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Compares methane metabolism and diversity of organisms that oxidized atmospheric methane in different soil samples by radioactive labelling. Regulation of atmospheric concentrations by microbial oxidation; Characterization of methanotrophic bacteria by phospholipid ester-linked fatty acids (PLFA) analysis; Conventional analysis of microbial PLGA.

Studies the metabolism of atmospheric methane in a forest soil by radiotracer techniques. Assimilation of the oxidized atmospheric methane; Recovery of the remaining methane; Maintenance of the carbon conversion efficiency; Increase of overall methane oxidation activity; Effect of methane starvation and physical disturbance.

Cathode ray tube (CRT) panel glass is processed into glass foams by using carbon and Mn 3 O 4 as foaming agents. We investigate the foaming ability and foaming mechanism of the mixture by varying the composition and the temperature. Carbon load of 5 wt% inhibits the sintering of the glass powder, while 2 wt% carbon promotes the coalescence of pores during foaming. Carbon load of ≤0.4 wt% is suitable for achieving low density foams (0.15–0.23 g cm-3) with closed pores (75–100%). Foaming is initiated by the reaction between carbon and Mn 3 O 4 and this is the main source of melt expansion. Reduction of cations in the glass melt, including Mn3+ dissolved from Mn 3 O 4 , makes an important contribution to the melt foaming at >800 °C. The main gaseous product is CO 2 (67–95 vol%). CO appears above 800 °C and the concentration increases with temperature. [ABSTRACT FROM AUTHOR]

The process of foaming glass is very dependent on the chemical composition of the glass. In this study we used a foaming-agent/oxidizing-agent couple and a crystallization inhibitor to foam cullets of flat, container and CRT-panel glass. Foamed glass with a density of 110–120 kg m –3 , a thermal conductivity of 50–52 mW m –1 K –1 and a homogeneous pore structure was obtained from a mixture of panel glass, 0.33 wt% carbon and 4.45 wt% Fe 2 O 3 . We also showed that it is possible to fabricate foamed glass with the same density or pore structure as mentioned above by adding up to 50 wt% container cullet or 70 wt% flat glass to the mixture. In the foamed samples with a low content of panel glass, crystals form, resulting in an increased open porosity, density and inhomogeneous pore structure. The crystallization can, however, be inhibited by adding calcium phosphate, so enabling the preparation of high-quality foamed glass from flat glass or flat/container-glass mixture. The pore gas is predominantly CO 2 and the pressure inside the pores is 0.36–0.47 bar. The reduced effect of the composition on the foaming process suggests that there is a great potential for stabilizing the production of foamed glass and ensuring the product's quality. [ABSTRACT FROM AUTHOR]

• Mixture of glass powder and water glass is atmosphere sensitive. • Reaction with CO 2 results in the formation of carbonates. • Newly formed carbonates are the main source of expansion gas (CO 2). • New mechanism of foaming with water glass proposed. Water glass is a common additive in the process of direct foaming of glass, however, the currently accepted foaming mechanism lacks experimental validation. A foaming mixture of waste cathode ray tube panel glass and water glass was investigated for its expansion and gas evolution behavior via hot stage microscopy and thermogravimetry coupled with mass spectroscopy, respectively. The evolution of a significant amount of CO 2 during the heating of the foaming mixture was detected and an overwhelming presence of CO 2 within the pores of the foamed glass was confirmed with gas chromatography. With this investigation, we reveal an underlying foaming mechanism, where a carbonate phase forms after mixing water glass with the glass powder and later acts as the foaming agent. The unveiled mechanism could help further research in the field of foamed glass, with the potential to produce more sustainable materials with better performance via less energy-demanding processes. [ABSTRACT FROM AUTHOR]

Abstract: Oxidation of atmospheric methane by soil methanotrophs is a microbial process highly susceptible to physical and chemical disturbances. In this study, atmospheric methane oxidation activity in soil samples from beech (Fagus sylvatica) and spruce (Picea abies) forest stands decreased significantly after physical disturbance and/or increased exposure to ambient air. This activity loss was oxygen dependent, but independent of the presence of atmospheric methane. However, methanotrophic activity in forest soil was stabilized by amendment with various sorbents including activated charcoal, aminopropylsilane, and gamma aluminum oxide (γ-Al2O3). γ-AlO3 at a concentration >1% (g g−1) was found to stabilize and sometimes stimulate oxidation of atmospheric methane in soil from both beech and spruce forest stands. γ-Al2O3 amendment also stimulated atmospheric methane oxidation in advective flow-based soil biofilters, and the filter efficiency was found to increase with time. In both soil samples and soil biofilters, elevated oxidation of atmospheric methane was sustained for >100 days. γ-Al2O3 likely immobilized potentially inhibitory soil constituents including inorganic nitrogen and soil organics. The results of the study indicated that: 1) decreases in atmospheric methane oxidation activity in topsoil after soil homogenization and/or increased air exposure was likely related to increased bioavailability of inhibitory substances; 2) indigenous inhibitory compounds are present in topsoil in both beech and spruce forest soil; and 3) oxidation of atmospheric methane in soil can be restored and sometimes stimulated by immobilizing inhibitory compounds using γ-Al2O3 as sorbent. [Copyright &y& Elsevier]

