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Tytuł:
Effect of saline water on the synergistic interaction between diesel and Triton X-100 in the flotation of oxidized coal
Autorzy:
Chang, Ziyong
Diallo, Lancine
Feng, Bo
Powiązania:
https://bibliotekanauki.pl/articles/1448948.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
saline water
surfactants
adsorption
flotation
coal oxidation
Opis:
In this study, the effect of medium saline water on the synergistic interaction between diesel and Triton X-100 in the flotation of oxidized coal was investigated. The results showed that the flotation yield of oxidized coal in saline water was higher than that in de-ionized (DI) water due to the promotion of diesel adsorption, which was attributed to the screening of electrostatic repulsion between diesel droplets and coal particles in saline water. Meanwhile, the flotation of oxidized coal could be significantly improved when Triton X-100 was added with diesel as a composite collector, and less Triton X-100 was required in saline water than that in DI water to achieve the same true flotation yield, indicating that saline water could increase the effectiveness of Triton X-100 in improving oxidized coal flotation. A mechanism study revealed that Triton X-100 was able to promote diesel adsorption on oxidized coal through emulsification, thus increasing the surface hydrophobicity of oxidized coal through hydrogen bonding between the headgroups of Triton X-100 and the oxygenated groups on coal surfaces. The non-ionic characteristic of Triton X-100 ensured its capability of enhancing oxidized coal flotation in both DI water and saline water.
Źródło:
Physicochemical Problems of Mineral Processing; 2021, 57, 1; 216-225
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of Mechanical Properties of Lightweight Concrete with Pumice Aggregate
Autorzy:
Shafiq, Malik Salman
Khan, Fasih Ahmed
Badrashi, Yasir Irfan
Khan, Fayaz Ahmed
Fahim, Muhammad
Abbas, Asim
Adil, Waqas
Powiązania:
https://bibliotekanauki.pl/articles/2024034.pdf
Data publikacji:
2021
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
lightweight concrete
pumice lightweight aggregate
saline water curing
Opis:
This paper presents the findings of a study carried out for evaluation of the mechanical behavior of lightweight concrete. Pumice, a rock resulting from cooling of lava, having entrapped air bubbles, has been used as a light- weight coarse aggregate. Evaluation of the mechanical behavior of the Pumice Lightweight Aggregate Concrete (PLWAC) has been carried out in comparison with the conventional concrete while comparing the mechanical properties of the two. Complete replacement of the coarse aggregate by volume had been carried out in the PLWAC. The testing regime consisted of conducting laboratory tests on concrete samples for evaluation of the mechanical properties including compressive strength, tensile stength, workability and dry density. It was concluded from the results that the use of lightweight aggregate resulted in a reduction in workability, as indicated by the slump test. Moreover, the dry density of PLWAC was also reduced by 30% as compared to the conventional concrete. A significant decrease (49%) in the compressive strength of PLWAC as compared to conventional concrete while a minor difference was observed in the tensile strenght of the two (2.9%). Based on the results of this study, it is recommended that PLWAC cannot be used in structures subjected to heavy loading conditions. However, PLWAC has a good potential to be used in low-cost structures with accompanying benefits of weight reduction.
Źródło:
Advances in Science and Technology. Research Journal; 2021, 15, 2; 30-38
2299-8624
Pojawia się w:
Advances in Science and Technology. Research Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wheat yield response and seasonal salt profile evolution under irrigation with saline waters in a semi-arid region
Autorzy:
Cheraghi, Seyed A. M.
Powiązania:
https://bibliotekanauki.pl/articles/293346.pdf
Data publikacji:
2020
Wydawca:
Instytut Technologiczno-Przyrodniczy
Tematy:
saline water
soil salinity
wheat yield
rainfall
leaching fraction
Opis:
Scarcity of fresh water resources is the major constraint for agricultural development in Iran as in many other regions with arid and semi-arid climate. With the pressure on fresh water resources, the use of un-conventional water resources including brackish, saline and sewage water has received greater attentions in recent years. The objective of this study was to assess the impact of farmers' practices using saline groundwater on wheat yield and soil salinity in a Mediterranean climate of Fars province in southern Iran. The study was carried out in several commercial wheat production regions for two years. Chemical analysis of irrigation waters, volume of applied irrigation water, electrical conductivity of soil saturation extract (ECe) and yield were measured in each field. General information on agronomic practices was also collected using a questionnaire. Results demonstrate that waters with salinities higher than what has been classified as “suitable for irrigation” are being used for the production of wheat crop. Analysis of wheat yield response to saline irrigation water showed that for water salinities up to 10.7 mS∙cm–1 (threshold value) variation in yield was relatively minor, above which wheat yield decreased at a greater rate. Root zone salinity profiles showed the effect of winter rainfall in reducing soil salinity. It is concluded that although acceptable yields are obtained with some of the highly brackish waters, over application of these waters would threaten the sustainability of crop production in the region.
