VEGETATION SYNTAXONOMY AND LAND MANAGEMENT EFFECT ON METHANE AND CARBON DIOXIDE EMISSIONS FROM WETLANDS: A CASE STUDY FROM TIDAL SALT AND BRACKISH MARSH

Carbon dioxide (CO 2 ) and methane (CH 4 ) emission from wetlands significantly contribute to climate change andglobal warming. The interaction between among vegetation type, various environmental factors, andmanagement regimes such as grazing and mowing is considered important in the calculation of CO 2 and CH 4 gasflux for an ecosystem. In this study, vegetation composition, CH 4 and CO 2 flux, soil characteristics, airtemperature and humidity from the brackish marsh and salt marsh wetland ecosystems on Terschelling Islandin Northern Holland were measured. We aimed to investigate the relationship between vegetation composition, grazing, and mowing on CH 4 and CO 2 emission. The abundance and number of plant species werehigher in brackish than in salt marsh. Grazing was found to influence species richness, 39 species being found ina grazed site of brackish marsh compared to 31 species in a similar ungrazed site. CO 2 fluxes in salt and brackishmarsh were found to be similar while CH 4 flux in the salt marsh was found to be lower than in the brackishmarsh. Within the brackish marsh, a higher methane emission was recorded in the grazed zone. However theoverall effect of grazing and mowing was found to be negligible for CH 4 flux but is suggested to clearly reduceCO 2 flux in both the salt and brackish marsh

Biomimetic strategies to produce catalytically reactive CuS nanodisks

Copper sulfide materials have diverse applications from cancer therapy to environmental remediation due to their narrow bandgap and easily tuned plasmon. The synthesis of these materials often involves toxic reagents and harsh conditions where biomimetic methods may provide opportunities to produce these structures under sustainable conditions. To explore this capability, simple amino acids were exploited as biological ligands for the ambient synthesis of CuS materials. Using an aqueous-based approach, CuS nanodisks were prepared using acid-containing amino acid molecules that stabilize the materials against bulk aggregation. These structures were fully characterized by UV-vis analysis, transmission electron microscopy, dynamic light scattering, atomic force microscopy, selected area electron diffraction, and X-ray diffraction, which confirmed the formation of CuS. The materials possessed a vibrant plasmon band in the near IR region and demonstrated enhanced photocatalytic reactivity for the advanced oxidation of organic dyes in water. These results demonstrate a room temperature synthetic route to optically important materials, which could have important application in catalysis, optics, nanomedicine, etc

Amino Acids for the Sustainable Production of Cu2O Materials: Effects on Morphology and Photocatalytic Reactivity

Photocatalytic technologies represent intriguing approaches for long-term environmental remediation strategies; however, approaches to sustainably generate the catalytic materials remain limited. Many methods require the use of toxic surfactants and potentially harsh conditions. As an alternative, bioinspired approaches present pathways toward the production of functional structures under ambient conditions. In this contribution, the effects of amino acids in the low-temperature production of Cu2O-based materials is examined, providing first principle information for the eventual de novo design of peptides that can control the structure/function relationship of these inorganic materials. These studies demonstrate that only a fraction of the 20 canonical amino acids (Arg, Cys, Glu, His, Lys, and Trp) possess specific control over the morphology and size of Cu2O materials during the synthetic process. This level of control is shown to directly affect the photocatalytic activity of the materials for the degradation of model organic pollutants. Taken together, these results provide intriguing new directions for the rational design of sustainable synthetic approaches for the production of catalytically important semiconductor metal oxide materials applied to long-term environmental remediation capabilities

Space-charge effects in Penning ion traps

The influence of space-charge on ion cyclotron resonances and magnetron eigen frequency in a gas-filled Penning ion trap has been investigated. Off-line measurements with 39K using the cooling trap of the WITCH retardation spectrometer-based setup at ISOLDE/CERN were performed. Experimental ion cyclotron resonances were compared with ab initio Coulomb simulations and found to be in agreement. As an important systematic effect of the WITCH experiment,the magnetron eigen frequency of the ion cloud was studied under increasing space-charge conditions. Finally, the helium buffer gas pressure in the Penning trap was determined by comparing experimental cooling rates with simulations.publisher: Elsevier articletitle: Space-charge effects in Penning ion traps journaltitle: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment articlelink: http://dx.doi.org/10.1016/j.nima.2015.02.057 content_type: article copyright: Copyright © 2015 CERN for the benefit of the Authors. Published by Elsevier B.V.status: publishe

Search for a scalar component in the weak interaction

The WITCH project (Weak Interaction Trap for CHarged particles) at the isotope separator ISOLDE at CERN is trying to probe the structure of the weak interaction in specific low energy beta–decays in order to look for possible scalar or tensor components or at least significantly improve the current experimental limits. This worldwide unique experimental setup consisting of a combination of two Penning ion traps and a retardation spectrometer allows to catch, trap and cool the radioactive nuclei provided by the ISOLDE separator, form a cooled and scattering-free radioactive source of beta–decaying nuclei and let these nuclei decay at rest. The precise measurement of the shape of the energy spectrum of the recoiling nuclei, the shape of which is very sensitive to the character of the weak interaction, enables searching for a possible admixture of a scalar/tensor component in the dominant vector/axial vector mode.status: publishe

Search for a scalar component in the weak interaction

Weak interactions are described by the Standard Model which uses the basic assumption of a pure “V(ector)-A(xial vector)” character for the interaction. However, after more than half a century of model development and experimental testing of its fundamental ingredients, experimental limits for possible admixtures of scalar and/or tensor interactions are still as high as 7%. The WITCH project (Weak Interaction Trap for CHarged particles) at the isotope separator ISOLDE at CERN is trying to probe the structure of the weak interaction in specific low energy $\beta$–decays in order to look for possible scalar or tensor components or at least significantly improve the current experimental limits. This worldwide unique experimental setup consisting of a combination of two Penning ion traps and a retardation spectrometer allows to catch, trap and cool the radioactive nuclei provided by the ISOLDE separator, form a cooled and scattering-free radioactive source of $\beta$–decaying nuclei and let these nuclei decay at rest. The precise measurement of the shape of the energy spectrum of the recoiling nuclei, the shape of which is very sensitive to the character of the weak interaction, enables searching for a possible admixture of a scalar/tensor component in the dominant vector/axial vector mode. First online measurements with the isotope $^{35}$Ar were performed in 2011 and 2012. The current status of the experiment, the data analysis and results as well as extensive simulations will be presented and discussed