A new microarray method, the isotope array approach, for identifying microorganisms which consume a [sup 14]C-labeled substrate within complex microbial communities was developed. Experiments were performed with a small microarray consisting of oligonucleotide probes targeting the 16S rRNA of ammonia-oxidizing bacteria (AOB). Total RNA was extracted from a pure culture of Nitrosomonas eutropha grown in the presence of [[sup 14]C]bicarbonate. After fluorescence labeling of the RNA and microarray hybridization, scanning of all probe spots for fluorescence and radioactivity revealed that specific signals were obtained and that the incorporation of [sup 14]C into rRNA could be detected unambiguously. Subsequently, we were able to demonstrate the suitability of the isotope array approach for monitoring community composition and CO[sub 2] fixation activity of AOB in two nitrifying activated-sludge samples which were incubated with [[sup 14]C]bicarbonate for up to 26 h. AOB community structure in the activated-sludge samples, as predicted by the microarray hybridization pattern, was confirmed by quantitative fluorescence in situ hybridization (FISH) and comparative amoA sequence analyses. CO[sub 2] fixation activities of the AOB populations within the complex activated-sludge communities were detectable on the microarray by [sup 14]C incorporation and were confirmed independently by combining FISH and microautoradiography. AOB rRNA from activated sludge incubated with radioactive bicarbonate in the presence of allylthiourea as an inhibitor of AOB activity showed no incorporation of [sup 14]C and thus was not detectable on the radioactivity scans of the microarray. These results suggest that the isotope array can be used in a PCR-independent manner to exploit the high parallelism and discriminatory power of microarrays for the direct identification of microorganisms which consume a specific substrate in the environment. [ABSTRACT FROM AUTHOR]

Analyzes the methane concentrations along the salinity profiles in nine tidal estuaries in Europe. Surface water concentrations; Global estuarine flux of methane to the atmosphere; Median water-air methane gradient.

• Foaming couples for foaming CRT panel glass in air and argon atmosphere. • Best foaming effect in air achieved with MnO 2 , open-porous foam. • Beneficiary role of oxidizing agent on foaming in oxygen-free atmosphere revealed. • Best foaming effect in argon with carbon black and Mn 3 O 4 , closed-porous foam. • Pore-gas analyzed as in major part CO 2. We report on the use of foaming agent couples to foam cathode-ray-tube panel glass and uncover the influence of the carbon type, Mn x O y and furnace atmosphere on the foaming effect and physical properties of the foams. In oxidizing atmosphere, carbon burns out before the foaming starts and the best foaming effect is achieved with MnO 2. The samples are open porous and thermal conductivity is 47 mW m–1 K–1 at 161 kg m–3. In oxygen-free atmosphere, oxidation of carbon is facilitated by Mn 3 O 4 as an oxidizing agent. Activated carbon with a high reactivity leads to the formation of CO and open porosity. Thermal conductivity of the closed-porous sample with CO 2 in the pores, produced with carbon black and Mn 3 O 4 , reaches 50 mW m–1 K–1 at 204 kg m–3 and exhibits the highest potential for improving the thermal insulation further by decreasing the density. [ABSTRACT FROM AUTHOR]

