresu meteorologii i klimatologii polarnej opublikowanych przez pracowników naukowych Uniwersytetu Śląskiego.
The paper contains information on the most significant meteorological and climatological research conducted in the Polar Regions by the staff of the University of Silesia in Katowice. The research was mainly carried out on Spitsbergen in the Arctic. A brief survey of polar research history is followed by the review of the most significant research topics studied in 1977-2015 period within the fields under consideration. The most significant papers cover the field of synoptic climatology. They discuss the role of atmospheric circulation in shaping the climate of the Arctic on the base of original calendar of circulation types and circulation indices for Spitsbergen. Two scientists contributed to the comprehensive climatic monography of Polish Polar Station in Hornsund on Spitsbergen. The monography was edited by Andrzej A. Marsz and Anna Styszyńska both in Polish and English and published in 2007 and 2013 respectively. The article includes also bibliography of works connected with polar meteorology and climatology published by the scientist of the University of Silesia in Katowice.
Źródło:
Problemy Klimatologii Polarnej; 2015, 25; 33-48
1234-0715
Pojawia się w:
Problemy Klimatologii Polarnej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Laserowe urządzenie grawerujące szkło z biegunowym aparatem ruchowym
Device for laser engraving glass with polar positioning system
Autorzy:
Trochimczuk, R.
Powiązania:
https://bibliotekanauki.pl/articles/386889.pdf
Data publikacji:
2008
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
laser
grawerowanie
biegunowy aparat ruchowy
engraving
polar positioning
Opis:
W pracy przedstawiono analizę aparatu ruchowego pozycjonera laserowego urządzenia do grawerowania szkła lub innych przezroczystych dielektryków. Zaprezentowano koncepcję budowy biegunowego aparatu ruchowego pozycjonera. Przedstawiono scenariusze przemieszczeń ramienia obróbczego oraz obiektu obrabianego w zakładanej koncepcji.
There is presented the analysis of polar positioning system of laser device for glass engraving in the work. The new concept of polar positioning system, alternative for the Cartesian one, is presented too. The scripts of dislocations working arm and forming object in founded conception of polar positioning system is defined.
Źródło:
Acta Mechanica et Automatica; 2008, 2, 1; 77-80
1898-4088
2300-5319
Pojawia się w:
Acta Mechanica et Automatica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Increase of tourist traffic on Spitsbergen: An environmental challenge or chance for progress in the region?
Autorzy:
Kugiejko, Magdalena
Powiązania:
https://bibliotekanauki.pl/articles/2041747.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Arctic
Svalbard
polar tourism
environmental impact
economic development
Źródło:
Polish Polar Research; 2021, 42, 2; 139-159
0138-0338
2081-8262
Pojawia się w:
Polish Polar Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Modified Approach to Punctured Product Polar Codes
Autorzy:
Hanif, Mohammad Abu
Vafi, Sina
Powiązania:
https://bibliotekanauki.pl/articles/308633.pdf
Data publikacji:
2019
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
polar code
product code
punctured codes
iterative decoding
Opis:
A high-performance polar code introduced as a product polar code can be constructed by concatenating two short length polar codes. The punctured structure of this code was achieved by puncturing one of its constituent codes. The constructed polar code provided better performance than a single polar code in the error floor region. However, its performance in the waterfall region was not as good as that of single polar codes. This paper proposes a new puncturing algorithm for product codes constructed by two identical polar codes. Puncturing is conducted on both constituent codes, to ensure that the new code outperforms the previously punctured product polar and single polar codes. This is evident in both waterfall and error floor regions.
Źródło:
Journal of Telecommunications and Information Technology; 2019, 3; 63-69
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A method and a model for risk assessment of GNSS utilisation with a proof-of-principle demonstration for polar GNSS maritime applications
Autorzy:
Malić, E.
Sikirica, N.
Špoljar, D.
Filjar, R.