Źródło:
Journal of Water and Land Development; 2020, 44; 26-32
1429-7426
2083-4535
Pojawia się w:
Journal of Water and Land Development
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Composite Barrier to Control the Corrosion of Mild Steel in Oil Well
Autorzy:
Singh, Rajesh Kumar
Thakur, Manjay Kumar
Kumar, Parshun
Powiązania:
https://bibliotekanauki.pl/articles/1030680.pdf
Data publikacji:
2020
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
HCl
Mild steel
Saline water
composite barrier
filler
thermal parameters
Opis:
Mild steel is a very important engineering metal. Petrochemical industries are used bulk amount for their various purposes like recovery of crude oil, refinery units and transportation. Crude oil is a very highly viscous liquid for the opening of the month well strong HCl acid and saline water is used. They produce hostile environment of mild steel. Gaseous substances like CO2 and SO2 gases are found into the well of petroleum. Large amount of saline water are used during recovery of crude oil in this water CO2 and SO2 are dissolved to produce H2CO3 and H2SO4. These acids create an acidic medium of mild steel. Saline waters have possessed Cl¯ ions. It produces ambient environment for mild steel. The solution of salty water contains dissolve oxygen which develop corrosive environment of mild steel. These major corrosive substances are available during recovery of crude oil and they form corrosion cell with base metal. Metal produces galvanic, pitting, stress, crevice, intergranular corrosion. Nanocaoting and filler methods are used to protect metal in such un-friendly environment. The corrosion rate of metal was calculated by weight loss experiment in absence and presence of nanocoating and filler materials. The synthesized organic compound octahydrodibenzo[a,d][8]annulene-5,12-dihydrazone is applied for nanocoating and MgS as filler. The coating and filling works were completed by chemical vapour deposition and nozzle spray method. Potentiostat used for determination corrosion potential and corrosion current density. The surface adsorption was studied by thermal parameters like activation energy, heat of adsorption, free energy, enthalpy and entropy. The thermal parameters results were shown that coating and filler compounds were adhered with base metal by chemical bonding. The thermal results were calculated by Arrhenius equation and Langmuir isotherm. The coating and the filler substance formed composite barrier with metal and developed a protective barrier for the corrosive substances.
Źródło:
World Scientific News; 2020, 139, 2; 155-172
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Assessment of Shoreline Changes and the Groundwater Quality along the Coast of Kuakata, Patuakhali, Bangladesh
Autorzy:
Goswami, Sukhen
Rahman, Shaikh Ashikur
Alam, Mir Md. Tasnim
Rahman, Mahfuzur
Rafiq, Md. Risalat
Jaman, Md. Hasnat
Roy, Dhiman Kumer
Powiązania:
https://bibliotekanauki.pl/articles/2173235.pdf
Data publikacji:
2022
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
saline water intrusion
hydrogeochemical analysis
digital shoreline analysis system
salinity
Opis:
Shoreline changes and groundwater quality monitoring have become pressing issues for the coastal region of Bangladesh. This study investigated the shoreline changes from 2000 to 2020 and evaluated the groundwater quality, as well as SWI in the Kuakata coastal area. While analyzing satellite images, the temporal shoreline changes were assessed through the Digital Shoreline Analysis System (DSAS) in ArcGIS 10.4.1. Higher erosion rates (>2 m/year) were found in the southernmost part and the SE part of the studied area. Twenty-five groundwater samples were collected, and the physicochemical parameters were measured to assess the groundwater quality. The geographic information system (GIS) was used to assess the spatial variation of the EC, pH, and Cl⁻ contents through the inverse distance weighted (IDW) interpolation method. The EC, Cl⁻, and pH values of the studied groundwater ranged from (1.2 mS/cm to 19.5 mS/cm), (79.88 mg/L to 11241.67 mg/L), and (7.9 to 8.7), repectively. The analysis revealed that the majority of the groundwater samples were unsuitable for drinking purpose due to higher EC and Cl⁻ values. Saline water intrusion (SWI) was determined by using the alternative EC vs Cl⁻ method in the southern part of the Kuakata beach area, which was closest to the sea.
