Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "level surface" wg kryterium: Temat

  Lista filtrów
Wyrównaj
Wyświetlanie 1-15 z 24
Tytuł:
On the reduction of geodetic and gravimetric measurements on technogenic and geodynamic polygons
Autorzy:
Perovych, Lev
Perovych, Igor
Gorlachuk, Valeriy
Powiązania:
https://bibliotekanauki.pl/articles/145497.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
przyspieszenie grawitacyjne
grawitacja
korekta
correction
gravitational acceleration
level surface
gravity reduction
Opis:
When conducting geodetic and gravimetric measurements, there is a problem of projecting them to the reference surface. Since the gravitational field is inhomogeneous under the real conditions, the problem arises of determining the corrections to the measured values of gravitational acceleration in order to use the obtained data for the subsequent solutions of projection problems. Currently, the solution to this problem is performed using a Bouguer reduction, which requires information about the internal structure of the upper layer of the earth’s surface, topography, etc. The purpose of this study is to develop a methodological approach that would allow to determine the reduction (projection) corrections for gravitational acceleration on technogenic and geodynamic polygons without using data about the distribution of surface layer density and topography. The research process is based on the use of mathematical analysis methods and a wide range of experimental geodetic and gravimetric measurements. In the course of the performed researches, an algorithm was obtained and a practical implementation of the determination of the corrections in the measured values of gravitational acceleration on the basis of geodetic and gravimetric measurements was carried out at the certain geodynamic polygon in order to bring all corrections to one level surface.
Źródło:
Geodesy and Cartography; 2020, 69, 1; 65-72
2080-6736
2300-2581
Pojawia się w:
Geodesy and Cartography
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spatial characteristics of water conductivity in the surface level of Polish arable soils
Autorzy:
Walczak, R
Ostrowski, J.
Witkowska-Walczak, B.
Slawinski, C.
Powiązania:
https://bibliotekanauki.pl/articles/26447.pdf
Data publikacji:
2002
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
surface level
Polska
water permeability
soil
water conductivity
water retention
arable soil
water balance
Źródło:
International Agrophysics; 2002, 16, 3
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Badania możliwości technicznych pomiaru płaskości powierzchni kinematyczną metodą trygonometryczną
Researches on technical possibilities of flatness examination using kinematic trigonometric method
Autorzy:
Wyczałek, I.
Plichta, A.
Wyczałek, M.
Powiązania:
https://bibliotekanauki.pl/articles/371964.pdf
Data publikacji:
2017
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
płaskość
poziom powierzchni
tachimetr zmotoryzowany
pomiar kinematyczny
flatness
motorized tachymeter
surface level
kinematic measurement
Opis:
Nowe podejście do pomiaru płaskości posadzek lub innych powierzchni poziomych bazuje na użyciu sensorów montowanych na pojeździe przemieszczającym się po tych powierzchniach w mniej lub bardziej zautomatyzowany sposób. Staje się ono konkurencyjne w stosunku do metod klasycznych wykorzystujących łatę i klin lub pochyłomierze przykładane w miejscu pomiaru, a także do stosowanych zamiennie metod geodezyjnych. Pomiar z użyciem pojazdów wymaga z jednej strony przemieszczania sensorów wzdłuż zadanych linii, z drugiej - odpowiedniej częstości i precyzji odczytów. Prowadzone są prace badawczo-wdrożeniowe nad wykonywaniem kinematycznych pomiarów tachimetrycznych do pryzmatu przemieszczanego na posadzce. Prace te obejmują dwa aspekty: zdolność pomiarową instrumentów oraz precyzję oceny płaskości w funkcji przemieszczania pryzmatu w określonych kierunkach na badanej powierzchni. Tematy te stanowią przedmiot prac naukowo-badawczych i są okresowo publikowane. W ramach niniejszej pracy wykonano próby kinematycznego pomiaru zmotoryzowanym tachimetrem (RTS) Leica TCRP 1201+ do pryzmatu przemieszczanego na zdalnie sterowanym pojeździe stosowanym w modelarstwie i robotyce. Opracowano modele pomiaru (różne warianty skanowania), poddano analizie wiarygodność reprezentacji osi pomiarowej przez uśrednianie między dwoma kołami pojazdu oraz wykonano testy mające na celu stwierdzenie poprawności pomiaru wykorzystanym typem tachimetru do poruszającego się celu. Testowano oba warianty skanowania: (i) wzdłuż zadanych linii oraz (ii) wzdłuż dowolnie dobranych linii, uzyskując zbliżone wyniki (nieprzekraczające 10%). W efekcie przeprowadzonych badań uznano, że przyjęte tezy znajdują potwierdzenie a tym samym stwierdzono, że zastosowane podejście może być stosowane do pomiarów płaskości posadzek.
