scholarly journals Integrated Ecohydrological Models in Aquatic Ecosystems

Water ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 204
Author(s):  
Naicheng Wu ◽  
Yixia Wang ◽  
Yaochun Wang ◽  
Qinghua Cai ◽  
Wei Ouyang

As a critical component of the global environment, aquatic ecosystems support a wide range of organisms, including bacteria, fungi, algae, invertebrates, plants, and fish [...]

Axioms ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 44
Author(s):  
Gana Gecheva ◽  
Miroslav Hristov ◽  
Diana Nedelcheva ◽  
Margarita Ruseva ◽  
Boyan Zlatanov

We have obtained a new class of ordered pairs of multivalued maps that have pairs of coupled fixed points. We illustrate the main result with two examples that cover a wide range of models. We apply the main result in models in duopoly markets to get a market equilibrium and in aquatic ecosystems, also to get an equilibrium.


Author(s):  
Shu-Ying Tseng ◽  
Po-Yu Liu ◽  
Yi-Hsuan Lee ◽  
Zong-Yen Wu ◽  
Chiu-Chen Huang ◽  
...  

Shewanella algaeis a rod-shaped Gram-negative marine bacterium frequently found in nonhuman sources such as aquatic ecosystems and has been shown to be the pathogenic agent in various clinical cases due to the ingestion of raw seafood. The results of this study showed thatS. algaewas present in approximately one in four samples, including water and shellfish samples. Positive reactions (API systems) inS. algaestrains were seen for gelatinase (gelatin); however, negative reactions were found for indole production (tryptophan).S. algaeis adapted to a wide range of temperatures (4°C, 25°C, 37°C, and 42°C) and salinity. Temperature is a key parameter in the pathogenicity ofS. algaeas it appears to induce hemolysis at 25°C and 37°C.S. algaeexhibits pathogenic characteristics at widely varying temperatures, which suggests that it may have the ability to adapt to climate change.


Author(s):  
Adriana Veríssimo Serrão

The author seeks in this chapter to contribute to the deepening of the philosophy of landscape, an area of philosophy still in constitution, paying special attention to the ethical dimension. If the ethics of nature have deep roots in the great systems of idealism and romanticism, and if environmental ethics was most recently formed in the 1980s, offering solutions to the crisis of nature, a landscape-specific ethic did not merit still a sufficiently distinctive theoretical treatment. Some previous notes favor the need for this differentiation. Landscape, as it encompasses a wide range of intersections and interrelationships between various levels of reality—from natural to intervened or highly artificial landscapes—cannot be analytically extracted from nature. Landscape, as a differentiating concept, multiplied by unlimited world configurations, cannot be extracted from the (global) environment because, since each landscape is an individuality, its existence is always local.


2020 ◽  
Vol 12 (10) ◽  
pp. 4070
Author(s):  
Matej Biček ◽  
Raphaël Connes ◽  
Senad Omerović ◽  
Aydin Gündüz ◽  
Robert Kunc ◽  
...  

In-wheel motors offer a promising solution for novel drivetrain architectures of future electric vehicles that could penetrate into the automotive industry by transferring the drive directly inside the wheels. The available literature mainly deals with the optimization of electromagnetically active parts; however, the mechanical design of electromagnetically passive parts that indirectly influence motor performance also require detailed analysis and extensive validation. To meet the optimal performance of an in-wheel motor, the mechanical design requires optimization of housing elements, thermal management, mechanical tolerancing and hub bearing selection. All of the mentioned factors have an indirect influence on the electromagnetic performance of the IWM and sustainability; therefore, the following paper identifies the hub bearing as a critical component for the in-wheel motor application. Acting loads are reviewed and their effect on component deformation is studied via analytically and numerically determined stiffness as well as later validated by measurements on the component and assembly level to ensure deformation envelope and functionality within a wide range of operations.


2016 ◽  
Vol 1 (1) ◽  
pp. 28-37
Author(s):  
Mohd Nasarudin Harith ◽  
Ruhana Hassan

A study was carried out to evaluate the diversity and similarity of cyanobacterial populations in selected Sarawak aquatic ecosystem using β-indices. Eight stations including aquaculture ponds, cage cultures, waterfall and artificial lake located in Serian, Bau and Batang Ai areas were selected. A total of 43 species belonging to 30 genera of cyanobacteria were recorded. The most distributed pattern among all sampling stations belongs to the genera Chroococcus, Lyngbya, Nostoc and Oscillatoria. The highest β diversity values were found among non-contiguous stations. Besides, no identical or totally different cyanobacteria diversity values were obtained among those non-contiguous stations. The highest β diversity value (0.84) was found among stations with contrasting environmental characteristics. The wide range of β-diversity and similarity suggested that different locations and types of aquatic ecosystems may have variations in physico-chemical properties of the water and eventually lead to the different composition of cyanobacteria.


Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3442
Author(s):  
Maxime Sorriaux ◽  
Mathias Sorieul ◽  
Yi Chen

Water contamination resulting from human activities leads to the deterioration of aquatic ecosystems. This restrains the access to fresh water, which is the leading cause of mortality worldwide. In this work, we developed a bio-based and water-resistant composite aerogel from renewable nanofibrils for water remediation application. The composite aerogel consists of two types of cross-linked nanofibrils. Poly(dopamine)-coated cellulose nanofibrils and amyloid protein nanofibrils are forming a double networked crosslinked via periodate oxidation. The resulting aerogel exhibits good mechanical strength and high pollutants adsorption capability. Removal of dyes (rhodamine blue, acriflavine, crystal violet, malachite green, acid fuchsin and methyl orange), organic traces (atrazine, bisphenol A, and ibuprofen) and heavy metal ions (Pb(II) and Cu(II)) from water was successfully demonstrated with the composite aerogel. More specifically, the bio-based aerogel demonstrated good adsorption efficiencies for crystal violet (93.1% in 30 min), bisphenol A (91.7% in 5 min) and Pb(II) ions (94.7% in 5 min), respectively. Furthermore, the adsorption–desorption performance of aerogel for Pb(II) ions demonstrates that the aerogel has a high reusability as maintains satisfactory removal performances. The results suggest that this type of robust and bio-based composite aerogel is a promising adsorbent to decontaminate water from a wide range of pollutants in a sustainable and efficient way.


2021 ◽  
Vol 3 (1) ◽  
pp. 54-60
Author(s):  
Didem Gökçe

The quick improvement of nanotechnology permits a wide range of utilization of engineered nanoparticles, such as personal care products, medicals, optics, electronics, and automobiles. The nanoparticles manufactured from Ag, Au carbon-nanotube, ZnO, SiO2, TiO2, Cu, Ni, and magnetic ferrites are among the generally utilized in products. The nanoparticles are produced and utilized in large quantities and release into marine and freshwater ecosystems during production, use, discharge, treatment, and deposition. Those particles with a mean size of 1 nm - 100 nm are of potential environmental risks because of their particular qualifications and high reactivity although their great economical values. Based on the studies, the size, shape, and surface physical and chemical characteristics of the nanoparticles show the level of aggregation, solubility, structural and chemical composition, the importance of the use of nanoparticles, and their toxicity with biological systems. Nanoparticles can potentially cause adverse impacts on tissue, cellular, genetic materials, and protein- enzyme levels due to their unique physical and chemical qualifications. In this study, the effects of nanoparticles on aquatic organisms and aquatic ecosystems were evaluated.


1990 ◽  
Vol 22 (5) ◽  
pp. 107-111 ◽  
Author(s):  
M. B. Vojinović ◽  
S. T. Pavkov ◽  
D. D. Buzarov

In this paper, the concentration of a wide range of persistent organochlo-rine compounds α, β,γ, hexachlorocyclohexane Ʃ-HCH, p,p 'DDE, o,p 'DDE, p,p 'DDT and polychlorinated biphenyls (PCBs) in the aquatic environments of the river Danube, Tisa, Lake Palić, and fish-pond Ečka are reported. The residues of organochlorine insecticides -OCI and PCBs in water, sediments, fish muscle and eggs of aquatic birds were analysed. These data show the serious contamination of selected aquatic ecosystems (Danube, Tisa, Lake Palić and fish-pond Ečka) of Vojvodina. Because of the concentration of these compounds at top levels, fish, eggs of aquatic birds and sediments are an excellent indicator for detecting trace organic compounds whose presence in water would be difficult to measure directly. The residues of OCI were determined by GC-ECD. Polychlorinated biphenyls -- PCB congeners were quantified by high-resolution gas chromatography (HRGC-ECD).


2020 ◽  
Vol 44 (2) ◽  
pp. 155-170 ◽  
Author(s):  
Olivier N Lemaire ◽  
Vincent Méjean ◽  
Chantal Iobbi-Nivol

ABSTRACT The Gram-negative Shewanella bacterial genus currently includes about 70 species of mostly aquatic γ­-proteobacteria, which were isolated around the globe in a multitude of environments such as surface freshwater and the deepest marine trenches. Their survival in such a wide range of ecological niches is due to their impressive physiological and respiratory versatility. Some strains are among the organisms with the highest number of respiratory systems, depending on a complex and rich metabolic network. Implicated in the recycling of organic and inorganic matter, they are important components of organism-rich oxic/anoxic interfaces, but they also belong to the microflora of a broad group of eukaryotes from metazoans to green algae. Examples of long-term biological interactions like mutualism or pathogeny have been described, although molecular determinants of such symbioses are still poorly understood. Some of these bacteria are key organisms for various biotechnological applications, especially the bioremediation of hydrocarbons and metallic pollutants. The natural ability of these prokaryotes to thrive and detoxify deleterious compounds explains their use in wastewater treatment, their use in energy generation by microbial fuel cells and their importance for resilience of aquatic ecosystems.


2021 ◽  
Author(s):  
Joni Dehaspe ◽  
Andreas Musolff

<p>Nitrate (NO<sub>3</sub><sup>-</sup>) and phosphate (PO<sub>4</sub><sup>3-</sup>) inputs to rivers are high in Germany and Europe following energy and food production demands, which can cause harm to aquatic ecosystems and jeopardize drinking water supplies. It is known that permanent and non-permanent nutrient uptake can retain significant amounts of NO<sub>3</sub><sup>-</sup> and PO<sub>4</sub><sup>3-</sup> in river networks, however, there is little knowledge about the mechanistic processes involved and their controlling factors on catchment scales. In this work we apply a data driven analysis using the shape of stable, multi-annual, low frequency concentration-discharge (C-Q) relationships in about 500 German monitoring stations. More specifically, the bending of NO<sub>3</sub><sup>-</sup> C-Q relationship was shown to encode uptake efficiency. We systematically address the effects of light and shading, stream ecological status, land-use, hydrological conditions, stream network configurations and chlorophyll a patterns as potential in-stream processing predictors. This assessment allows us to conclude on dominant controls of NO<sub>3</sub><sup>-</sup> uptake efficiency across a wide range of landscape types.</p>


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