Źródło:
Journal of Ecological Engineering; 2022, 23, 7; 323--332
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Large halocline variations in the Northern Baltic Proper and associated meso- and basin-scale processes
Autorzy:
Elken, J.
Malkki, P.
Alenius, P.
Stipa, T.
Powiązania:
https://bibliotekanauki.pl/articles/47628.pdf
Data publikacji:
2006
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
Sopot
current
splitting area
Finland Gulf
saline water
conference
Baltic Sea
halocline
Opis:
The Northern Baltic Proper is a splitting area of the Baltic Sea saline water route towards the two terminal basins – the Gulf of Finland and the Western Gotland Basin. Large halocline variations (vertical isopycnal displacements of more than 20 m, intra-halocline current speeds above 20 cm s−1) appear during and following SW wind events, which rapidly increase the water storage in the Gulf of Finland and reverse the standard estuarine transport, causing an outflow in the lower layers. In the channel of variable topography, basin-scale barotropic flow pulses are converted into baroclinic mesoscale motions such as jet currents, sub-surface eddies and lowfrequency waves. The associated dynamics is analysed by the results from a special mesoscale experiment, routine observations and numerical modelling.
Źródło:
Oceanologia; 2006, 48, S
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Możliwości zastosowania wskaźnika chlorkowo-bromkowego w identyfikacji zanieczyszczenia wód płynami po szczelinowaniu hydraulicznym
Possibilities of using chloride-bromide ratio in the identification of fracturing fluids contamination water
Autorzy:
Winid, B.
Powiązania:
https://bibliotekanauki.pl/articles/299117.pdf
Data publikacji:
2012
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
wskaźnik chlorkowo-bromkowy
zanieczyszczenie wód
wody zasolone
chloride-bromide ratio
contaminated water
saline water
Opis:
Jednym z problemów rozważanych w dyskusji na temat eksploatacji gazu łupkowego jest wpływ procesu szczelinowania hydraulicznego na stan środowiska wodnego. Wobec braku doświadczeń w tej dziedzinie musimy odwoływać się do prac i propozycji krajów, które już te działania podejmują. W pracy przeanalizowano możliwość zastosowania wskaźnika chlorkowo-bromkowego (równowagowego ilorazu zawartości jonów chlorkowych i bromkowych) do oceny stanu środowiska w aspekcie zanieczyszczenia płynami po szczelinowaniu hydraulicznym. Zwrócono uwagę na możliwości innych ognisk zanieczyszczeń, które mogą skutkować podobnym zakresem wartości tego wskaźnika, a także na niewielką ilość danych dotyczących wartości tego wskaźnika w wodach aktywnej strefy wymiany w warunkach Polski.
The impact of the hydraulic fracturing process on the water environment is one of the problems considered in the discussion on the exploiation of shale gas. In the absence of experience in this field we refer to the work and proposals for countries that already take these actions. The paper analyzes the possibility of using chloride-bromide ratio (the equilibrium ratio of chloride and bromide ion content) to assess the state of the environment in terms of contamination by hydraulic fracturing fluids. Attention was drawn to the possibility of other pollution sources, which may result in a similar range of values of this index. As well a small amount of data on the value of this ratio in the waters of an active exchange zone in the area of Poland.