Powiązania:
https://bibliotekanauki.pl/articles/24201434.pdf
Data publikacji:
2023
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
GNSS
GNSS Positioning Performance Degradation
assessment of risk
lonospheric delay
intelligent maritime traffic
maritime applications
polar region
polar navigation
Opis:
The GNSS positioning performance is commonly defined and described in terms unspecified to particular GNSS-based application. The approach causes difficulties to GNSS application developers, operators, and users, rendering the impact assessment of GNSS performance on the GNSS application Quality of Service (QoS) particularly difficult. Here the Probability of Occurrence (PoO) Model is introduced, which allows for a risk assessment of the probability for the GNSS positioning accuracy failure to meet the requirements of the particular GNSS-based application. The proposed PoO Model development procedure requires a large set of position estimation errors observations, which shall cover a range of classes of positioning environment (space weather, troposphere, multi-path etc.) disturbances affecting GNSS positioning accuracy. As result, the PoO Model becomes a tool that returns the probability of failure in meeting the positioning accuracy requirements of the GNSS applications considered, thus providing the input for a GNSS deployment risk assessment. The proposed PoO Model and its development procedure are demonstrated in the case of polar region positioning environment, with raw GNSS pseudorange observations taken at the International GNSS Service (IGS) Network reference station Iqualuit, Canada are used for the PoO Model development. The PoO Model proof-of-principle is then used to estimate the probability of the unmet required positioning accuracy for a number of polar maritime navigation applications. Manuscript concludes with a discussion of the PoO Model benefits and shortcomings, a summary of contribution, and intentions for the future research.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2023, 17, 1; 43--50
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sea ice mechanics
Autorzy:
Paul, Felix
Schwarz, Carina
Audh, Riesna Reuben
Bluhm, J.
Johnson, Siobhan
MacHutchon, Keith
Mielke, Tommy
Mishra, A.
Rampai, Tokoloho
Ricken, Tim
Schwarz, Alexander
Skatulla, Sebastian
Thom, Andrea
Verrinder, Robyn
Schröder, Jörg
Vichi, Marcello
Lupascu, Doru C.
Powiązania:
https://bibliotekanauki.pl/articles/29519762.pdf
Data publikacji:
2023
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
sea ice mechanics
polar regions
review
Antarctic MIZ
Opis:
Earth System Models (ESM), simulating sea ice and its interaction with the atmosphere and open ocean, require reliable physical, chemical, and biological input from measurements. There is limited data available from the Marginal Ice Zone of the Antarctic, where sea ice growth mechanisms differ from the Arctic. The main objective of this study is to review existing work related to Antarctic sea ice and highlight gaps in the available literature. The mechanical properties of sea ice and the numerical modeling of sea ice across all scales are covered. We summarize the genesis, physical mechanics, static and dynamic properties, strength, toughness, and transport of young sea ice as well as medium to large scale observation. On the computational mechanics side large- and small-scale modeling, ocean-sea ice and atmosphere-sea ice models, as well as sea ice rheology models, sea ice fracture mechanics, and bio-geo-chemical interaction processes are captured. The synergy between the physical and computational mechanics brings to light missing information from both fields. Plain language summary (PLS) Sea ice determines the interaction of the ocean with the atmosphere in both the southern and northern hemispheres. Its formation and annual development is subject to mechanical interaction with ocean currents and winds. This review covers the mechanics of sea ice in the Antarctic and its relation to the Arctic covering experiment and modelling. Impact on the climate is discussed.
Źródło:
Computer Methods in Materials Science; 2023, 23, 3; 5-53
2720-4081
2720-3948
Pojawia się w:
Computer Methods in Materials Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ikona, świadek, ofiara. Niedźwiedź polarny jako figura wizualna dyskursu zmiany klimatu
Icon, witness, victim. The polar bear as a visual figure of the climate change discourse
Autorzy:
Piasecki, Michał
Powiązania:
https://bibliotekanauki.pl/articles/1927304.pdf
Data publikacji:
2021-09-21
Wydawca:
Łódzkie Towarzystwo Naukowe
Tematy:
polar bear
climate catastrophe
visual culture
embodiment
vulnerability
Opis:
The article focuses on the media practice of using visual representations of polar bears to illustrate information about climate change. It starts with a short description about the iconic status that climate discourse attributes to these type of images. The article addresses the question about how this iconic status is defined and what the media specificity of the polar bear is as a part of “charismatic megafauna.” These iconic properties are placed in contexts related to communicating issues related to climate change, and as a consequence the article emphasises the subsequent disappointment that these kind of representations have brought about. To begin with the article focuses on a reconstruction of the images of polar bears that were created at a time when it became a species in danger of extinction. Subsequently, the article characterizes the representations of the species in relation to the effects of climate change. The analysis refers to the typology proposed by Dorothea Born, who suggested that three types of such representations are namely: “anthropomorphized bears,” “bear in context,” “bear in danger.” Finally, the focus turns to the victimising dimension of these representations. When seen from the perspective of the polar bear as a victim, there is a need to emphasize the role of the suffering body, which can be seen as a common denominator in the human-non-human condition of vulnerability.
Źródło:
Zagadnienia Rodzajów Literackich; 2021, 64, 1; 71-86
0084-4446
Pojawia się w:
Zagadnienia Rodzajów Literackich
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Cap Formation Induced by Concanavalin A in Pathogenic Free-living Amoebae
Autorzy:
González-Robles, A.
