Preparation of Free-Surface Hyperbolic Water Vortices.

Free surface vortices are present in industry in flow regulation, energy dissipation, and energy generation. Although investigated extensively, detailed experimental data regarding free surface vortices are lacking, particularly regarding the turbulence at the interface. The present paper reports on a special type of free surface vortex first proposed by Walter Schauberger in the 1960s that has an oxygen volumetric mass transfer coefficient exceeding the value of similar systems.

Improving an existing proxy-based approach for floodplain denitrification assessment to facilitate decision making on restoration.

Excess nitrogen (N) from agricultural sources is a major contributor to the water pollution of rivers in Europe. Floodplains are of tremendous importance as they can permanently remove nitrate (NO) from the environment by releasing reactive N to the atmosphere in its gaseous forms (NO, N) during denitrification. However, the quantitative assessment of this ecosystem function is still challenging, particularly on the national level.

Investigation of the effect of sustainable magnetic treatment on the microbiological communities in drinking water.

The drinking water scarcity is posing a threat to mankind, hence better water quality management methods are required. Magnetic water treatment, which has been reported to improve aesthetic water quality and reduce scaling problems, can be an important addition to the traditional disinfectant dependent treatment. Despite the extensive market application opportunities, the effect of magnetic fields on (microbial) drinking water communities and subsequently the biostability is still largely unexplored, although the first patent was registered already 1945.

Density-dependent microbial calcium carbonate precipitation by drinking water bacteria via amino acid metabolism and biosorption.

Drinking water plumbing systems appear to be a unique environment for microorganisms as they contain few nutrients but a high mineral concentration. Interactions between mineral content and bacteria, such as microbial calcium carbonate precipitation (MCP) however, has not yet attracted too much attention in drinking water sector. This study aims to carefully examine MCP behavior of two drinking water bacteria species, which may potentially link scaling and biofouling processes in drinking water distribution systems.

Phylogeny of the Eurasian Wren Nannus troglodytes (Aves: Passeriformes: Troglodytidae) reveals deep and complex diversification patterns of Ibero-Maghrebian and Cyrenaican populations.

The Mediterranean Basin represents a Global Biodiversity Hotspot where many organisms show high inter- and intraspecific differentiation. Extant phylogeographic patterns of terrestrial circum-Mediterranean faunas were mainly shaped through Pleistocene range shifts and range fragmentations due to retreat into different glacial refugia. Thus, several extant Mediterranean bird species have diversified by surviving glaciations in different hospitable refugia and subsequently expanded their distribution ranges during the Holocene.

Electrically induced liquid-liquid phase transition in water at room temperature.

In this work we expand on findings previously reported [Wexler et al., Phys. Chem.

Behavioral study of selected microorganisms in an aqueous electrohydrodynamic liquid bridge.

An aqueous electrohydrodynamic (EHD) floating liquid bridge is a unique environment for studying the influence of protonic currents (mA cm) in strong DC electric fields (kV cm) on the behavior of microorganisms. It forms in between two beakers filled with water when high-voltage is applied to these beakers. We recently discovered that exposure to this bridge has a stimulating effect on .

Correction: Ecosystem Engineering by Plants on Wave-Exposed Intertidal Flats Is Governed by Relationships between Effect and Response Traits.

[This corrects the article DOI: 10.1371/journal.pone.

Non-equilibrium thermodynamics and collective vibrational modes of liquid water in an inhomogeneous electric field.

In this experiment liquid water is subject to an inhomogeneous electric field (∇(2)Ea≈ 10(10) V m(2)) using a high voltage (20 kV) point-plane electrode system. Using interferometry it was found that the application of a strong electric field gradient to water generates local changes in the refractive index of the liquid, polarizes the surface and creates a downward moving electro-convective jet. A maximum temperature difference of 1 °C is measured in the immediate vicinity of the point electrode.

A Quasi-Elastic Neutron Scattering Study of the Dynamics of Electrically Constrained Water.

We have measured the quasi-elastic neutron scattering (QENS) of an electrohydrodynamic liquid bridge formed between two beakers of pure water when a high voltage is applied, a setup allowing to investigate water under high-voltage without high currents. From this experiment two proton populations were distinguished: one consisting of protons strongly bound to oxygen atoms (immobile population, elastic component) and a second one of quasi-free protons (mobile population, inelastic component) both detected by QENS. The diffusion coefficient of the quasi-free protons was found to be D = (26 ± 10) × 10(-5) cm(2) s(-1) with a jump length lav ∼ 3 Å and an average residence time of τ0 = 0.

Ecosystem Engineering by Plants on Wave-Exposed Intertidal Flats Is Governed by Relationships between Effect and Response Traits.

In hydrodynamically stressful environments, some species--known as ecosystem engineers--are able to modify the environment for their own benefit. Little is known however, about the interaction between functional plant traits and ecosystem engineering. We studied the responses of Scirpus tabernaemontani and Scirpus maritimus to wave impact in full-scale flume experiments.

Identification and quantification of 16 inorganic ions in water by Gaussian curve fitting of near-infrared difference absorbance spectra.

This study shows two novel fitting strategies applied to differential absorbance spectra for identification and quantification of electrolytes. The effects of 16 dissolved salts were investigated in the wavelength range from 14000 to 9091 wavenumbers (714-1100 nm) by linear fits of the differential absorbance values (Y(υ,c)=offset(υ)+b(υ)×c) recorded for each wavenumber (υ) and concentration (c) ranges from 500 to 30 mM. The slopes (b) of these fits resulted in clear fingerprints of the electrolytes.

Effects of wind waves versus ship waves on tidal marsh plants: a flume study on different life stages of Scirpus maritimus.

Recent research indicates that many ecosystems, including intertidal marshes, follow the alternative stable states theory. This theory implies that thresholds of environmental factors can mark a limit between two opposing stable ecosystem states, e.g.

The preparation of electrohydrodynamic bridges from polar dielectric liquids.

Horizontal and vertical liquid bridges are simple and powerful tools for exploring the interaction of high intensity electric fields (8-20 kV/cm) and polar dielectric liquids. These bridges are unique from capillary bridges in that they exhibit extensibility beyond a few millimeters, have complex bi-directional mass transfer patterns, and emit non-Planck infrared radiation. A number of common solvents can form such bridges as well as low conductivity solutions and colloidal suspensions.

Ultrafast vibrational energy relaxation of the water bridge.

We report the energy relaxation of the OH stretch vibration of HDO molecules contained in an HDO:D(2)O water bridge using femtosecond mid-infrared pump-probe spectroscopy. We found that the vibrational lifetime is shorter (~630 ± 50 fs) than for HDO molecules in bulk HDO:D(2)O (~740 ± 40 fs). In contrast, the thermalization dynamics following the vibrational relaxation are much slower (~1.

Structural and immunological properties of arabinogalactan polysaccharides from pollen of timothy grass (Phleum pratense L.).

Extracts from pollen of timothy grass (Phleum pratense L.) contain up to 20% arabinogalactan proteins (AGPs). Separation of the AGP polysaccharide moieties by tryptic digestion, size exclusion chromatography (GPC), and reverse phase HPLC yielded arabinogalactan fractions AG-1 and AG-2 with molecular weights of approximately 15,000 and approximately 60,000Da, respectively.