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Wyszukujesz frazę "marine condition" wg kryterium: Temat


Tytuł:
Aalenian to Cenomanian terrestrial palynofloras of SW Scania, Sweden
Autorzy:
Vajda, V
Powiązania:
https://bibliotekanauki.pl/articles/23372.pdf
Data publikacji:
2001
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
pollen
palynoflora
Cenomanian
Cretaceous
paleovegetation
palynology
Scania
Sweden
paleoclimate
marine condition
spore
paleontology
Opis:
I describe dispersed miospore assemblages recovered from 35 drill-core samples from Höllviken 2, Norrevång 1, and Svedala 1 wells, all in SW Scania, Sweden. Over eighty taxa of pollen and spores, ranging from the Aalenian to the Cenomanian were identified. Four pollen/spore zones have been defined on the basis of key taxa and on the variation in the frequency of miospore groups. The palynofacies analysis indicates that a continental depositional environment prevailed during the Aalenian in Scania. A stratigraphic hiatus existed from the Aalenian then on until the Valanginian, when the depositional environment subsequently became marine. The marine conditions continued until the Cenomanian. A gradual increase in marine palynomorphs is found in the Cenomanian succession, indicating a transgression. On the basis of the palynoflora it is suggested that the vegetation consisted of cycads, conifers, pteridophytes and a very limited number of angiosperms.
W pracy opisano rozproszone zespoły miospor pochodzące z 35 próbek rdzeni wiertniczych z otworów Höllviken 2, Norrevång 1 i Svedala 1, położonych w południowo-zachodniej Skanii, w Szwecji. Oznaczono ponad osiemdziesiąt taksonów pyłku i zarodników, wieku od aalenu po cenoman. Wyznaczono cztery poziomy pyłkowo-zarodnikowe na podstawie taksonów przewodnich i zmian częstości występowania poszczególnych grup miospor. Analiza palinofacjalna wskazuje, że w aalenie przeważało w Skanii kontynentalne środowisko sedymentacyjne. Luka stratygraficzna trwała od aalenu do walanżynu, kiedy to zapanowal morski reżim sedymentacyjny, trwający aż do cenomanu. Stopniowy wzrost udziału form morskich w sukcesji cenomańskiej wskazuje na transgresję. Zbadana palinoflora wskazuje na to, że w kredzie przeważaly na badanym obszarze sagowce, szpilkowe, paprotniki i nieliczne okrytozalążkowe.
Źródło:
Acta Palaeontologica Polonica; 2001, 46, 3
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Galveston Bay dynamics under different wind conditions
Autorzy:
Salas-Monreal, D.
Anis, A.
Salas-de-Leon, D.A.
Powiązania:
https://bibliotekanauki.pl/articles/48132.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
suspended particle
dispersion
shallow estuary
Galveston Bay
dynamics
wind condition
marine ecosystem
Źródło:
Oceanologia; 2018, 60, 2
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Holocene evolution of the Pomeranian Bay environment, Southern Baltic Sea
Autorzy:
Kostecki, R.
Janczak-Kostecka, B.
Powiązania:
https://bibliotekanauki.pl/articles/48852.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
aerobic condition
anaerobic condition
Ancylus Lake
Baltic Sea
diatom assemblage
ecological group
geochemistry
Holocene
lacustrine sediment
marine diatom
marine environment
paleogeographic development
Pomeranian Bay
sediment core
shallow lake
Opis:
This article focuses on the diatom assemblages and geochemical composition of sediment cores retrieved from the Pomeranian Bay. We also discuss similarities and differences in the diatom assemblages and the palaeogeographic development of nearby regions. Our main objective was to determine the characteristics and rate of the Littorina transgression in the Pomeranian Bay area. Sediments were divided into units based on differences in the distribution of diatom ecological groups and in geochemical ratios, such as Mg/Ca, Na/K and Fe/Mn. This study identified lacustrine sediments deposited during the time of the Ancylus Lake. This lacustrine-period sedimentation took place in a shallow lake under aerobic conditions. The record of the onset of marine environment dates to 8900–8300 cal BP and corresponds to the Littorina transgression. After about 8300 cal BP, sedimentation took place in a deeper marine environment with higher biogenic production and anaerobic conditions. The abrupt appearance of marine diatom species and increased geochemical salinity indicators reflect the large impact of the Littorina transgression on the Pomeranian Bay environment.