Cristóbal-Ramos, A. R.
González-Lázaro, M.
Omaña-Molina, M.
Martínez-Palomo, A.
Powiązania:
https://bibliotekanauki.pl/articles/763565.pdf
Data publikacji:
2011
Wydawca:
Uniwersytet Jagielloński. Wydawnictwo Uniwersytetu Jagiellońskiego
Tematy:
Free-living amoebae, Con A, capping, polar redistribution
Opis:
Morphological differences in cap formation were found when trophozoites of different free-living amoebae were treated with the lectin Concanavalin A, which resulted in a rapid redistribution of certain surface components to form small clusters and membrane-folded structures of diverse sizes. Acanthamoeba castellanii, Acanthamoba polyphaga and Naegleria lovaniensis exhibited characteristic caps, however, in A. castellanii this structure was larger and included several folds of the plasma membrane; furthermore, some of these caps had vacuoles containing a fi bro granular content. In contrast, the caps formed by A. polyphaga and N. lovaniensis lacked vacuoles. Regarding Naegleria fowleri, the trophozoites did not produce a defi ned cap, and only small patches of lectin-bound surface receptor complexes were observed at one pole of the cell body. In the free-living amoebae studied, it was not possible to correlate the shape and size of cap with pathogenicity.
Źródło:
Acta Protozoologica; 2011, 50, 2
1689-0027
Pojawia się w:
Acta Protozoologica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Coccolithophorids in Polar Waters: Mercedesia gen. nov., Ericiolus, Quaternariella and Porsildia gen. nov.
Autorzy:
Thomsen, Helge A.
Østergaard, Jette B.
Powiązania:
https://bibliotekanauki.pl/articles/763740.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Jagielloński. Wydawnictwo Uniwersytetu Jagiellońskiego
Tematy:
coccolithophorid, Mercedesia, Ericiolus, Quaternariella, Porsildia, Polar Regions, electron microscopy
Opis:
Coccolithophorid samples from arctic and antartic regions have been examined for an update on species morphology, life history aspects and biogeography for the coccolithophorid genera Ericiolus and Quaternariella and two other genera here described as new. Mercedesia gen. nov. comprises three new species, M. aspiphora sp. nov. from both polar regions, the arctic M. multistellata sp. nov. and the Antarctic M. pusilla sp. nov. The genus is characterized by its monomorphic nannoliths that are shaped like three-armed stars. The new arctic monospecific genus Porsildia gen. nov. is established for the heterococcolith-bearing species P. acerviphora sp. nov. Combination cells, from the arctic region, bearing holococcoliths of Quaternariella obscura and previously undescribed heterococcoliths, with a Papposphaeracean affinity, are described here for the first time.
Źródło:
Acta Protozoologica; 2015, 54, 3
1689-0027
Pojawia się w:
Acta Protozoologica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sterowanie prędkością silnika krokowego z zastosowaniem mikrokontrolera ATmega8
Control of a step motor speed with the use of an ATmega8 microcontroller
Autorzy:
Bączek, Ł.
Głowacz, Z.
Powiązania:
https://bibliotekanauki.pl/articles/187503.pdf
Data publikacji:
2011
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Technik Innowacyjnych EMAG
Tematy:
silnik krokowy bipolarny
sterowniki
bi-polar step motor
controller
Opis:
Zaprojektowano i wykonano sterownik silnika krokowego bipolarnego. Sterownik składa się z mikrokontrolera ATmega8, programatora, mostka typu H umożliwiającego zmianę kierunku obrotów silnika, stabilizatora napięcia, który posiada wbudowane ograniczenia: prądowe, termiczne oraz zabezpieczenie przed opuszczeniem obszaru bezpiecznej pracy, LCD - alfanumerycznego wyświetlacza. Konstrukcja sterownika pozwala na jego rozbudowę.
A controller of a bi-polar step motor was designed and manufactured. The controller consists of an ATmega8 microcontroller, programmer, H bridge enabling the change of the motor rotating direction, voltage stabilizer with built-in current- and thermal limits as well as protection against leaving a safe operating area, and finally an LCD alphanumeric display. The construction of the controller allows its extension.
Źródło:
Mechanizacja i Automatyzacja Górnictwa; 2011, R. 49, nr 10, 10; 5-10
0208-7448
Pojawia się w:
Mechanizacja i Automatyzacja Górnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Chromatographic Behaviour and Analytical Method Development for Metformin HCl: Application to Permeation Studies through Caco-2 Cells
Autorzy:
Hamdan, Imad I.
Farah, Dua'a G.