The new approach for measuring the flatness of floors or other horizontal surfaces is based on the use of vehicle-mounted sensors that moves through these surfaces in a more or less automated way. It becomes competitive in relation to the classical methods using the straightedge and the wedge or tilts or geodetic methods used interchangeably. The measurement with vehicles requires, on the one hand, the movement of the sensors along the set lines, and on the other - the appropriate frequency and precision of the readings. Research and implementation works on the implementation of kinematic tacheometric measurements to the prism moved on the floor are still underway. These works cover two aspects: the measurement capability of the instruments and the precision of evaluation of flatness as a function of prism movement in certain directions on the tested area. These topics are the subject of scientific research and are periodically published. As the part of this work, kinematic measurements of the Leica TCRP 1201+motorized tacheometer (RTS) have been performed to the prism mounted on a remote-controlled vehicle used in modeling and robotics. Measurement models (different scan variants) were developed, the reliability of the measurement axes' position by averaging between two wheels of the vehicle was analyzed, and tests that enabled determination of the accuracy of the totalizer-type measurement for the moving target were performed. Both scan variants were tested: (i) along fixed lines and (ii) along individually defined lines, obtaining comparable results (not exceeding 10%). As a result of the research, it was concluded that the adopted theses were confirmed and thus the applied approach could be used for measuring flatness of the floor.
Źródło:
Zeszyty Naukowe. Inżynieria Środowiska / Uniwersytet Zielonogórski; 2017, 165 (45); 49-65
1895-7323
Pojawia się w:
Zeszyty Naukowe. Inżynieria Środowiska / Uniwersytet Zielonogórski
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Monitoring surface contamination for thirty antineoplastic drugs: a new proposal for surface exposure levels (SELs)
Autorzy:
Dugheri, Stefano
Mucci, Nicola
Bucaletti, Elisabetta
Squillaci, Donato
Cappelli, Giovanni
Trevisani, Lucia
Bonari, Alessandro
Cecchi, Michele
Mini, Enrico
Ghiori, Andrea
Tognoni, Daniela
Berti, Nicola
Alderighi, Francesca
Li Vigni, Nicola
Orlandi, Irene
Arcangeli, Giulio
Powiązania:
https://bibliotekanauki.pl/articles/2152946.pdf
Data publikacji:
2022
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
health risk assessment
antineoplastic drugs
wipe test
ultra-high performance liquid chromatography
surface exposure level
tandem mass spectrometry
Opis:
Background Chemotherapy drugs are widely used to treat cancer, but their active compounds represent a danger for workers who could be exposed to them. However, they aren’t yet included in directive CE No. 1272/2008 and the European Biosafety Network has only recommended a limit value of 100 pg/cm2 for surface contamination. Thus, it is crucial to assess surface contaminations in healthcare environments. Currently, the technique of choice is surface wipe test combined with liquid chromatography tandem mass spectrometry to achieve high sensibility. Material and Methods A campaign involving Careggi University Hospital (Florence, Italy) was performed from January 2020 to December 2021, collecting 1449 wipe samples between administration units, preparation unit, and personnel gloves. From the obtained data, the 90th percentile was calculated for 30 antiblastic drugs and proposed as surface exposure levels (SELs); while from data concerning personnel glove contamination, weekly contamination was estimated. Results In the 2-year period only 417 wipe samples were found positive (28.8%), the majority of which regard samples coming from administration unit bathrooms. The proposed SELs are almost all <100 pg/cm2, except for few drugs which produce higher contamination on bathroom surfaces. Also, the estimation of pharmacy personnel’s glove contamination highlighted very low results (ng/week). Conclusions Deeply established protocols and procedures for safe handling of ADs allow for obtaining excellent cleaning results and thus a safer work environment, however, the risk of cytostatic contaminations cannot be avoided in healthcare workplaces, and thus a harmonization of classification and labeling of chemotherapy drugs throughout the European Union should be done.