Źródło:
Oceanologia; 2011, 53, (1-TI)
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Statistical Studies on Marine Accidents Happened on the Bohai Sea
Autorzy:
Wu, Z.
Zhao, J.
Li, G.
Powiązania:
https://bibliotekanauki.pl/articles/116959.pdf
Data publikacji:
2008
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
Marine Accidents
Ship Accidents
Marine Traffic Accidents
Chinese Navigable Waterways
Weather Condition
Decision Making Process
Human Factor
Statistical Study
Opis:
a statistical study is carried out on the basis of information of marine traffic accidents occurred from 1996 to 2005 on the Bohai Sea. The time distribution and geographic distribution of the marine traffic accidents, as well as the relationships between the accidents and weather condition, type of accidents area, accident category, size of ships are analyzed, which provide references for adopting safety decision-making and take relative precautionary measures to avoid and decrease occurrence of accidents.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2008, 2, 2; 183-186
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synoptic conditions governing upwelling along the Polish Baltic coast
Autorzy:
Bednorz, E.
Polrolniczak, M.
Czarnecki, B.
Powiązania:
https://bibliotekanauki.pl/articles/49142.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
synoptic condition
upwelling
Baltic Sea
Baltic coast
sea surface temperature
marine ecosystem
sea level pressure
wind direction
wind speed
weather condition
Źródło:
Oceanologia; 2013, 55, 4
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Marine Navigation Using Expert System
Autorzy:
Nikitakos, N.
Fikaris, G.
Powiązania:
https://bibliotekanauki.pl/articles/117046.pdf
Data publikacji:
2009
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
marine navigation
Expert System
Safety of Navigation
Weather Condition
Loading Condition
decision support system (DSS)
Case Based Reasoning (CBR)
Computer Simulation
Opis:
A ship’s autopilot adjustment is a matter of utmost importance since it affects its safety, command as well as fuel and time efficiency. A number of methods have been developed in order to cope with this issue usually based on models that simulate the weather conditions and adjust the device accordingly. Some of them have a considerable degree of success but none dealt with the problem completely. The main obstacles are the difficulty of simulating the infinite weather and loading conditions and to properly represent them with mathematical equations or rules. This paper describes a method of selecting the best out of a pre-existing set of configurations, taking into account any weather situation, loading condition and type of ship. Moreover, the selected configuration can improve itself during the entire life cycle of the vessel, since it fine tunes its properties for better results. This approach uses Case Based Reasoning as its core technology and is a part of a hybrid system that analyses and solves prefixed problems of maritime interest.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2009, 3, 3; 251-259
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multiparameter approximation model of temperature conditions of marine diiesel generator sets, based on Markov chain Monte Carlo
Autorzy:
Myrhorod, V.
Hvozdeva, I.
Budashko, V.