Abu-Dahab, Rana Abu-Dahaba
Powiązania:
https://bibliotekanauki.pl/articles/895723.pdf
Data publikacji:
2020-02-29
Wydawca:
Polskie Towarzystwo Farmaceutyczne
Tematy:
permeability
metformin
Caco-2 cells
polar compounds
ion pairs
Opis:
Metformin HCl (Mtf) is a polar compound with low bioavailability. Counter ions have been shown to improve the bioavailability of polar ionizable drugs. The goal of this work was to develop an HPLC method that is capable of separating and quantifying Mtf from a group of selected organic anions: diclofenac sodium (DS), citric acid (CA), hydroxyl cinnamic acid (HCA), 8-anilinonaphthalene-1-sulfonic acid (ANS),and trisodium phosphate (TSP). Thus, the effect of the mixture of anions on the transport of Mtf through Caco-2 cells could be studied. During the development of the method, interesting chromatographic behaviors of Mtf were observed using a polar stationary phase (Hypersil® SAS, C1). The developed method was validated and found to be linear in the range 2-100 µg/mL with good accuracy and precision. The method was applied for transport experiments of Mtf across Caco-2 cells in the presence and absence of organic anions. Apparent permeability coefficients (Papp) were calculated. The Papp of Mtf was increased in the presence of CA and DS from 3.37×10-6 cm/s to 5.08×10-6 and 4.25×10-6 cm/s respectively, while it was decreased to 1.9×10-6 cm/s (p-value 0.01) in the presence of HCA. Interestingly, the Papp for Mtf increased more than four-fold when present with both calcium and CA together, which might lead to significant improvement in the bioavailability of the drug.
Źródło:
Acta Poloniae Pharmaceutica - Drug Research; 2020, 77, 1; 11-21
0001-6837
2353-5288
Pojawia się w:
Acta Poloniae Pharmaceutica - Drug Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The influence of short-term cold stress on the metabolism of non-structural carbohydrates in polar grasses
Autorzy:
Giełwanowska, Irena
Łopieńska-Biernat, Elżbieta
Pastorczyk, Marta
Żółtowska, Krystyna
Stryiński, Robert
Ewa Zaobidna
Powiązania:
https://bibliotekanauki.pl/articles/2046772.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Antarctic
Arctic
carbohydrates
cold stress
enzymes
Poaceae
polar plants
Źródło:
Polish Polar Research; 2017, 38, 2; 187-204
0138-0338
2081-8262
Pojawia się w:
Polish Polar Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Invertebrate communities of the High Arctic ponds in Hornsund
Autorzy:
Luoto, Tomi P.
Mimmi Oksman
Ojala, Antti E.K.
Powiązania:
https://bibliotekanauki.pl/articles/2046863.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
aquatic invertebrates
Arctic
bird impact
climate change
polar lakes
Źródło:
Polish Polar Research; 2016, 37, 1; 105-119
0138-0338
2081-8262
Pojawia się w:
Polish Polar Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Grain Crushing on Shear Localization in Granular Bodies within Micro-Polar Hypoplasticity
Autorzy:
Tejchman, J.
Powiązania:
https://bibliotekanauki.pl/articles/241516.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
breakage mechanics
grain crushing
micro-polar hypoplasticity
sand
shearing
Opis:
The paper deals with the effect of grain crushing on shear localization in granular materials in an infinite long narrow granular strip under constant vertical pressure. The calculations were carried out with an enhanced micro-polar hypoplastic constitutive model which is able to describe the salient properties of crushable granular bodies including shear localization. The change of the mean grain diameter with varying pressure was taken into account with the help of formulae from breakage mechanics. The effect of pressure and initial void ratio on shear localization was studied.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2010, 57, 1; 3-30
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of the ITSG-GRACE daily models in the determination of polar motion excitation function
Autorzy:
Partyka, Aleksander
Nastula, Jolanta
Śliwińska, Justyna
Kur, Tomasz
Wińska, Małgorzata
Powiązania:
https://bibliotekanauki.pl/articles/27314474.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Centrum Badań Kosmicznych PAN
Tematy:
GRACE
hydrological angular momentum
Earth rotation
polar motion excitation
Opis:
The main aim of this study is to evaluate the usefulness of Institute of Geodesy at Graz University of Technology (ITSG) daily gravity field models in the determination of hydrological angular momentum (HAM) at nonseasonal time scales. We compared the equatorial components (χ1 and χ2) of HAM calculated with the ITSG daily gravity field models (ITSG-Gravity Recovery and Climate Experiment [ITSG-GRACE] 2016 and ITSG-GRACE 2018) with HAM and sea-level angular momentum (SLAM) from hydrological land surface discharge model (LSDM) and the hydrological signal in the polar motion excitation (known as geodetic residuals [GAO]). Data from ITSG have a daily temporal resolution and allow us to determine oscillations with higher frequencies than the more commonly used monthly data. We limited our study to the period between 2004 and 2011 because of the gaps in GRACE observations before and after this period. We evaluated HAM obtained from ITSG GRACE models in spectral and time domains and determined the amplitude spectra of the analyzed series in the spectral range from 2 to 120 days. Our analyses confirm the existence of a sub-monthly signal in the HAM series determined from ITSG daily data. We observed a similar signal in LSDM-based HAM, but with notably weaker amplitudes. We also observed common peaks around 14 days in the amplitude spectra for the GAO- and ITSG-based series, which may be related to the Earth’s tides. ITSG daily gravity field models can be useful to determine the equatorial components of HAM at nonseasonal time scales.
