Search results for "carbon (C)"

Metal–Organic Frameworks (MOFs) Containing Adsorbents for Carbon Capture

2022

This research was funded by the European Regional Development Fund project “Innovation of the waste‐to‐energy concept for the low carbon economy: development of novel carbon capture technology for thermochemical processing of municipal solid waste (carbon capture and storage from waste—CCSW)”, grant number 1.1.1.1/19/A/013.

Theoretical absorption spectrum of the Ar–CO van der Waals complex

2003

The three-dimensional intermolecular electric dipole moment surface of Ar–CO is calculated at the coupled cluster singles and doubles level of theory with the aug-cc-pVTZ basis set extended with a 3s3p2d1f1g set of midbond functions. Using the rovibrational energies and wave functions of our recent study [J. Chem. Phys. 117, 6562 (2002)], temperature-dependent spectral intensities are evaluated and compared to available experimental data. Based on the theoretical spectrum, alternative assignments of the experimentally observed lines in the fundamental band of CO around 2160 and 2166 cm−1 are suggested. Thomas.Bondo@uv.es

SOLUTRENSES DEL SUR DE IBERIA EN TRANSICIÓN

2013

La cuestión de las relaciones tecnoeconómicas entre el Solutrense y los complejos que lo enmarcan (Gravetiense y Badeguliense) permanence abierta y condicionada por los procesos erosivos que coinciden con estos momentos en la mayoría de yacimientos de la región mediterránea ibérica. El análisis de las industrias líticas de Parpalló y Nerja, así como el conjunto de las dataciones radiocarbónicas permite una aproximación a estas relaciones y una evaluación crítica de su marco cronológico.The relationship between the Solutrean and the Gravettian and Badegoulian is still an open issue, and the analysis of this relationship in most sites appears to be conditioned by the effects of erosive proces…

Global and time-resolved monitoring of crop photosynthesis with chlorophyll fluorescence

2014

Guanter, Luis et al.

The carbon count of 2000 years of rice cultivation.

2013

More than 50% of the world's population feeds on rice. Soils used for rice production are mostly managed under submerged conditions (paddy soils). This management, which favors carbon sequestration, potentially decouples surface from subsurface carbon cycling. The objective of this study was to elucidate the long-term rates of carbon accrual in surface and subsurface soil horizons relative to those of soils under nonpaddy management. We assessed changes in total soil organic as well as of inorganic carbon stocks along a 2000-year chronosequence of soils under paddy and adjacent nonpaddy management in the Yangtze delta, China. The initial organic carbon accumulation phase lasts much longer a…

Top consumer abundance influences lake methane efflux

2015

Lakes are important habitats for biogeochemical cycling of carbon. The organization and structure of aquatic communities influences the biogeochemical interactions between lakes and the atmosphere. Understanding how trophic structure regulates ecosystem functions and influences greenhouse gas efflux from lakes is critical to understanding global carbon cycling and climate change. With a whole-lake experiment in which a previously fishless lake was divided into two treatment basins where fish abundance was manipulated, we show how a trophic cascade from fish to microbes affects methane efflux to the atmosphere. Here, fish exert high grazing pressure and remove nearly all zooplankton. This re…

Microbial microstratification, inorganic carbon photoassimilation and dark carbon fixation at the chemocline of the meromictic Lake Cadagno (Switzerl…

2001

The microstratification of the microbial community at the chemocline of Lake Cadagno and the associated inorganic carbon fixation activity was studied by fine layer sampling. A deep chlorophyll maximum caused by diatoms overlying Cryptomonas was found at the upper edge of the chemocline. A high population density of phototrophic sulphur bacteria, mainly Amoebobacter cf. purpureus, occurred closely below the oxic-anoxic boundary. Despite the small fraction of total lake volume represented by the chemocline, half of the total carbon photoassimilation of the lake occurred within the chemocline with approximately equal contributions by oxygenic and anoxygenic phototrophs. Rates of dark carbon f…

Quantifying the spatial extent and intensity of recent extreme drought events in the Amazon rainforest and their impacts on the carbon cycle

2020

Over the last decades, the Amazon rainforest was hit by multiple severe drought events. Here we assess the severity and spatial extent of the extreme drought years 2005, 2010, and 2015/2016 in the Amazon region and their impacts on the carbon cycle. As an indicator of drought stress in the Amazon rainforest, we use the widely applied maximum cumulative water deficit (ΔMCWD). Evaluating an ensemble of ten state-of-the-art precipitation datasets for the Amazon region, we find that the spatial extent of the drought in 2005 ranges from 2.8 to 4.2 (mean = 3.2) million km2 (46–71 % of the Amazon basin, mean = 53 %) where ΔMCWD indicates at le…

Environmental and Human Drivers of Carbon Sequestration and Greenhouse Gas Emissions in the Ebro Delta, Spain

2021

Unified understanding of intrinsic and extrinsic controls of dissolved organic carbon reactivity in aquatic ecosystems

2022

Despite our growing understanding of the global carbon cycle, scientific consensus on the drivers and mechanisms that control dissolved organic carbon (DOC) turnover in aquatic systems is lacking, hampered by the mismatch between research that approaches DOC reactivity from either intrinsic (inherent chemical properties) or extrinsic (environmental context) perspectives. Here we propose a conceptual view of DOC reactivity in which the combination of intrinsic and extrinsic factors controls turnover rates and determines which reactions will occur. We review three major types of reactions (biological, photochemical, and flocculation) from an intrinsic chemical perspective and further define t…