Powiązania:
https://bibliotekanauki.pl/articles/24201416.pdf
Data publikacji:
2022
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
marine diesel engine
Markov chain Monte Carlo
temperature condition
multi-parameter approximation model
marine diesel generator
markov model
diagnostics
technical diagnostics
Opis:
In the article we propose a multi-parameter approximation model, based on Markov chain Monte Carlo, which describes the relationship between the temperature regime, operating conditions and electromechanical parameters of marine diesel generator sets. The approximation model is constructed on the basis of the analysis of experimental data of the exhaust gases temperature of marine diesel generator sets in their long-term operation. As a statistical model of random processes of temperature deviations from the approximation model, a Markov process model is proposed that takes into account the possible correlation of the initial data. Since the measuring channels of modern diagnostic systems are digital, due to discretization in time and level, the studied processes form a Markov chain, which makes it possible to establish the important features of such processes. The use of approximation models ensures the stationarity conditions and the correctness of the proposed Markov model in the conditions of multi-mode operation of marine diesel generator sets. The proposed multi-parameter approximation model, based on Markov chain Monte Carlo, allows you to take into account random perturbations that lead to a random change in the output coordinates of the diagnostic object. The proposed improvement of the model makes it possible to ensure its adequacy to real processes of changing the parameters of the temperature regimes of marine diesel generator sets. The proposed multi-parameter approximation model, based on Markov chain Monte Carlo, can be used in the systems of technical diagnostics of marine diesel generator sets in order to increase the reliability of diagnostic conclusions.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2022, 16, 4; 779--784
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Bioaccumulation of gamma emitting radionuclides in red algae from the Baltic Sea under laboratory conditions
Autorzy:
Zalewska, T.
Saniewski, M.
Powiązania:
https://bibliotekanauki.pl/articles/48962.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
Baltic Sea
bioaccumulation
environment pollution
Furcellaria lumbricalis
heavy metal
laboratory condition
macroalga
marine alga
marine organism
Polysiphonia fucoides
radionuclide
red alga
Opis:
The bioaccumulation ability of radionuclides 51Cr, 54Mn, 57Co, 60Co, 65Zn, 85Sr, 109Cd, 110mAg, 113Sn, 137Cs and 241Am in two red algae species from the southern Baltic Sea – Polysiphonia fucoides and Furcellaria lumbricalis – was determined under laboratory conditions. P. fucoides demonstrated better bioaccumulative properties towards most of the investigated radionuclides. As a result, P. fucoides can be recommended as a good bioindicator of radioactive environmental pollution. The bioaccumulation of radionuclides in F. lumbricalis was studied during an extended laboratory experiment. The initial extensive uptake of radioisotopes was followed by the rapid removal of cations; in general, concentrations tended to decrease with time. 137Cs displayed a different behaviour, its concentration in the algae increasing over time mainly due to its large ion radius; this is a factor that could be responsible for the stronger mechanical and chemical bonding of Cs+ and that could hamper the movement of ions in both directions.
Źródło:
Oceanologia; 2011, 53, 2
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An experimental study of the effects of cylinder lubricating oils on the vibration characteristics of a two-stroke low-speed marine diesel engine
Autorzy:
Wu, Gang
Jiang, Guodong
Chen, Changsheng
Jiang, Guohe
Pu, Xigang
Chen, Biwen
Powiązania:
https://bibliotekanauki.pl/articles/34603764.pdf
Data publikacji:
2023
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
two-stroke
low-speed marine diesel engine
cylinder lubricating oils
vibration characteristic
condition monitoring
Opis:
Two-stroke, low-speed diesel engines are widely used in large ships due to their good performance and fuel economy. However, there have been few studies of the effects of lubricating oils on the vibration of two-stroke, low-speed diesel engines. In this work, the effects of three different lubricating oils on the vibration characteristics of a low-speed engine are investigated, using the frequency domain, time-frequency domain, fast Fourier transform (FFT) and short-time Fourier transform (STFT) methods. The results show that non-invasive condition monitoring of the wear to a cylinder liner in a low-speed marine engine can be successfully achieved based on vibration signals. Both the FFT and STFT methods are capable of capturing information about combustion in the cylinder online in real time, and the STFT method also provides the ability to visualise the results with more comprehensive information. From the online condition monitoring of vibration signals, cylinder lubricants with medium viscosity and medium alkali content are found to have the best wear protection properties. This result is consistent with those of an elemental analysis of cylinder lubrication properties and an analysis of the data measured from a piston lifted from the cylinder after 300 h of engine operation.