Źródło:
Artificial Satellites. Journal of Planetary Geodesy; 2023, 58, 3; 105--121
2083-6104
Pojawia się w:
Artificial Satellites. Journal of Planetary Geodesy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Medium- and long-term prediction of polar motion using weighted least squares extrapolation and vector autoregressive modeling
Autorzy:
Lei, Yu
Zhao, Danning
Guo, Min
Powiązania:
https://bibliotekanauki.pl/articles/27314482.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Centrum Badań Kosmicznych PAN
Tematy:
polar motion
prediction model
weighted least squares
vector autoregressive
Opis:
This article presents the application of weighted least squares (WLS) extrapolation and vector autoregressive (VAR) modeling in polar motion prediction. A piecewise weighting function is developed for the least squares (LS) adjustment in consideration of the effect of intervals between observation and prediction epochs on WLS extrapolation. Furthermore, the VAR technique is used to simultaneously model and predict the residuals of xp, yp pole coordinates for WLS misfit. The simultaneous predictions of xp, yp pole coordinates are subsequently computed by the combination of WLS extrapolation of harmonic models for the linear trend, Chandler and annual wobbles, and VAR stochastic prediction of the residuals (WLS+VAR). The 365-day-ahead xp, yp predictions are compared with those generated by LS extrapolation+univariate AR prediction and LS extrapolation+VAR modeling. It is shown that the xp, yp predictions based on WLS+VAR taking into consideration both the interval effect and correlation between xp and yp outperform those generated by two others. The accuracies of the xp predictions are 13.97 mas, 18.47 mas, and 20.52 mas, respectively for the 150-, 270-, and 365-day horizon in terms of the mean absolute error statistics, 36%, 24.8%, and 33.5% higher than LS+AR, respectively. For the yp predictions, the 150-, 270-, and 365-day accuracies are 15.41 mas, 21.17 mas, and 21.82 mas respectively, 27.4%, 11.9%, and 21.8% higher than LS+AR respectively. Moreover, the absolute differences of the WLS+VAR predictions and observations are smaller than the differences from LS+VAR and LS+AR, which is practically important to practical and scientific users, although the improvement in accuracies is no more than 10% relative to LS+VAR. The further comparison with the predictions submitted to the 1st Earth Orientation Parameters Prediction Comparison Campaign (1st EOP PCC) shows that while the accuracy of the predictions within 30 days is comparable with that by the most accurate prediction techniques including neural networks and LS+AR participating in the campaign for xp, yp pole coordinates, the accuracy of the predictions up to 365 days into the future are better than accuracies by the other techniques except best LS+AR used in the EOP PCC. It is therefore concluded that the medium- and long-term prediction accuracy of polar motion can be improved by modeling xp, yp pole coordinates together.
Źródło:
Artificial Satellites. Journal of Planetary Geodesy; 2023, 58, 2; 42--55
2083-6104
Pojawia się w:
Artificial Satellites. Journal of Planetary Geodesy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stability of vessels in an ice-free Arctic
Autorzy:
Johansen, K.
Sollid, M. P.
Gudmestad, O. T.
Powiązania:
https://bibliotekanauki.pl/articles/1841599.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
Ice-Free Arctic
Maritime Education and Training
stability of vessels
ship stability
Icing
marine Icing model
Polar Low
IMO Polar Code
Opis:
One consequence of the declining ice cover in the Arctic is increased areas of open seas. These new open sea areas lead to some challenging aspects related to ship stability. Longer fetch lengths, associated with build-up of larger waves followed by increased conditions for sea spray icing on vessels is one aspect. Open seas in combination with cold atmospheric temperatures is a prerequisite for polar low pressures to occur. Polar lows may represent an additional aspect of increased icing on vessels by heavy snow in addition to extensive sea spray ice accretion. Over the last decades, different formulas for prediction of sea spray ice accretion rate on ships were developed to form basis for ice accretion warnings. Some of these formulas seem to have certain limitations and appear to be conservative. Important limitations of some formulas are considerations regarding heat flux, relationship between wind and waves, and ice accretion related to Polar lows. This paper will take a closer look at the accuracy and the realism of different ice accretion formulas and, related to this aspect, we will also discuss whether ship officer candidates receive sufficient maritime education and training (MET) related to realistic ice accretion and ship icing aspects.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2020, 14, 3; 663-671
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Use of simulator training to mitigate risks in Arctic shipping operations
Autorzy:
Røds, J. F.