Źródło:
AGH Drilling, Oil, Gas; 2012, 29, 1; 313-321
2299-4157
2300-7052
Pojawia się w:
AGH Drilling, Oil, Gas
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Variability in the saline water exchange between the Baltic and the Gulf of Gdańsk by the σ-coordinate model
Autorzy:
Jankowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/48078.pdf
Data publikacji:
2003
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
coastal zone
variability
thermohaline variability
water exchange
saline water
Baltic Sea
mass exchange
Gdansk Gulf
Opis:
A three-dimensional baroclinic σ–coordinate model was applied to study the circulation and thermohaline variability in the coastal zone in the south-eastern Baltic Sea. The model is based on the Princeton Ocean Model code of Blumberg & Mellor (1987), known as POM, and has the horizontal resolution of ∼5 km and 24 σ-levels in the vertical. The hydrodynamic conditions and variability of water and salt exchange between the Gulf of Gdańsk and the Baltic Proper, and the renewal of water masses in the Gulf of Gdańsk due to atmospheric forcing are analyzed. The numerical simulations were performed with real atmospheric forcings as well as with homogeneous (spatially uniform) wind fields over the whole Baltic Sea. The numerical simulations showed that the atmospheric forcing (winds) can play a significant role in shaping the renewal of bottom saline waters in the Gulf of Gdańsk. Two regions of inflow/outflow of saline waters responsible for the salinity regime were located. The overall water exchange between the Gulf and the Baltic Proper as well as the exchange of saline bottom waters appear to be strongly dependent on wind conditions. The net flux of water of salinity >9 PSU is of the order of 48 000–100000 m3 s−1. SE, E, S and NE winds were found to exert the greatest influence on salinity conditions in the Gulf of Gdańsk. Estimates of saline (salinity >9 PSU) water residence time based on the model simulation yielded values from 46 days for SE winds to 153 days for NW winds.
Źródło:
Oceanologia; 2003, 45, 1
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Impact of human-altered hydrographical setting on the copepod community structure in an extensive tropical estuary along the Southwest Coast of India
Autorzy:
Nagarathinam, A.
Retnamma, J.
Loganathan, J.
Singaram, P.
Arayillath, A.
Jose, A.K.
Powiązania:
https://bibliotekanauki.pl/articles/2079004.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
mesozooplankton
copepod
multivariate analysis
saline water
sea water intrusion
aquatic environment
tropical estuary
India coast
Opis:
This study presents how human-altered hydrographical settings (flow restrictions) impacts the natural distribution and community structure of copepods in the Kochi Backwaters (KBW), the largest monsoonal estuary along the southwest coast of India. This study is primarily based on an extensive seasonal sampling in the KBW and their comparison with a historical data set. Thannermukkom Barrage (TB) was built in the southern section of the KBW in the 1970s to prevent saline water intrusion to the upstream during the non-monsoon periods. Thirteen locations (1—4 in the downstream, 5—9 in the midstream, and 10—13 in the upstream) were sampled in this study over the entire stretch of the KBW during the Pre-Southwest Monsoon (PRM), Southwest Monsoon (SWM), and Post-Southwest Monsoon (PSWM). The overall effect of TB in the KBW is a seaward push of mesohaline conditions during all seasons with varying intensities. In response to the seaward push of mesohaline conditions, copepods Acartiella keralensis, Acartia plumosa, Acartia sp., Pseudodiaptomus annandalei, Pseudodiaptomus serricaudatus, Euterpina acutifrons and Oithona brevicornis showed a corresponding spatial shift for their highest abundance and diversity from midstream during PRM to the downstream during the SWM/PSWM. Multivariate and IndVal analysis demarcated many indicator species of copepods of different hydrographical settings in the KBW. A comparison with the historical data set showed that there is an apparent long-term change in hydrography, copepod composition and community structure in the upstream of the KBW due to TB.
Źródło:
Oceanologia; 2021, 63, 1; 115-132
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Potential Use of Saline Wastewater for the Agglomeration of Fluidized Fly Ash
Możliwość wykorzystania zasolonych wód odpadowych do aglomeracji popiołów lotnych
Autorzy:
Pertile, E.
Surovka, D.
Balcari, L.
Powiązania:
https://bibliotekanauki.pl/articles/317792.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Przeróbki Kopalin
Tematy:
wody zasolone
popioły lotne
dodatki do aglomeracji
saline water
CFBC fly ash
additivated granulate
Opis:
Experiments carried out within the research aimed to determine the influence of saline water on the properties of additivated granulate through interpreting extraction tests. Two types of mixing water of different degrees of mineralization were tested. Raw untreated water was used as a control sample. In assessing the potential use of saline water in the agglomeration of fluidized fly ash, aqueous extracts of fluidized-bed granulate mixed with water were subjected to analyses in accordance with valid legislation and standards. Based on the findings we identified their suitability for subsequent use. The main aim of the experiment was to compare the extraction test results of crushed and uncrushed granulate, which more or less fulfilled prerequisites of the intended testing. According to the obtained results it can be clearly seen that the mixing of salty water is recommended for use in the manufacture adducted granulate regardless of whether it is adducted granulate crushed or uncrushed, moistened raw untreated or salty water.