Źródło:
Medycyna Pracy; 2022, 73, 5; 383-396
0465-5893
2353-1339
Pojawia się w:
Medycyna Pracy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Water relations during two hydrological years in swampy areas in the Siemianice Forest Experimental Station
Autorzy:
Krysztofiak, A.T.
Miler, A.T.
Powiązania:
https://bibliotekanauki.pl/articles/62494.pdf
Data publikacji:
2008
Wydawca:
Polska Akademia Nauk. Stowarzyszenie Infrastruktura i Ekologia Terenów Wiejskich PAN
Tematy:
water relation
hydrology
swamp area
Siemianice Forest Experimental Station
forest experimental station
ground water level
surface water level
climate change
Marianka Forest District
forest environment
water resource
water condition
Opis:
In recent years researchers have focused increasingly on climatic changes taking place in nature (increasing air temperature, decreasing precipitation totals). These imply changes in components of water balances and in practice changes in water relations both on the global and local scale. At present site overdrying is considered to be the biggest threat [Pierzgalski 2007]. The aim of the study is to present water relations in the forest swampy areas in a forest district (the Marianka Forest District) of the Siemianice Forest Experimental Station in hydrological years of 2005 and 2006. The investigations showed that analysed catchments, despite being located in swampy areas, are characterized by periods of water depletion in ditches. In analysed watercourses runoff was recorded from mid-November 2004 to the beginning of June 2005, while in the next hydrological year it was recorded again from mid-November, but this time longer to mid-June 2006. In relation to ground water of the catchment area a predictable relationship was observed of the water table level at the locations of observation wells. The wells located in the top sections of the catchment had water table the deepest below the ground level, while wells in valleys had water tables at the most shallow levels. It may also be stated that wells situated in higher areas (watershed), are characterized by a slightly bigger variation in the ground water table during the year than it was the case with wells located at lower points (in valleys). Both analyzed hydrological years (2005 and 2006) showed a similar pattern of ground water table at individual sites. Moreover, a marked cyclicity was recorded in the elevation of the water table, i.e. water level rising in autumn and lowering in summer months (as a result of changes in plant transpiration). The relationship of ground water levels with different forest sites found in the analyzed catchments confirms the dependence on the site moisture level variant. Water was lying at the most shallow levels in the ash-alder swamp forest site – a marshy site, while it was markedly the deepest in fresh mixed coniferous forest sites – a fresh site type. When analyzing changes in the ground water levels in terms of stand age classes we may clearly observe the seasonal variation and similar patterns of changes. Water lay the most shallow in stands of age classes V and VI. The level was significantly deepest in age class IV. The above dependencies pertained both to the hydrological year 2005 and 2006.
Źródło:
Infrastruktura i Ekologia Terenów Wiejskich; 2008, 06
1732-5587
Pojawia się w:
Infrastruktura i Ekologia Terenów Wiejskich
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Extreme sea levels at selected stations on the Baltic Sea coast
Autorzy:
Wolski, T.
Wisniewski, B.
Giza, A.
Kowalewska-Kalkowska, H.
Boman, H.
Grabbi-Kaiv, S.
Hammarklint, T.
Holfort, J.
Lydeikaite, Z.
Powiązania:
https://bibliotekanauki.pl/articles/47831.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
Baltic Sea
Baltic coast
sea level
storm surge
fall
sea surface
surface deformation
wind speed
wind stress
Źródło:
Oceanologia; 2014, 56, 2
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Topological Fragmentation of Medical 3D Surface Mesh Models for Multi-Hierarchy Anatomical Classification
Autorzy:
Zwettler, G. A.
Backfrieder, W.