In Denmark, American mink (Neovison vison) have been bred for their fur since the mid-1920s. Mink escaping from farms may supply the feral population. Often, it is of biological and management interest to separate the population of feral mink (i.e. mink caught in the wild) in two groups: 1) mink born on farms i.e., escapees, and 2) mink born in the wild. In this study, two methods were used for separating feral mink into the two groups: a) Comparison of body length of farmed mink and feral mink, and b) Presence of a biomarker (tetracycline: an oral antibiotic used on mink farms). A total of 367 wild caught mink (from the mainland of Denmark and the island of Bornholm), and 147 mink from farms, collected during the period 2014–2018, were used for the analysis of body length. For the testing of tetracycline (TC) as a biomarker, 78 mink from farms where there was knowledge about TC treatment (with or without) were examined for fluorescent markings in the canine teeth. Results from both univariate analyses and Gaussian mixture model analysis demonstrated clear divisions between the mean body length (mean ± S.E., range) of farmed males (52.1 cm ± 0.4, 48–68) and farmed females (mean 44.0 ± 0.2, 40–50), and between farmed mink and wild caught mink. Mixture analysis identified two groups within each sex of the wild caught mink, one assigned to farmed mink (born in captivity) and another group of smaller mink suspected of being born in the wild. On Bornholm, the mean (±SD, range) length of males born in the wild was 43.7cm (± 0.3, 36–57) and for females 37.5cm (± 0.3, 32–45). The mean length (±SD, range) of males born in the wild in the mainland of Denmark was 42.5cm (± 2.3, 36–46) and for females 36.1cm (± 1.0, 34–37). Among the feral mink from mainland Denmark, 28.4% of males and 21.6% of females were identified as escapees, while 0% of the males and 1% of the females were identified as escapees among the wild caught mink on Bornholm. Eight percent of mink from farms using tetracycline were false negatives, while no false positives were found among mink from farms not using TC. TC fluorescence was found in five of 217 mink caught in the wild equivalent to 22% escapees in mainland Denmark. No TC markings were found in mink caught in the wild on Bornholm. In conclusion, both methods a) the body length of mink, and b) fluorescent biomarkers in canine teeth are considered as useful tools to identifing mink that have escaped from farms. [ABSTRACT FROM AUTHOR]

Extensive physiological analyses of different microbial community members in many samples are difficult because of the restricted number of target populations that can be investigated in reasonable time by standard substrate-mediated isotope-labeling techniques. The diversity and ecophysiology of Rhodocyclales in activated sludge from a full-scale wastewater treatment plant were analyzed following a holistic strategy based on the isotope array approach, which allows for a parallel functional probing of different phylogenetic groups. Initial diagnostic microarray, comparative 16S rRNA gene sequence, and quantitative fluorescence in situ hybridization surveys indicated the presence of a diverse community, consisting of an estimated number of 27 operational taxonomic units that grouped in at least seven main Rhodocyclales lineages. Substrate utilization profiles of probe-defined populations were determined by radioactive isotope array analysis and microautoradiography-fluorescence in situ hybridization of activated sludge samples that were briefly exposed to different substrates under oxic and anoxic, nitrate-reducing conditions. Most detected Rhodocyclales groups were actively involved in nitrogen transformation, but varied in their consumption of propionate, butyrate, or toluene, and thus in their ability to use different carbon sources in activated sludge. This indicates that the functional redundancy of nitrate reduction and the functional versatility of substrate usage are important factors governing niche overlap and differentiation of diverse Rhodocyclales members in this activated sludge. [ABSTRACT FROM AUTHOR]

• Development of low-density open- and closed-porous foamed glasses. • Homogeneous pore structure with >90% of open or closed pores. • Open porosity achieved by partial crystallization of the glass. • Low thermal conductivity (37.5–65.6 mW m−1 K−1) measured using heat-flow meter. • Analysis of the difference in the thermal conductivity. Future developments in foamed glass should focus on improving the thermal insulation properties, controlling the foamed structure and the type of porosity. In this study, we report on the synthesis and properties of foamed glasses with open-porous and closed-porous structures prepared from waste cathode-ray-tube (CRT) panel and soda-lime-silica glasses with the addition of carbon black, and manganese or iron oxides. The samples exhibit a homogeneous structure with an average pore size in the range 0.5–1.35 mm and open porosity above 91% or closed porosity above 92%. The open porosity was obtained by partial crystallization of the glass during the foaming process. The thermal conductivity, measured using a heat flow meter at 10 °C, is 57.2–65.6 mW m−1 K−1 at 116–143 kg m−3 for the open-porous samples and 37.5–56.2 mW m−1 K−1 at 107–245 kg m−3 for the closed-porous samples. The conduction in the solid phase contributes the major part to the effective thermal conductivity (52–72%). The conduction in the gaseous and solid phases, respectively, is higher in the open-porous foamed glass due to the different gas composition (air) and the different solid composition (glass composition and crystalline content). The developed foamed glasses also have high mechanical strength, making them suitable for load-bearing applications. [ABSTRACT FROM AUTHOR]