Search results for "WATER"
showing 10 items of 9348 documents
Trace elements in thermomineral waters in Greece
2020
Trace elements have a fundamental role in natural and anthropogenic systems. In waters, they present a great variability of concentrations that mostly depends on the degree of gas-water-rock interactions and geochemical conditions such as pH, temperature, redox and/or exchange reactions, etc. Even though, they are present in very low contents in host-rocks, elevated concentrations in ground or surface waters may have a hazardous impact on human health and thus, it is important to both quantify and understand their behavior in natural systems. Here we present the results of about 300 cold and thermal mineral waters collected along the entire Hellenic territory. Physicochemical parameters (te…
Konfigurowanie granic gatunkowych a problem polityczności. Przypadek posthumanizmu i transhumanizmu
2017
Przedmiotem artykułu są teoriopolityczne rozważania na temat posthumanizmu. Jest to podejście, które zrywa z humanistycznym dogmatem, że człowiek jest bytem najważniejszym w rzeczywistości. Zamiast tego posthumanizm dowartościowuje byty pozaludzkie (naturalne, sztuczne, rzeczy), z którymi ludzie wchodzą w rozmaite interakcje. Autor uznał, że problematyka posthumanistyczna może być rozpatrywana w perspektywie biopolityki, która zajmuje się relacjami między polityką a życiem. Jednakże w odróżnieniu od wcześniejszych ujęć wiążących biopolitykę z kontrolą populacji posthumanizm stawia na szali żywotność gatunkową. W artykule przedstawiono konsekwencje takiego myślenia dla problemu polityczności…
Upper thermal threshold of Lepidurus arcticus (Branchiopoda, Notostraca) in lakes on the southern outreach of its distribution range
2021
Qvenild T, Fjeld E, Fjellheim A, Hammar J, Hesthagen T and Lakka H-K. 2021. Upper thermal threshold of Lepidurus arcticus (Branchiopoda, Notostraca) in lakes on the southern outreach of its distribution range. Fauna norvegica 41: 50–88. The Arctic tadpole shrimp Lepidurus arcticus has a circumpolar distribution and the Scandes (Fennoscandian Mountains) marks its southernmost limit in Europe. Within this area, 391 natural and 88 regulated lakes with L. arcticus have been identified, of which 87% are above the treeline. The lakes hosting L. arcticus decrease in altitude from south to north, which results from its temperature preferences. The majority of the locations are at a lower lake air t…
Acid–base properties of functionalised tripodal polyamines and their interaction with nucleotides and nucleic acids
2010
Novel, highly positively charged tripodal polyamines with appended heterocyclic moieties revealed an intriguing panel of protonation species within the biologically relevant range. Studied compounds bind nucleotide monophosphates by mostly electrostatic interactions but only the imidazole analogue showed selectivity toward UMP in respect to other nucleotides. Strong binding of all the studied compounds to both ds-DNA and ds-RNA is to some extent selective toward the latter, showing rather rare RNA over DNA preference.
In-depth characterization of denitrifier communities across different soil ecosystems in the tundra
2022
Abstract Background In contrast to earlier assumptions, there is now mounting evidence for the role of tundra soils as important sources of the greenhouse gas nitrous oxide (N2O). However, the microorganisms involved in the cycling of N2O in this system remain largely uncharacterized. Since tundra soils are variable sources and sinks of N2O, we aimed at investigating differences in community structure across different soil ecosystems in the tundra. Results We analysed 1.4 Tb of metagenomic data from soils in northern Finland covering a range of ecosystems from dry upland soils to water-logged fens and obtained 796 manually binned and curated metagenome-assembled genomes (MAGs). We then sear…
Effect of the submerged vegetation distribution on flow characteristics and lateral dispersion: Experimental analysis at the apex section of a meande…
2020
Understanding of how the vegetation distribution influences flow patterns and turbulence structure is extremely important to analyse environmental processes as the sediment transport and the mixing of transported quantities. In the present paper attention is focused on the effect of flexible vegetation on flow characteristics and dispersion processes at the apex section of a large-amplitude meandering bend. The analysis is conducted with the aid of data collected in a laboratory meandering flume both in the absence of vegetation on the bed and in the presence of real and flexible vegetation on the bed. Results show that the presence of vegetation affects both the lateral dispersion coeffici…
Siracusa: carte tematiche di analisi. Patrimonio culturale. Interazioni tra patrimonio costiero, servizi e attività culturali e domanda di cultura. F…
2008
Siracusa: carte tematiche di analisi. Patrimonio culturale. Interazioni tra patrimonio costiero, servizi e attività culturali e domanda di cultura. Feste e percorsi del sacro. Contesto 1, 2, 3, 4, 5. Definizione dei contesti, analisi dei rischi, rilevamento dei bisogni e delle aspettative. Buone pratiche: valutazioni e indirizzi per la promozione e la valorizzazione culturale dei waterfront
Pulsed flow-through cultivation of Margaritifera margaritifera : effects of water source and food quantity on the survival and growth of juveniles
2020
AbstractConservation of the endangered freshwater pearl mussel (FPM) includes artificially rearing juveniles, but the pulsed flow-through (PFT) method, enabling the continuous renewal of water and food in culture containers, has not been applied to FPM. This study tested the PFT method in culture of FPM juveniles, and the effect of water source (tap vs well water) and food concentration (mixture of commercial phytoplankton products) on the survival and growth of juveniles. Beaker-specific survival rates varied from 0 to 100% (mean: 34%) and from 0 to 58% (mean: 16%) in the 1st (2-week) and 2nd (10-week) experiment, respectively. In the 1st experiment, juveniles attained statistically signif…
Adaptive Control of Underactuated Underwater Vehicles
2008
This paper deals with a control strategy for underactuated underwater vehicles whose target is trajectory tracking. A cascade approach is employed which brings to a control law consisting of: a) an outer loop, obtained from the vehicle kinematic model, which forces this model to track the reference trajectory; b) an inner adaptive control loop which forces the system to track the reference signals given by the outer control loop. Conditions for asymptotic tracking of the trajectory and boundness of the unactuated velocities are given. Simulation tests illustrate the proposed approach.
A Computationally Efficient Online/Offline Signature Scheme for Underwater Wireless Sensor Networks
2022
Underwater wireless sensor networks (UWSNs) have emerged as the most widely used wireless network infrastructure in many applications. Sensing nodes are frequently deployed in hostile aquatic environments in order to collect data on resources that are severely limited in terms of transmission time and bandwidth. Since underwater information is very sensitive and unique, the authentication of users is very important to access the data and information. UWSNs have unique communication and computation needs that are not met by the existing digital signature techniques. As a result, a lightweight signature scheme is required to meet the communication and computation requirements. In this researc…