Powiązania:
https://bibliotekanauki.pl/articles/226172.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
3D surface mesh
functional classification in medicine
multi-hierarchy classification
level of detail
spline-based surface selection
Opis:
High resolution 3D mesh representations of patient anatomy with appendant functional classification are of high importance in the field of clinical education and therapy planning. Thereby, classification is not always possible directly from patient morphology, thus necessitating tool support. In this work a hierarchical mesh data model for multi-hierarchy anatomical classification is introduced, allowing labeling of a patient model according to various medical taxonomies. The classification regions are thereby specified utilizing a spline representation to be placed and deformed by a medical expert at low effort. Furthermore, application of randomized dilation allows conversion of the specified regions on the surface into fragmented and closed sub-meshes, comprising the entire anatomical structure. As proof of concept, the semi-automated classification method is implemented for VTK library and visualization of the multihierarchy anatomical model is validated with OpenGL, successfully extracting sub-meshes of the brain lobes and preparing classification regions according to Brodmann area taxonomy.
Źródło:
International Journal of Electronics and Telecommunications; 2015, 61, 2; 129-136
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of global climate oscillations on intermonthly to interannual variability of sea levels along the English Channel Coasts (NW France)
Autorzy:
Turki, I.
Massei, N.
Laignel, B.
Shafiei, H.
Powiązania:
https://bibliotekanauki.pl/articles/2079277.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
sea level
interannual variability
storm
atmospheric circulation
climatic oscillation
sea surface temperature
sea level pressure
North Atlantic oscillation
English Channel
Opis:
This work examines the multiscale variability in sea level along the English Channel coasts (NW France) using a wavelet multiresolution decomposition of water level values and climate oscillations in order to gain insights in the connection between the global atmospheric circulation and the local-scale variability of the monthly extreme surges. Changes in surges have exhibited different oscillatory components from the intermonthly (~3–6-months) to the interannual scales (~1.5-years, ~2–4-years, ~5–8-years) with mean explained variances of ~40% and ~25% of the total variability respectively. The correlation between the multiresolution components of surges and 28 exceptional stormy events with different intensities has revealed that energetic events are manifested at all timescales while moderate events are limited to short scales. By considering the two hypotheses of (1) the physical mechanisms of the atmospheric circulation change according to the timescales and (2) their connection with the local variability improves the prediction of the extremes, the multiscale components of the monthly extreme surges have been investigated using four different climate oscillations (Sea Surface Temperature (SST), Sea-Level Pressure (SLP), Zonal Wind (ZW), and North Atlantic Oscillation (NAO)); results show statistically significant correlations with ~3–6-months, ~1.5-years, ~2–4-years, and ~5–8-years, respectively. Such physical links, from global to local scales, have been considered to model the multiscale monthly extreme surges using a time-dependent Generalized Extreme Value (GEV) distribution. The incorporation of the climate information in the GEV parameters has considerably improved the fitting of the different timescales of surges with an explained variance higher than 30%. This improvement exhibits their nonlinear relationship with the large-scale atmospheric circulation.
Źródło:
Oceanologia; 2020, 62, 2; 226-242
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new approach for simultaneous shape and topology optimization based on dynamic implicit surface function
Autorzy:
Guo, H.
Zhao, K.
Wang, M. Y.
Powiązania:
https://bibliotekanauki.pl/articles/970141.pdf
Data publikacji:
2005
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
optymalizacja topologiczna
pochodna topologiczna
topology optimization
implicit
surface function
topological derivative
level set
Opis:
In the present paper, a new approach for structural topology optimization based on dynamic implicit surface function (DISF) is proposed. DISF is used to describe the shape/topology of a structure, which is approximated in terms of the nodal values. Then, a relationship is established between the element stiffness and the values of the implicit surface function on its four nodes. In this way and with some non-local treatments of the design sensitivities, not only the shape derivative but also the topological derivative of the optimal design can be incorporated in the numerical algorithm in a unified way. Numerical experiments demonstrate that by employing this approach, the computational efforts associated with DISF (and level set) based algorithms can be diminished. Clear optimal topologies and smooth structural boundaries free from any sign of numerical instability can be obtained simultaneously and efficiently.