Gudmestad, O. T.
Powiązania:
https://bibliotekanauki.pl/articles/949947.pdf
Data publikacji:
2019
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
maritime education and training (MET)
simulator training
maritime simulator training
Arctic Shipping Operations
polar code
polar region
risk reducing
risk reducing measure
Opis:
Over the recent years, ship traffic in the polar areas has increased. There is reason to believe that this traffic, and especially the cruise traffic, will increase further as the ice retracts towards the poles. There is also reason to believe that with the continued focus and exposure of the Polar Region, the cruise tourism to the region will grow. The increased presence in the polar areas will create positive repercussions for several actors, both on sea and land. There will, however, also be challenges associated with the growing presence in the polar areas. Vessels will be operating at long distances to other vessels and land infrastructures. These vessels will also be operating in climate and conditions that will put extra pressure on both vessel and crew. These challenges need to be solved in order for the ship industry to operate safely in the Polar Region. To ensure that companies operating in these areas identify and manage these challenges, the International Maritime Organization (IMO) developed the Polar Code (2017) with the intent of increasing the safety for vessels operating in polar waters, and to reduce the impact on humans and environment in this remote, vulnerable and harsh area. This code defines a number of requirements, with which the vessels should operate in accordance with. In this paper, we reveal which challenges the vessel and its crew need to deal with when navigating in polar waters. The challenges will be analysed and assessed through the use of a preliminary qualitative risk analysis to determine the potential hazards the vessel is exposed to under operations in polar waters, and to find out what level of risk the different hazards represents for the vessel and its crew. The main objective of the paper is to find out how the risk levels can be reduced, with particular focus on the use of simulator training as a risk reducing measure. The final goal is to measure the risk towards acceptance criteria, which have been determined prior to conducting the analysis.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2019, 13, 2; 375-379
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
FE-modelling of behaviour of granular anchors in rock and soils
Autorzy:
Wehr, J.
Tejchman, J.
Powiązania:
https://bibliotekanauki.pl/articles/1954551.pdf
Data publikacji:
2000
Wydawca:
Politechnika Gdańska
Tematy:
anchor
finite element method
granular materials
hypoplasticity
polar continuum
Opis:
The paper is concerned with granular anchors in rock and soils. Model tests and numerical calculations were performed. The effect of different parameters on the behaviour of anchors was investigated: anchor length, anchor diameter, initial density and mean grain diameter of the granular material, anchor roughness and stiffness of the borehole wall. The experiments were modelled with a finite element method and a polar hypoplastic constitutive relation. The relation can capture the salient properties of granular materials during shearing. A satisfactory agreement between experiments and numerical calculations was obtained. Advantages and limitations of granular anchors in rock and soils were outlined.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2000, 4, 3; 517-526
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The evolution of strain localisation in a hypoplastic cosserat material under shearing
Autorzy:
Bauer, E.
Huang, W.
Powiązania:
https://bibliotekanauki.pl/articles/1954558.pdf
Data publikacji:
2000
Wydawca:
Politechnika Gdańska
Tematy:
localisation
granular materials
polar effects
shearing
finite element method
Opis:
Numerical studies of the evolution of strain localisation and polar effects within a plane layer of a granular material under monotonic shearing are presented. Herein a micro-polar approach is formulated within the framework of a hypoplastic Cosserat continuum to describe the essential properties of a dry and cohesionless granular material like sand. The constitutive model is based on incremental non-linear tensor-valued functions and captures the influence of the pressure, the void ratio, the mean grain diameter and the rotation resistance of the grains on the evolution of the stresses and couple stresses. The Cosserat boundary conditions are suitable to model the rotation resistance at the interface between the granular layer and the surfaces adjoining the boundaries of the granular body. The numerical investigations show that the location, thickness and evolution of strain localisation within the shear layer are strongly influenced by the boundary conditions and the initial state quantities.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2000, 4, 3; 469-483
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
FE studies of quasi-static mass flow in bins: the polar elasto-plastic approach
Autorzy:
Tejchman, J.