Eksperymenty przeprowadzone w ramach badań miały na celu określenie wpływu zasolenia wody na właściwości granulatu poprzez interpretację testów ekstrakcji. Zbadano dwa typy wody dodawanej do aglomeracji o różnym stopniu mineralizacji. Jako próbkę kontrolną użyto surową nieoczyszczoną wodę. Przy ocenie potencjalnego wykorzystania wody słonej w procesie aglomeracji lotnego popiołu fluidalnego, wodne ekstrakty z granulatu z popiołu fluidalnego zmieszanego z wodą zostały poddane analizom zgodnie z obowiązującymi przepisami i normami. Na podstawie ustaleń określono przydatność aglomeratów do późniejszego użycia. Głównym celem eksperymentu było porównanie wyników próby ekstrakcyjnej rozdrobnionego i nierozdrobnionego granulatu, które w mniejszym lub większym stopniu spełniły warunki zamierzonego badania. Zgodnie z uzyskanymi wynikami można wyraźnie zauważyć, że dodatek słonej wody jest zalecany do stosowania w wytwarzanym granulacie, niezależnie od tego, czy jest to granulat rozdrobniony czy nierozdrobniony, zwilżony, surową, nie poddaną obróbce lub słoną wodę.
Źródło:
Inżynieria Mineralna; 2018, R. 20, nr 2, 2; 273-280
1640-4920
Pojawia się w:
Inżynieria Mineralna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wheat water use and yield under different salinity of irrigation water
Zużycie wody i plon pszenicy w warunkach różnego zasolenia wody stosowanej do nawodnień
Autorzy:
Abedinpour, M.
Powiązania:
https://bibliotekanauki.pl/articles/292283.pdf
Data publikacji:
2017
Wydawca:
Instytut Technologiczno-Przyrodniczy
Tematy:
crop coefficient
saline water
stress
wheat crop
stres
uprawa pszenicy
woda słona
współczynnik roślinny
Opis:
A field experiment was conducted for determination of crop coefficient (KC) and water stress coefficient (Ks) for wheat crop under different salinity levels, during 2015–2016. Complete randomized block design of five treatments were considered, i.e., 0.51 dS∙m–1 (fresh water, FW) as a control treatment and other four saline water treatments (4, 6, 8 and 10 dS∙m–1), for S1, S2, S3 and S4 with three replications. The results revealed that the water consumed by plants during the different crop growth stages follows the order of FW > S1 > S2 > S3 > S4 salinity levels. According to the obtained results, the calculated values of KC significantly differed from values released by FAO paper No 56 for the crops. The Ks values clearly differ from one stage to another because the salt accumulation in the root zone causes to reduction of total soil water potential (Ψt), therefore, the average values of water stress coefficient (Ks) follows this order; FW(1.0) = S1(1.0) > S2(1.0) > S3(0.93) > S4(0.82). Precise data of crop coefficient, which is required for regional scale irrigation management is lacking in developing countries. Thus, the estimated values of crop coefficient under different variables are essential to achieve the best management practice (BMP) in agriculture.
W latach 2015–2016 przeprowadzono polowy eksperyment w celu określenia współczynnika roślinnego (KC) i współczynnika stresu (Ks) dla pszenicy nawadnianej wodą o różnym zasoleniu. Eksperyment przeprowadzono metodą bloków losowych w pięciu wariantach zasolenia: 0,51 dS∙m–1 (woda słodka FW jako kontrola) oraz 4, 6, 8 i 10 dS∙m–1 odpowiednio dla wariantów S1, S2, S3 i S4, każdy w trzech powtórzeniach. Wyniki wskazują, że woda pobierana przez rośliny w różnych stadiach ich rozwoju układała się w malejącym porządku zasolenia FW > S1 > S2 > S3 > S4. Obliczone wartości współczynnika KC różniły się istotnie od wartości podanych dla upraw w biuletynie FAO nr 56. Wartości Ks różniły się znacząco między poszczególnymi stadiami, ponieważ kumulacja soli w strefie korzeniowej ograniczyła całkowity potencjał wody glebowej (Ψt). Z tego powodu średnie wartości współczynnika stresu (Ks) malały w porządku FW(1,0) = S1(1,0) > S2(1,0) > S3(0,93) > S4(0,82). W krajach rozwijających się brakuje dokładnych danych o współczynniku roślinnym, które są niezbędne w regionalnym zarządzaniu wodą do nawodnień. Dlatego wartości współczynnika oznaczone w różnych wariantach zasolenia są istotne dla osiągnięcia najlepszych praktyk w gospodarce rolnej.