Źródło:
Control and Cybernetics; 2005, 34, 1; 255-282
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Recharge and drainage of lakes in the Powidzki Landscape Park in conditions of increased anthropogenic and environmental pressure (central-western Poland)
Autorzy:
Nowak, Bogumił Michał
Przybyłek, Jan
Powiązania:
https://bibliotekanauki.pl/articles/2058553.pdf
Data publikacji:
2020
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
surface resources
groundwater resources
hydraulic contacts
water level changes
mining dewatering
evapotranspiration
Gniezno Lakeland
Opis:
The lakes of the Powidzki Landscape Park (Gniezno Lakeland) are known for their natural and recreational values. The majority of them are located within two large glacial tunnel valleys, that in many places cut through several levels of till and inter-till aquifers. Regional hydraulic linkage systems are developed where surface water and groundwater remain in direct contact. Smaller water bodies occur between the lakes, in other tunnel valleys, in isolated meltwater basins, or in river valleys. These water bodies constitute local drainage bases. The existence in the area of such morphologically diverse lakes with different flow rates, varied morphology, and heterogeneous geological structure permitted tracing of the hydrodynamic dependencies of lake catchments of various types. Hydrogeological cross-sections, comparative analyses of structural maps for successive aquifers, bathymetric plans of lakes, and piezometric contour maps were prepared. Surface and groundwater level fluctuations were investigated, as well as their response to changing atmospheric conditions. Water balances of lakes were also determined for selected lake catchments. The study showed that all the lakes analysed are closely related to groundwater, and that the deepest ones reach lower aquifers. The majority of the lakes drain the aquifers, but some of the lakes feed them. Such a situation was documented in coastal wetlands and in the eastern part of the Park, affected by a depression cone associated with a nearby lignite opencast mine. The study showed that the deepest of the lakes analysed have a very wide catchment area of groundwater recharge, expanding beyond the boundaries of their surface catchment areas. This is important for the development of their resources, especially in periods of hydrogeological low flow.
Źródło:
Geological Quarterly; 2020, 64, 1; 205--219
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Shoulder girdle muscle activity and fatigue during automobile chassis repair
Autorzy:
Tian, Baozhen
Yu, Suihuai
Chu, Jianjie
Li, Wenhua
Powiązania:
https://bibliotekanauki.pl/articles/2161964.pdf
Data publikacji:
2019-07-15
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
muscle activity
surface electromyography
muscle fatigue
perceived level of discomfort
automobile chassis repair
shoulder postures
Opis:
Objectives The objective of this study was to assess the postures that were commonly used in automobile chassis repair operations, and to evaluate shoulder girdle muscle fatigue for different combinations of the weight of hand-tools. Material and Methods Two right muscles, including upper trapezius (UT) and middle deltoid (MD), were selected. Surface electromyography (SEMG) and a perceived level of discomfort (PLD) were used to assess the degree of shoulder girdle fatigue. Fifteen healthy young male subjects from the Northwestern Polytechnical University participated in the test. The test consisted of assuming 4 different postures and maintaining each of them for 60 s. The 4 postures varied in terms of dumbbell weights, standing for the hand-tools weight: W1 was 0.48 kg and W2 was 0.75 kg; the 4 shoulder postures were shoulder flexions of 150°, 120°, 90°, and 60°, combined with an included elbow angle of 180°, 150°, 120° and 90°, respectively. The experimental sequences were randomly selected. The signals of SEMG and the values of PLD in the shoulder girdle were recorded in 60 s. All subjects completed the whole test. The repeated measure analysis of variance (ANOVA) was performed to ascertain differences between dumbbell weight (0.48 kg and 0.75 kg) and shoulder postures (150°/180°, 120°/150°, 90°/120° and 60°/90°). The Friedman test was utilized to determine the significant differences for UT(PLD) and MD(PLD) on shoulder postures. Spearman’s correlation was used to analyze the relationship between the subjective and objective measurements. Results Significant correlational relationships existed between the UT percentage of the maximal voluntary electrical activation (%MVE) and UT(PLD) (r = 0.459, p < 0.01), between MD(%MVE) and MD(PLD) (r = 0.821, p < 0.01). The results showed that SEMG and PLD of the 4 postures under analysis differed significantly (p < 0.05). Conclusions It was indicated that posture T4 (shoulder forward flexion 60° and included elbow angle 90°) resulted in the lowest fatigue, both in terms of the objective measure and the subjective perception, which meant that this posture was more ergonomic. Int J Occup Med Environ Health. 2019;32(4):537–52