Powiązania:
https://bibliotekanauki.pl/articles/1955765.pdf
Data publikacji:
2003
Wydawca:
Politechnika Gdańska
Tematy:
elasto-plasticity
finite element method
flow
polar approach
silo
Opis:
The paper deals with numerical modelling of confined flow of granular materials in vertical bins. Quasi-static mass flow of non-cohesive sand with a controlled outlet velocity along the entire silo bottom was numerically studied using a finite element method taking into account an elasto-plastic constitutive law laid down within a Cosserat continuum. The influence of the initial density and the mean grain diameter of the solid, wall roughness, wall stiffness and imperfection, the initial stress state and the pressure level on the stress and deformation states in plane-strain vertical bins was investigated. The numerical results were compared with similar model tests performed with a rectangular vertical bin containing sand. The calculated results were in satisfactory agreement with the experimental ones. The advantages and limitations of the polar elasto-plastic approach to model granular silo flow were outlined.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2003, 7, 4; 667-699
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ornithological observations in the Subarctic zone of the Polar Ural
Autorzy:
Wuczyński, Andrzej
Hada-Jasikowski, Grzegorz
Powiązania:
https://bibliotekanauki.pl/articles/2052486.pdf
Data publikacji:
1997
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Subarctic
Polar Ural-Russia
tundra
breeding avifauna
habitat selectivity
Źródło:
Polish Polar Research; 1997, 18, 2; 119-133
0138-0338
2081-8262
Pojawia się w:
Polish Polar Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Generalized F tests and selective generalized F tests for orthogonal and associated mixed models
Autorzy:
Nunes, Célia
Pinto, Iola
Mexia, João
Powiązania:
https://bibliotekanauki.pl/articles/729658.pdf
Data publikacji:
2008
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
selective generalized F tests
generalized polar coordinates
associated models
Opis:
The statistics of generalized F tests are quotients of linear combinations of independent chi-squares. Given a parameter, θ, for which we have a quadratic unbiased estimator, θ̃, the test statistic, for the hypothesis of nullity of that parameter, is the quotient of the positive part by the negative part of such estimator. Using generalized polar coordinates it is possible to obtain selective generalized F tests which are especially powerful for selected families of alternatives. We build both classes of tests for the orthogonal and associated mixed models. The associated models are obtained adding terms to the orthogonal models.
Źródło:
Discussiones Mathematicae Probability and Statistics; 2008, 28, 2; 229-246
1509-9423
Pojawia się w:
Discussiones Mathematicae Probability and Statistics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Closed-loop control algorithm for some class of nonholonomic systems using polar representation
Autorzy:
Pazderski, D.
Szulczyński, P.
Kozłowski, K.
Powiązania:
https://bibliotekanauki.pl/articles/201607.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
polar coordinates
nonholonomic system
discontinuous stabilization at the origin
Opis:
This paper is focused on the convergence problem defined for some class of a two input affine nonholonomic driftless system with three-dimensional state. The problem is solved based on a polar transformation which is singular at the origin. The convergence is ensured using static-state feedback. The necessary conditions for construction of the algorithm are formally discussed. The solution, in general, is local, and the feasible domain is strictly related to the properties of the control system. In order to improve algorithm robustness a simple hybrid algorithm is formulated. The general theory is illustrated by two particular systems and the results of numerical simulations are provided.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2012, 60, 3; 521-535
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dorobek ośrodka wrocławskiego w meteorologii i klimatologii obszarów polarnych
University of Wroclaw achievements in polar meteorology and climatology
Autorzy:
Migała, K.
Piasecki, J.
Pereyma, J.
Powiązania:
https://bibliotekanauki.pl/articles/260884.pdf
Data publikacji:
2015
Wydawca:
Stowarzyszenie Klimatologów Polskich
Tematy:
historia badań polarnych
meteorologia i klimatologia polarna
Uniwersytet Wrocławski
Hornsund
Spitsbergen
history of polar research
polar meteorology and climatology
University of Wroclaw
Opis:
W niniejszym artykule dokonano syntezy dorobku ośrodka wrocławskiego w meteorologii i klimatologii polarnej, wskazano też na momenty przełomowe ale też kryzysowe w tej 60-letniej historii. Efektem ostatnich lat jest aktywność badawcza, która ma cechy innowacji i zastosowania meteorologii/klimatologii na pograniczu dziedzin (glacjologia, geomorfologia, biologia, chemia atmosfery). Cechą charakterystyczną badań wrocławskich geografów nadal pozostaje duże zaangażowanie w trudnych i nowatorskich tematach. Wyniki badań mają często charakter interdyscyplinarny. Spoglądając na dorobek wrocławski i innych ośrodków naukowych powinniśmy mieć świadomość, że dopiero nowoczesność stosowanych metod pomiarowych i narzędzi analiz nada polskiej klimatologii polarnej odpowiednią wartość naukową w wymiarze europejskim.