Źródło:
Journal of Water and Land Development; 2017, 33; 3-9
1429-7426
2083-4535
Pojawia się w:
Journal of Water and Land Development
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ wlewów z Morza Północnego do Morza Bałtyckiego na rozwój stada dorsza.
The impact of inflows from the North Sea to the Baltic Sea on the development of a cod stock.
Autorzy:
Wodzinowski, Tycjan
Radtke, Krzysztof
Nadolna-Ałtyn, Katarzyna
Szymanek, Lena
Witalis, Bartosz
Powiązania:
https://bibliotekanauki.pl/chapters/2118885.pdf
Data publikacji:
2016
Wydawca:
Morski Instytut Rybacki - Państwowy Instytut Badawczy
Tematy:
wlew słonych wód
Morze Bałtyckie
tarło dorsza
Baltic Sea
cod spawning
inflow of saline water
Opis:
Wlewy słonej wody z Morza Północnego są zjawiskiem o dużym znaczeniu dla Morza Bałtyckiego. Decydują o zmianie stosunków zasoleniowych i tlenowych, często także temperaturowych na obszarach i głębokościach zasiedlonych przez dorsza. Mogą wpływać na sukces reprodukcyjny ryb tego gatunku, nie są jednak jedynym czynnikiem wpływającym na sam proces reprodukcji. Porównując zapisy historyczne, widać, że od połowy lat 90. XX w. wlewy zaczęły być zjawiskami incydentalnymi. Brak wlewów prowadzi do utrwalenia pionowej stratyfikacji gęstościowej, a co za tym idzie – do stagnacji wody, szczególnie przy dnie, na głębokościach poniżej halokliny. W konsekwencji następuje zmniejszenie się zawartości rozpuszczonego tlenu w tej warstwie wód Morza Bałtyckiego. W obecnej chwili można stan taki uznać za sytuację normalną. Skutkiem stagnacji wody poniżej halokliny w dłuższym okresie jest zwiększenie się obszarów hipoksji, a nawet anoksji. Następstwem tego zjawiska jest zmniejszanie się zasięgu bytowania dorszy w Bałtyku, co w konsekwencji prowadzi do zagęszczenia stada i wzrostu konkurencji o pokarm, mających wpływ na kondycję ryb tego gatunku. W odniesieniu do postępu stagnacji wody nie bez znaczenia dla sukcesu rozrodczego dorszy jest również przesuwanie w czasie występowania szczytu tarła z maja i pierwszej połowy czerwca na koniec lipca i sierpień.
The inflows of saline water from the North Sea are a phenomenon of great importance to the Baltic Sea. They decide about the salinity and oxygen relations, often also about the temperature in the areas and depths inhabited by cod. They may affect the reproduction success of fish of this species, but they are not the only factor influencing the very process of reproduction. Comparing the historical records, it can be seen that since the mid-90s inflows began to be incidental phenomena. The lack of inflows leads to consolidation of the vertical density stratification, and thus the stagnation of water especially at the bottom at depths below the halocline. As a consequence, a reduction in the dissolved oxygen content in this layer of the Baltic Sea occurs. At the moment, such a state can be considered a normal situation. The stagnant water below the halocline in the long term results in the expansion of areas of hypoxia, or even anoxia. The consequence of this phenomenon is a limited range of cod distribution in the Baltic Sea, which in turn leads to the stock concentration in these areas and increased competition for food, affecting the condition of fish. With respect to the progress of water stagnation, shifting the time of the spawning peak from May and the first half of June to the end of July and August is not without significance for the reproduction success of cod.
Źródło:
95-lecie Morskiego Instytutu Rybackiego: aktualne tematy badań naukowych. Tom I. Zasoby ryb i rybołówstwo; 35-41
9788361650164
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Distinctive features of water exchange across the Słupsk Sill (a full-scale experiment)
Autorzy:
Paka, V.
Golenko, N.
Korzh, A.