Źródło:
Polish Maritime Research; 2023, 4; 92-101
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sea salt in aerosols over the Southern Baltic. Part 1. The generation and transportation of marine particles
Autorzy:
Lewandowska, A.U.
Falkowska, L.M.
Powiązania:
https://bibliotekanauki.pl/articles/48601.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
sea salt
marine aerosol
chemical composition
chloride ion
sulphate ion
Baltic Sea
wind condition
air mass
coastal zone
meteorological condition
wind speed
Źródło:
Oceanologia; 2013, 55, 2
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Static and dynamic properties of surfactant films on natural waters
Autorzy:
Pogorzelski, S.J.
Kogut, A.D.
Powiązania:
https://bibliotekanauki.pl/articles/49159.pdf
Data publikacji:
2001
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
natural water
Mediterranean Sea
dynamic property
water condition
surfactant
marine film
Baltic Sea
viscoelasticity
static property
Opis:
The paper contains the results of natural surface film surface pressure – area experiments carried out in inland waters and shallow offshore regions of the Baltic and Mediterranean Seas during 1990–99 under calm water conditions using the Langmuir trough – Wilhelmy filter paper plate system, which ‘cuts out’ an undisturbed film-covered sea area without any initial physico-chemical sample processing. The limiting specific area Alim (268–3157 ˚A2/molecule−1) and mean molecular mass (0.65–9.7 kDa) of microlayer surfactants were determined from the 2D virial equation of state applied to the isotherms. Film structure signatures were derived from π − A isotherm hysteresis and application of the 2D polymer scaling theory. The stress-relaxation measurements revealed a two-step relaxation process at the interface with characteristic times τ1 (1.1–2.8) and τ2 (5.6–25.6) seconds suggesting the presence of diffusion-controlled and structural organization relaxation phenomena. The results demonstrate that natural films are a complex mixture of biomolecules covering a wide range of solubilities, surface activity and molecular mass with an apparent structural organization exhibiting a spatial and temporal variability.
Źródło:
Oceanologia; 2001, 43, 2
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Radar observation of wind farms in various weather conditions
Autorzy:
Stupak, T.
Świerczyński, S.
Wąż, M.
Powiązania:
https://bibliotekanauki.pl/articles/949946.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
marine radars
radar observation
radar
wind farms
weather condition
CARPET 2
ship position
ship position mark
Opis:
This article presents a calculation of condition detection wind farm by ship’s radar. The authors used computer programme CARPET 2 for simulation different propagation condition. Wind farm echoes are visible in significant distance and can be advantage to ship position mark.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2020, 14, 2; 325-329
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 marine diesel engines operating strategy
Autorzy:
Lus, T.
Powiązania:
https://bibliotekanauki.pl/articles/27315859.pdf
Data publikacji:
2018
Wydawca:
STE GROUP
Tematy:
marine diesel engines
planned maintenance
condition based maintenance
vibration analysis
Morskie silniki wysokoprężne
konserwacja planowa
wibracje
Opis:
Constant changes in the operating strategy of marine diesel engines are observed. They refer to whole engine and different functional systems of the engine in different range. The paper presents changes in marine diesel engines operating strategy. Gradual transition from simple failure response operating strategy - Corrective Maintenance (CM) to a reliability-oriented strategy - Reliability Centered Maintenance (RCM) has been described together with some remarks about Planed Maintenance (PM) systems and Condition Based Maintenance (CBM) systems with their latest form called CBM+. Some information about changes in diesel engines operating strategy in the Polish Navy (PN) at the turn of the last 35 years is also presented. An attempt to build engine analyzer for high-speed diesel engines at the Polish Naval Academy (PNA) in order to improve submarine diesel engines operating strategy is also described in the paper.
