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The important task (NBI neutral beam injector for fusion) and the complexity of radiofrequency ion source need large tests (as ELISE and SPIDER) and intermediate scale tests (as NIO1 in this poster) for optimization. Conditioning (with gas) was found necessary in Cs-free operation. Cs-based operation has begun: stability improves at lower oven temperature; in both cases, lateral view cameras show beam quality. Energy recovery plugin almost ready for NIO1 (or at a test station at TRIPS).

In this study we evaluate the skill of a new, merged soil moisture product (ECV_SM) that has been developed in the framework of the European Space Agency's Water Cycle Multi-mission Observation Strategy and Climate Change Initiative projects. The product combines in a synergistic way the soil moisture retrievals from four passive (SMMR, SSM/I, TMI, and AMSR-E) and two active (ERS AMI and ASCAT) coarse resolution microwave sensors into a global data set spanning the period 1979-2010. The evaluation uses ground-based soil moisture observations of 596 sites from 28 historical and active monitoring networks worldwide. Besides providing conventional measures of agreement, we use the triple collocation technique to assess random errors in the data set. The average Spearman correlation coefficient between ECV_SM and all in-situ observations is 0.46 for the absolute values and 0.36 for the soil moisture anomalies, but differences between networks and time periods are very large. Unbiased root-mean-square differences and triple collocation errors show less variation between networks, with average values around 0.05 and 0.04m3m-3, respectively. The ECV_SM quality shows an upward trend over time, but a consistent decrease of all performance metrics is observed for the period 2007-2010. Comparing the skill of the merged product with the skill of the individual input products shows that the merged product has a similar or better performance than the individual input products, except with regard to the ASCAT product, compared to which the performance of ECV_SM is inferior. The cause of the latter is most likely a combination of the mismatch in sampling time between the satellite observations and in-situ measurements, and the resampling and scaling strategy used to integrate the ASCAT product into ECV_SM on the other. The results of this study will be used to further improve the scaling and merging algorithms for future product updates.

Abstract In this article, we study the modification of the optical, chemical and electronic properties of graphene oxide (GO) during thermal reduction in ultra-high-vacuum by combining the results of several electron spectroscopies. We find that the fraction of oxygen moieties on the surface, as deduced from the evolution of C 1s core level in photoemission, is progressively reduced upon increasing the annealing temperature from 150 to 650 °C. The intensity of the CH stretching mode, associated with CH defects on GO surface and measured in the low energy region of electron energy loss spectra (EELS), decreases as a function of the annealing temperature. The removal or the reduction of such hydrogen or oxygen defects induces a restoration of sp2 carbon hybridization. The presence of such hybridization is confirmed by the capability to excite π -plasmon as observed in the EELS spectra. In particular we find a critical annealing temperature (Tann = 300 °C) at which π -plasmon excitation via electron scattering is accessible suggesting the formation of graphene-like domains with size comparable with the plasmon wavelength ( λ p ~ 5 nm). The linear dispersion of π -band close to Fermi level, as measured in UPS, confirms the formation of graphene-like domains.

Abstract Volumetric solar receivers are essential components in high-temperature concentrated solar power plants. Their optical design is crucial for achieving efficient photon-thermal energy conversion; however, their three-dimensional geometry complicates a reliable and accurate optical characterization. This work proposes a new methodology for the 3D optical-performance analysis of the volumetric absorber having an open hierarchical structure. Firstly, the solar absorber is optically characterized using a test bench that mainly comprises a solar simulator and a customized instrument equipped with single-photon avalanche diodes, which holds the absorber and measures light flux on its external surface. Then experimental measurements are compared with a Monte Carlo ray-tracing numerical model. The results are consequently employed to understand light propagation in the absorber. This procedure is successfully applied to characterize a complex three-dimensional self-similar structure manufactured by Selective Laser Melting. The proposed experimental technique is a promising candidate for becoming a robust in operando method to characterize the radiation propagation within the complex porous structures employed for volumetric receivers.