This paper summarizes the University of Wroclaw achievements in polar meteorology and climatology. An attempt was made to identify milestones but also critical points in the 60-year history. Resumed after years of absence activity seems to be innovative with applications in many scientific branches (glaciology, geomorphology, biology, chemistry of atmosphere). A feature of geographers from Wroclaw still is a strong commitment to challenging and innovative topics, with results which are often interdisciplinary. Looking at the achievements of Wroclaw and other polish research centers should be aware that only modern methods of measurement and analysis tools will give the Polish polar climatology adequate scientific value of a European dimension.
Źródło:
Problemy Klimatologii Polarnej; 2015, 25; 9-18
1234-0715
Pojawia się w:
Problemy Klimatologii Polarnej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Semi-empirical equation for the prediction of retention in normal phase liquid chromatography (NP-LC) with polar bonded stationary phases
Autorzy:
Zapała, W.
Zapała, L.
Powiązania:
https://bibliotekanauki.pl/articles/346965.pdf
Data publikacji:
2008
Wydawca:
Politechnika Bydgoska im. Jana i Jędrzeja Śniadeckich. Wydział Technologii i Inżynierii Chemicznej
Tematy:
retention prediction
retention models
polar bonded stationary phase
NP-HPLC
Opis:
A semi-empirical heterogeneous adsorption model for the accurate prediction of analyte retention in a column chromatography with binary mobile phase on polar bonded adsorbent surface was proposed. The performance of the proposed equation was compared with two retention models reported in the literature. All models were verified for different LC systems by means of four criteria: the sum of squared differences between the experimental and theoretical data, approximation of standard deviation, Fisher test and F-test ratio.
Źródło:
Ars Separatoria Acta; 2008, 6; 15-30
1731-6340
Pojawia się w:
Ars Separatoria Acta
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The attractiveness of polar regions as the zones of silence
Autorzy:
Mamzer, H.
Powiązania:
https://bibliotekanauki.pl/articles/2079050.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
polar region
attractiveness
silence zone
natural specificity
isolation
anthropopressure
tourism
Opis:
Post-modern societies are characterized by information-based functions that gen- erate the anthropogenic stimuli (as opposed to the industrial society of energy processing and the traditional society whose activities are related to the production of natural crops). Hence, life in the information overload becomes a tiresome daily reality, from which only a very few may escape. These escapers might be regarded as consumers of the new type of ‘luxury goods’ such as: silence experiencing and positively valorized solitude allowing deeper insight into one- self. The polar regions provide an opportunity to withdraw from the anthropogenic noise of the civilization. I do believe that it is one of the most significant drivers of the increasing popularity of traveling to these regions of the world.
Źródło:
Oceanologia; 2020, 62, 4PB; 557-564
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Punk’s not dead, even at the Czech Arctic Scientific Station in Svalbard
Autorzy:
Lycka, Z.
Elster, J.
Powiązania:
https://bibliotekanauki.pl/articles/2079063.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
Czech Arctic Scientific Station
Svalbard
infrastructure
polar research
scientific research
Opis:
In the last few years, the newly opened Czech Arctic Scientific Infrastructure in Svalbard – Josef Svoboda Station – has closely collaborated with UiT – The Arctic University of Norway on very productive research related to climate change and the impact of the sea and land ice disappearance. Professor Josef Elster, the Head of the Czech station and a researcher in the diversity, ecology and ecophysiology of polar algae and cyanobacteria, and the glacial microbiologist Marie Šabacká and their team try to find the answer to questions concerning how the Arctic ecosystem responds to global warming and how global warming affects human activity. The results of their research can be used, for example, in the treatment and refinement of drinking and sewage water, the pharmaceutical industry and medicine, livestock nutrition including aquaculture and in the production of nutritional supplements for people. However, even the most exciting scientific information and results are not readily available to a non-professional audience. Interdisciplinarity and a suitable cultural framework can bring new life to the results of scientific research. If the presentation of science is interconnected with cultural disciplines such as literature, art, music or theatre, its account can be enriched and media interest can be increased. The scientific-cultural festivals AT HOME IN SVALBARD 2018 and ARCTIC FESTIVAL 2019 are just two good examples. The presentation of scientific research through culture is a very distinctive and innovative attempt. Moreover, the interest of the public can influence the stakeholders’ approach to providing and increasing finances for further scientific research.
Źródło:
Oceanologia; 2020, 62, 4PB; 622-627
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-50 z 173

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