Źródło:
International Journal of Occupational Medicine and Environmental Health; 2019, 32, 4; 537-552
1232-1087
1896-494X
Pojawia się w:
International Journal of Occupational Medicine and Environmental Health
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Temporal Patterns of Quality Surface Water Changes
Autorzy:
Mitryasova, Olena
Pohrebennyk, Volodymyr
Salamon, Ivan
Oleksiuk, Alina
Mats, Andrii
Powiązania:
https://bibliotekanauki.pl/articles/1839615.pdf
Data publikacji:
2021
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
surface water quality
water security
hydrochemical indicators
level of pollution
resistance degree of pollution
Inhulets river
Opis:
The dynamics of hydrochemical parameters of surface waters from the upper, middle and lower reaches of the river was analyzed. On the basis of the analysis of temporal and spatial monitoring data, a comprehensive assessment of the environmental status of the Inhulets river (Ukraine) waters by hydrochemical indicators was carried out. The study performed a comparative analysis of the river water quality assessment using different methods: an integrated assessment based on the calculation of water pollution indexes, pollution rate. A result of the evaluation of water quality in certain classes: in terms of ammonium ions and BOD5 – III quality class, the water is slightly polluted; phosphate content – V quality class, water is very low in the bottom; according to the content of suspended solids, in phosphates and BOD5 – III class of water quality, water is polluted; by a concentration of chlorides – V class of quality, degree of purity – very dirty; the value of suspended solids and chlorides – III class; in terms of the sulfate content – IV class. In general, the very excessive concentration of substances in the middle course remains stable, the environmental state is poor (quality class IV).
Źródło:
Journal of Ecological Engineering; 2021, 22, 4; 283-295
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Microplankton size structure induced by a warm-core eddy in the Western Bay of Bengal: Role of Trichodesmium abundance
Autorzy:
Chinnadurai, K.
Retnamma, J.
Nagarathinam, A.
Subramanian, P.R.
Singaram, P.
Shoba, S.
Powiązania:
https://bibliotekanauki.pl/articles/2078908.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
microplankton
size structure
biomass
Trichodesmium
sea surface temperature
wind
sea level
geostrophic current circulation
chlorophyll a
Bengal Bay
Opis:
Mesoscale warm-core eddies are common in the Bay of Bengal (BoB), and this study in the western BoB during Pre-Southwest Monsoon (April 2015) presents how a prolonged warmcore core eddy could modify the microplankton biomass and size structure. To investigate this, field sampling and laboratory analyses were augmented with satellite data sets of sea surface temperature (SST), winds, mean sea level anomaly (MSLA), geostrophic currents and chlorophyll-a. High SST with positive MSLA (≥ 20 cm) and a clockwise circulation, represented the occurrence of a large warm-core eddy in the western BoB. Time series data evidenced that it was originated in the mid of March and persistent there till early June, which in turn caused a decrease in the surface nutrients and chlorophyll-a. The abundance and biomass of microplankton were negligible in the warm-core eddy region. FlowCAM data showed a significant decrease in the autotrophic microplankton parameters in the warm-core eddy (av. 13 ± 9 ind. L−1 and 0.1 ± 0.04 μgC L−1, respectively) as compared to the surrounding locations (av. 227 ± 143 ind. L−1 and 0.8 ± 0.5 μgC L−1, respectively). Low nutrients level in the warm core eddy region favoured high abundance of needle-shaped phytoplankton cells dominated by Trichodesmium cells. As a result, the size of micro-autotrophs in the warm-core eddy was larger (av. 91,760 ± 12,902 μm3 ind.−1) than its outside (av. 50,115 ± 21,578 μm3 ind.−1). This is a deviation from our belief that the oligotrophy decreases the phytoplankton size. We showed here that the above understanding might not be infallible in warm-core eddies in the northern Indian Ocean due to its inducing effect on the Trichodesmium abundance.