Źródło:
New Trends in Production Engineering; 2018, 1, 1; 739-746
2545-2843
Pojawia się w:
New Trends in Production Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Observations on relations between marine aerosol fluxes and surface-generated noise in the Southern Baltic Sea
Autorzy:
Markuszewski, P.
Klusek, Z.
Nilsson, E.D.
Petelski, T.
Powiązania:
https://bibliotekanauki.pl/articles/2079072.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
marine aerosol
aerosol flux
noise measurement
underwater noise
sea spray
hydroacoustic measurement
meteorological condition
Baltic Sea
Opis:
This study presents the preliminary results of combining underwater acoustic ambient noise measurements with those of in-situ sea spray fluxes (SSF). Hydroacoustic measurements (in the frequency range 80 Hz –12.5 kHz) were made using an underwater noise recording system developed at the Institute of Oceanology of the Polish Academy of Sciences which was then deployed in the southern Baltic Sea. The simultaneous measurements of coarse sea spray fluxes (with particle diameters ranging from 0.5 to 47 µm) were made on board the r/v Oceania using the gradient method. Observations were conducted for the duration of the passage of an atmospheric front that lasted 2.5 days (60 hours of measurements). There were significant differences in the sound pressure level (SPL) and aerosol fluxes observed between the first part of measurements (developing wave state) and the second part (developed waves). Wave parameters, such as peak period, significant wave height, wave age, and mean wave slope acquired from the WAM (WAve Model), were used to investigate the impact of wave field properties on noise and aerosol flux measurements. We observed different behaviours in the power spectrum density (PSD) levels of noise for these parameters depending on the wave state development.
Źródło:
Oceanologia; 2020, 62, 4PA; 413-427
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Assessment of mercury in muscles, liver and gills of marine and freshwater fish
Autorzy:
Luczynska, J.
Luczynski, M.J.
Paszczyk, B.
Powiązania:
https://bibliotekanauki.pl/articles/1189779.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Warmińsko-Mazurski w Olsztynie / Polskie Towarzystwo Magnezologiczne im. Prof. Juliana Aleksandrowicza
Tematy:
fish
total mercury
mercury
muscle
liver
gill
marine fish
freshwater fish
body weight
total length
biotic factor
condition factor
Opis:
In this study, the total mercury concentration was determined in the muscles, liver and gills of six fish species (rainbow trout Oncorhynchus mykiss Walb., carp Cyprinus carpio L., bream Abramis brama L., perch Perca fluviatilis L., ide Leuciscus idus L. and flounder Platichthys flesus L.). The fish were acquired from October to November 2012. Mercury was analyzed by atomic absorption spectrometry using thermal decomposition, compounds of mercury and amalgamation. The mercury content in fish organs reached 0.006-0.168 (in mg kgˉ¹ wet weight) in muscles, 0.001-0.027 in gills and 0.003-0.045 in the liver. The muscles of perch and ide had significantly more Hg compared to the other fish’s muscles (P≤0.05). The liver and gills of perch, ide and flounder contained more Hg than the same tissues of the other fish (P≤0.05). Generally, the highest Hg content was determined in muscles (except rainbow trout) (P≤0.05), whereas the lowest Hg content was found in gills (except perch) (P≤0.05). The content of Hg in gills of perch did not differ from the one in the liver (P>0.05). There was a positive correlation between the weight or length of a fish and the Hg concentration in its tissues, except for the length and Hg in the gills of carp. However, a statistically significant positive correlation between the body weight and the Hg levels in fish appeared only in the case of the organs of ide (P≤0.004) and muscles of carp (P≤0.038). The correlation between the factor condition and the content of Hg, albeit positive (0.106 < r < 0.811) except for the organs of flounder, was not statistically significant (P>0.05).
Źródło:
Journal of Elementology; 2016, 21, 1; 113-129
1644-2296
Pojawia się w:
Journal of Elementology
Dostawca treści:
Biblioteka Nauki
Artykuł

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