Search results for "parti"
showing 10 items of 19512 documents
Implementation of a comprehensive ice crystal formation parameterization for cirrus and mixed-phase clouds in the EMAC model (based on MESSy 2.53)
2018
A comprehensive ice nucleation parameterization has been implemented in the global chemistry-climate model EMAC to improve the representation of ice crystal number concentrations (ICNCs). The parameterization of Barahona and Nenes (2009, hereafter BN09) allows for the treatment of ice nucleation taking into account the competition for water vapour between homogeneous and heterogeneous nucleation in cirrus clouds. Furthermore, the influence of chemically heterogeneous, polydisperse aerosols is considered by applying one of the multiple ice nucleating particle parameterizations which are included in BN09 to compute the heterogeneously formed ice crystals. BN09 has been modified in order to co…
The chronic effects of fullereneC 60 -associated sediments in the midge Chironomus riparius – Responses in the first and the second generation
2017
Abstract The life cycle parameters of the benthic invertebrate Chironomus riparius make it a relevant organism for use in multi-generation chronic ecotoxicology tests. Since studies on chronic exposures with fullerene carbon nanoparticles have revealed adverse effects at lower concentration ranges, it is crucial to gain understanding of the consequences in following generations. The aims of this study were to investigate whether sediment-associated fullereneC 60 impacts on C. riparius emergence and breeding, thus affecting the growth of the second generation. Larvae were exposed to fullerene-spiked sediment at concentrations of 0.5, 10 and 40 mg/kg sediment dw. Total emergence and breeding …
Characterization of a Newly Developed Aircraft-Based Laser Ablation Aerosol Mass Spectrometer (ALABAMA) and First Field Deployment in Urban Pollution…
2011
We present here the development and first field deployment of a novel Aircraft-based Laser ABlation Aerosol MAss spectrometer (ALABAMA), which is capable of measuring the chemical composition and size of individual ambient aerosol particles in the size range between 150 and 900 nm. The instrument uses a continuous wave 532 nm laser to size and detect the particles, a pulsed 266 nm laser to ablate and ionize the particles, and a bipolar, Z-shaped time-of-flight mass spectrometer to detect positive and negative ions. The ALABAMA fits into a 19"-aircraft rack of 150 cm height and has a total weight of 140 kg, thus currently being one of the smallest and lightest-weight instruments of its type.…
Social vulnerability to climate policies: Building a matrix to assess policy impacts on well-being
2021
In this article, we address the social vulnerability of people to climate mitigation policies and contribute to assessing the social impacts of climate policies by introducing a matrix tool for conducting vulnerability assessments and participatory climate policy planning. The matrix serves as a methodological tool for identifying social groups in their social spaces. First, we lay the foundation for the matrix by linking social vulnerability to equality and justice, demonstrating the importance of addressing social vulnerability in climate policy design and research. Next, we introduce the ways in which social vulnerability has been addressed in the integration of social and climate policy…
Influence of dissolved organic matter on rare earth elements and yttrium distributions in coastal waters
2010
International audience; Data collected during this study indicate that dissolved Y and REE (rare earth element) behaviour can be monitored through shale-normalised ratios. Relationships occurring between these ratios suggest that leaching from lithogenic materials is the main source of REE in the studied area. This process involves riverine detrital matter in the inner area of the Gulf of Palermo. Features of shale-normalised patterns and the relationship recognised between dissolved Fe and Y/Ho suggest that REE are released from Fe-rich coatings of atmospheric dust. Observed similarities between dissolved Fe and chlorophyll- content suggest that leaching of Fe-rich atmospheric particulates…
ESR/U-series chronology of early Neanderthal occupations at Cova Negra (Valencia, Spain)
2019
Abstract The spatiotemporal repartition of Neanderthal populations throughout the late Middle and early Upper Pleistocene is of great interest for our understanding of human evolution. Establishing a reliable chronology for human-bearing layers from prehistoric sites is thus essential for the study of Neanderthal population dynamics prior to modern human arrival in Europe. Cova Negra (Valencia, Spain) is one of the richest sites documenting Neanderthal fossil bones in the Iberian Peninsula (Arsuaga et al., 1989, 2007; Villaverde et al., 2014). The stratigraphic sequence includes 15 Middle Palaeolithic layers. Among them, four were dated by the ESR/U-series dating method on enamel from six h…
TRACKING DINOSAURS IN COARSE-GRAINED SEDIMENTS FROM THE UPPER TRIASSIC OF ARDÈCHE (SOUTHEASTERN FRANCE)
2020
ABSTRACT Coarse-grained sediments deposited in high-energy environments are usually considered unfavorable to the preservation of fossil tracks. Here we report dinosaur footprints showing good physical preservation, despite being found in coarse-grained sandstones of alluvial origin from the Upper Triassic of Ardèche, southeastern France. The ichnoassemblage, dominated by Grallator isp., raises questions about the processes leading to the formation and preservation of tracks in coarse-grained sediments. The track-bearing surface is a medium- to coarse-grained quartz arenite that is microconglomeratic locally. The tracking surface grain size ranges from 0.2 to 2 mm and numerous pebbles are p…
Burned bones forensic investigations employing near infrared spectroscopy
2017
The use of near infrared (NIR) spectroscopy was evaluated, by using chemometric tools, for the study of the environmental impact on burned bones. Spectra of internal and external parts of burned bones, together with sediment samples, were treated by Principal Component Analysis and cluster classification as exploratory techniques to select burned bone samples, less affected by environmental processes, to properly carry out forensic studies. Partial Least Square Discriminant Analysis was used to build a model to classify bone samples based on their burning conditions, providing an efficient and accurate method to discern calcined and carbonized bone. Additionally, Partial Least Square regres…
Effect of Intensity and Mode of Artificial Upwelling on Particle Flux and Carbon Export
2021
Reduction of anthropogenic CO2 emissions alone will not sufficiently restrict global warming and enable the 1.5°C goal of the Paris agreement to be met. To effectively counteract climate change, measures to actively remove carbon dioxide from the atmosphere are required. Artificial upwelling has been proposed as one such carbon dioxide removal technique. By fueling primary productivity in the surface ocean with nutrient-rich deep water, it could potentially enhance downward fluxes of particulate organic carbon (POC) and carbon sequestration. In this study we investigated the effect of different intensities of artificial upwelling combined with two upwelling modes (recurring additions vs. on…
Drivers of shell growth of the bivalve, Callista chione (L. 1758) - Combined it environmental and biological factors
2018
WOS:000426027100014; Seasonal shell growth patterns were analyzed using the stable oxygen and carbon isotope values of live-collected specimens of the bivalve Callista chione from two sites in the Adriatic Sea (Pag and Cetina, Croatia). Micromilling was performed on the shell surface of three shells per site and shell oxygen isotopes of the powder samples were measured. The timing and rate of seasonal shell growth was determined by aligning the delta O-18(shell)-derived temperatures so that the best fit was achieved with the instrumental temperature curve. According to the data, shells grew only at very low rates or not at all during the winter months, i.e., between January and March. Shell…