Powiązania:
https://bibliotekanauki.pl/articles/47795.pdf
Data publikacji:
2006
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
Sopot
water exchange
thermohaline structure
Slupsk Sill
saline water
conference
Baltic Sea
high-resolution transect
inflow water
brackish water
Opis:
The flows of brackish waters in the upper layer and saline waters in the lower layer meet above the Słupsk Sill, which makes this one of the most significant features of the Baltic Sea, controlling as it does the ventilation of the deep basins in its central region. Earlier high-resolution measurements using towed scanning probes conducted here for more than ten years had revealed the complexity and variability of the water dynamics in this area. Mapping surveys repeated in quick succession are needed to study the water exchange in such an area. A survey of this kind was attempted in October 2003 during the 57th cruise of the r/v ‘Professor Shtokman’. Three surveys were carried out in the areas of the Słupsk Sill, the eastern Bornholm Basin, and the western Słupsk Furrow by means of a scanning probe towed along closely-spaced transects. The water structure around the sill was different each time, despite the rather short time gaps between the surveys. As follows from the data analysis, during the first survey, the saline Bornholm waters flowed over the sill as an axially symmetrical jet and entrained the adjacent freshened cold waters of the intermediate layer. In ten days, this joint flow displaced to the southern flank of the sill and propagated in the Słupsk Furrow along its southern border, with the dense core of saline waters gradually moving over the bottom to the northern border. Concurrently, the contrary flow of the main volume of cold freshened waters, originating from northern areas and leaving the Baltic Sea, was pushed away from the southern wall of the furrow and blocked at a significant distance from the sill. In three days, the blocked waters forced their way through towards its northern flank. Just below these waters, waters of elevated salinity were found above the eastern slope of the sill at the depth of its ridge, while waters of a similar salinity occurred below the depth of the ridge above the western slope of the sill. There were no indications of intensive overflow in the central and southern areas of the sill. Accordingly, the return flow of Bornholm waters across the sill became possible.
Źródło:
Oceanologia; 2006, 48, S
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the possibility of convective overturning in the Slupsk Furrow overflow of the Baltic Sea
Autorzy:
Zhurbas, V.
Elken, J.
Paka, V.
Piechura, J.
Chubarenko, I.
Vali, G.
Golenko, N.
Shchuka, S.
Powiązania:
https://bibliotekanauki.pl/articles/48298.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
Baltic Sea
deep water
dense water
density stratification
gravity current
numerical simulation
saline water
Slupsk Furrow
transverse circulation
water mass
Opis:
Closely spaced CTD transects across the Słupsk Furrow displayed a ‘downward- bending’ of salinity contours below the salinity interface on the southern flank due to a transverse circulation in the saline water overflow. Numerical simulation of a gravity current in an idealized channel with geometry, dimensions and initial density stratification all much the same as in the Słupsk Furrow was applied to verify whether the downward-bending could be transformed into an inverted density stratification. Some arguments in favour of the possibility of convective overturning due to the differential transverse advection beneath the gravity current, brought on by the numerical simulations, are discussed.
Źródło:
Oceanologia; 2011, 53, 3
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Restructuring of a zooplankton community by perturbation from a wind-forced coastal jet
Autorzy:
Pedersen, O.-P.
Tande, K.S.
Li, C.
Zhou, M.
Powiązania:
https://bibliotekanauki.pl/articles/47789.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
zooplankton
filament
intrusion
restructuring
mesoscale
perturbation
coastal region
Norway
transient wind
saline water
equivalent spherical diameter
Opis:
The impact of transient wind events on an established zooplankton community was observed during a field survey in a coastal region off northern Norway in May 2002. A transient wind event induced a coastal jet/filament intrusion of warm, saline water into our survey area where a semi-permanent eddy was present. There was an abrupt change in zooplankton community structure within 4–7 days of the wind event, with a change in the size structure, an increase in lower size classes less than 1 mm in equivalent spherical diameter (ESD) and a decrease in larger size classes greater than 1.5 mm in ESD. The slope of zooplankton biovolume spectra changed from −0.6 to −0.8, consistent with the size shifting towards smaller size classes. This study shows that even well established zooplankton communities are susceptible to restructuring during transient wind events, and in particular when wind forcing induces horizontal currents or filaments.
Źródło:
Oceanologia; 2010, 52, 3; 473-497
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
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