Agroforestry is considered a sustainable form of land management that optimizes the use of natural resources (nutrients, radiation, water). Agroforestry is defined as the deliberate integration of woody vegetation with agricultural activities in the lower story. It provides a higher biomass production per unit of land, while providing more ecosystem services than woody-less agricultural lands, such as the reduction of soil erosion and nitrogen leaching, and increase carbon sequestration and landscape biodiversity. The objective of this paper is to evaluate the past and current European Union Common Agricultural policies aiming at promoting the afforestation or reforestation of lands, as the introduction of trees can be seen as a first step to carry out agroforestry practices in former agricultural or forest lands. Agroforestry was a traditional land use system in Europe before modern times. However, before the sixties land intensification and consolidation destroyed millions of trees all over Europe. On the contrary, some good examples of agroforestry promotion are found in Eastern European countries in order to reduce the effect of extreme events such as winds, flooding at the beginning and mid of the last century. In Western European countries, the introduction of trees in the land has been promoted by agroforestry, afforestation and reforestation at the end of the last century. Afforestation of agricultural lands have been the most successful CAP measure (over 1 million hectares) while agroforestry measures were not extensively adopted which may be explained by the funds associated to afforestation measure which compensated the losses of income 15 or 20 years in afforested lands. Agroforestry was poorly adopted in the CAP 2007-2013, having a better success in the CAP 2014-2020 due to the recognition of woody vegetation and the compensation of 5 years given for maintenance once agroforestry is established. However, policy rules ensuring Pillar I payment when agroforestry measure is adopted such as a management plans ensuring that maximum tree density (100 trees per hectare) is not reached, should be pursued.

Lignocellulosic biomass from agriculture wastes is a potential source of biofuel, but its use is currently limited by the recalcitrance of the plant cell wall to enzymatic digestion. Modification of the wall structural components can be a viable strategy to overcome this bottleneck. We have previously shown that the expression of a fungal polygalacturonase (pga2 from Aspergillus niger) in Arabidopsis and tobacco plants reduces the levels of de-esterified homogalacturonan in the cell wall and significantly increases saccharification efficiency. However, plants expressing pga2 show stunted growth and reduced biomass production, likely as a consequence of an extensive loss of pectin integrity during the whole plant life cycle. We report here that the expression in Arabidopsis of another pectic enzyme, the pectate lyase 1 (PL1) of Pectobacterium carotovorum, under the control of a chemically inducible promoter, results, after induction of the transgene, in a saccharification efficiency similar to that of plants expressing pga2. However, lines with high levels of transgene induction show reduced growth even in the absence of the inducer. To overcome the problem of plant fitness, we have generated Arabidopsis plants that express pga2 under the control of the promoter of SAG12, a gene expressed only during senescence. These plants expressed pga2 only at late stages of development, and their growth was comparable to that of WT plants. Notably, leaves and stems of transgenic plants were more easily digested by cellulase, compared to WT plants, only during senescence. Expression of cell wall-degrading enzymes at the end of the plant life cycle may be therefore a useful strategy to engineer crops unimpaired in biomass yield but improved for bioconversion.

Photon-enhanced thermionic emission (PETE) devices applied to solar energy may be considered as high-temperature solar cells. A cathode structure for PETE was designed for high temperature energy conversion in solar concentrating systems. Surface-hydrogenated diamond is one of the few semiconductors showing negative electron affinity and a work function as low as 1.7 eV if nitrogen doped, that is connected to a significant thermionic emission at moderate temperatures (up to 800 °C, where hydrogen desorbs inducing a positive electron affinity). But diamond is transparent to solar radiation, consequently advanced techniques for preparing an efficient sunlight absorbing diamond are necessary.

Super-hot rock geothermal is an emerging source of renewable and carbon-free energy. This paper is the first attempt to explore fluid and heat flow dynamics in the reservoir-wellbore coupled system, to assess the power generation performance of a super-hot (>450 °C) enhanced geothermal system (EGS). We developed a high-performance code and built a 3-D wellbore-reservoir coupled model based on data from a recently completed deep-drilling project at Larderello, Italy. The general pattern of the super-hot EGS is characterized by a significant temperature plummet (>60 °C), after which the production fluid evolves from steam to a two-phase mixture till the end of the operation period. Reservoir pressure emerges as a key parameter to determine the temperature of the two-phase mixture. By realistically capturing phase transitions driven by coupled thermo-hydraulic processes during operations, our numerical model predicts a lower power generation efficiency compared to previous attempts based on ultra-simplified models. Although finalized at assessing the thermodynamic viability of a specific system, this modeling approach provides general information on fundamental thermo-hydraulic processes in the Earth crust that might be applied for the design of similar EGS projects elsewhere.