Źródło:
Oceanologia; 2021, 63, 3; 283-300
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Propagation of Upwelling on Western-Coast Sumatra During Madden-Julian Oscillation Event
Autorzy:
Haryanto, Y. D.
Fitrianti, N.
Hartoko, A.
Anggoro, S.
Zainuri, M.
Powiązania:
https://bibliotekanauki.pl/articles/125091.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
MJO
upwelling
coastal upwelling
coastal downwelling
mean sea level pressure
potential velocity
zonal wind
meridional wind
sea surface temperature
Opis:
Madden-Julian oscillation (MJO) is an atmospheric oscillation due to atmospheric phenomenon that occurs due to the uniformity of solar energy received at the surface of the earth, MJO is a natural occurrence in the seaatmosphere system. When the MJO is active, in general there will be a disturbance in the upper air which is then followed by an anomaly at sea surface pressure causing the changes in the wind on the surface. The changes in the surface wind affect the sea surface currents which then cause the occurrence of coastal upwelling downwelling. The upwelling process itself is a process whereby a sea mass is pushed upward along the continent, when the beach is to the left of the wind direction, the ecological transport leads to the mass of water away from the coast. As a result, there is a mass vacuum (divergence) in the coastal area. This mass void will be filled by the mass of water from the inner layer that moves to the surface. Indonesian territory itself is passed by MJO in phases 3, 4 and 5, while for Sumatra region is passed by MJO phase 3 and 4. This research aims to identify the propagation of coastal upwelling during MJO on the west coast of Sumatera, therefore the data of geopotential height, surface pressure sea ( MSLP), zonal and meridional components and sea surface temperature are used to analyze how the MJO effect on the coastal upwelling occurs in the research area. The analysis was conducted in June, July and August by comparing the atmospheric conditions at the time of strong MJO in phases 3 and 4 with normal viewing of anomaly geopotential height and MSLP and then seeing the anomaly surface wind changes from zonal wind (u) and meridional wind (v) and changes in SST in Sumatra region. The result shows that there is a change of GH and MSLP when MJO passes the west coast of Sumatra and then follows the change in the value of u and v and SST to identify the upwelling, while the anomaly change negative SST does not occur when MJO is active but has time lag (lag). In this analysis it was found that SST anomaly occurs when the anomaly changes in both the upper and surface water occurring after 5 days in phases 3, 4 and 5.
Źródło:
Journal of Ecological Engineering; 2018, 19, 1; 122-128
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Development of the sandy coast: Hydrodynamic and morphodynamic conditions (on the example of the Eastern Gulf of Finland)
Autorzy:
Divinsky, B.V.
Ryabchuk, D.V.
Kosyan, R.D.
Sergeev, A.Y.
Powiązania:
https://bibliotekanauki.pl/articles/2078924.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
sandy coast
coastal zone
climate change
hydrodynamic condition
morphodynamic condition
sea level
surface wave
sediment transport
numerical modelling
Finland Gulf
Opis:
Forecasting the coastal zone development under possible climatic changes and technogenic impact is an extremely important task. This forecasting is based on our understanding of the mechanism of the hydrodynamic processes impact on the coastal zone. The goal of this work is to describe the hydrodynamic conditions (currents, sea level, surface waves) of coastal waters and to assess the influence of hydrodynamic parameters on the general dynamics of the beach. The object of this study is a part of the southern coastal zone of the Gulf of Finland (Baltic Sea). The method of research is a full-scale experiment and mathematical modeling. The initial data for the analysis are climatic characteristics of the hydrodynamic regime of the sea (velocity and direction of currents, sea level, integral parameters of wind seas and swell), as well as interannual variations in the position of the coastline in the region of the Izhora village in the eastern part of the Gulf of Finland. Interannual variations in hydrodynamic parameters and volumes of bottom material transported under the influence of wind seas and swell were estimated. Main conclusion: swell waves determine the general background in the patterns of the bottom material transport, and the contribution of wind seas is in the formation of beach properties, namely, the accumulation or decrease of beach material
Źródło:
Oceanologia; 2021, 63, 2; 214-226
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 24

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies