| 1. |
- Abolfathi, Bela, et al.
(författare)
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The LSST DESC DC2 Simulated Sky Survey
- 2021
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Ingår i: Astrophysical Journal Supplement Series. - : American Astronomical Society. - 0067-0049 .- 1538-4365. ; 253:31
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Tidskriftsartikel (refereegranskat)abstract
- We describe the simulated sky survey underlying the second data challenge (DC2) carried out in preparation for analysis of the Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST) by the LSST Dark Energy Science Collaboration (LSST DESC). Significant connections across multiple science domains will be a hallmark of LSST; the DC2 program represents a unique modeling effort that stresses this interconnectivity in a way that has not been attempted before. This effort encompasses a full end-to-end approach: starting from a large N-body simulation, through setting up LSST-like observations including realistic cadences, through image simulations, and finally processing with Rubin's LSST Science Pipelines. This last step ensures that we generate data products resembling those to be delivered by the Rubin Observatory as closely as is currently possible. The simulated DC2 sky survey covers six optical bands in a wide-fast-deep area of approximately 300 deg2, as well as a deep drilling field of approximately 1 deg2. We simulate 5 yr of the planned 10 yr survey. The DC2 sky survey has multiple purposes. First, the LSST DESC working groups can use the data set to develop a range of DESC analysis pipelines to prepare for the advent of actual data. Second, it serves as a realistic test bed for the image processing software under development for LSST by the Rubin Observatory. In particular, simulated data provide a controlled way to investigate certain image-level systematic effects. Finally, the DC2 sky survey enables the exploration of new scientific ideas in both static and time domain cosmology.
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| 2. |
- Brackin, Richard, et al.
(författare)
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Nitrogen fluxes at the root-soil interface show a mismatch of nitrogen fertilizer supply and sugarcane root uptake capacity
- 2015
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- Globally only approximate to 50% of applied nitrogen (N) fertilizer is captured by crops, and the remainder can cause pollution via runoff and gaseous emissions. Synchronizing soil N supply and crop demand will address this problem, however current soil analysis methods provide little insight into delivery and acquisition of N forms by roots. We used microdialysis, a novel technique for in situ quantification of soil nutrient fluxes, to measure N fluxes in sugarcane cropping soils receiving different fertilizer regimes, and compare these with N uptake capacities of sugarcane roots. We show that in fertilized sugarcane soils, fluxes of inorganic N exceed the uptake capacities of sugarcane roots by several orders of magnitude. Contrary, fluxes of organic N closely matched roots' uptake capacity. These results indicate root uptake capacity constrains plant acquisition of inorganic N. This mismatch between soil N supply and root N uptake capacity is a likely key driver for low N efficiency in the studied crop system. Our results also suggest that (i) the relative contribution of inorganic N for plant nutrition may be overestimated when relying on soil extracts as indicators for root-available N, and (ii) organic N may contribute more to crop N supply than is currently assumed.
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| 3. |
- Carracedo, Juan Carlos, et al.
(författare)
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Reply to Comment on “Recent unrest at Canary Islands' Teide Volcano?”
- 2007
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Ingår i: EOS. - 0096-3941 .- 2324-9250. ; 88:46, s. 488-
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Small-magnitude seismic episodes unrelated to a volcanic eruption have been a relatively frequent feature in all the Canaries without causing any significant public alarm. Conversely, great alarm was raised in May 2004 in Tenerife, when apparently numerous low-magnitude seismic signals were recorded, although only a few of them were actually felt in nearby villages.Public alarm was raised by (1) the publication on a Web site of imperceptible seismic signals as low as 0.6 on the Richter scale, most of which were not even adequately localized and yet were reproduced almost daily in the local and national press without further comment or explanation; (2) a Spanish national scientific committee being replaced by a local committee that was scientifically advised by a private company; and (3) publicity given by the media to the prediction made by members of the local committee of a potentially large scale explosive eruption in October 2004 (dubbed “the October volcano” by residents). Interestingly, obvious fumarole activity was absent in autumn 2004 during an inspection of Teide summit by three of us.
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| 4. |
- Spartacus, Gabriel, et al.
(författare)
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Characterization of the nature and morphology of coarse precipitation in various oxide dispersion strengthened steels
- 2021
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Ingår i: Materialia. - : Elsevier BV. - 2589-1529. ; 17
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Tidskriftsartikel (refereegranskat)abstract
- Oxide Dispersion Strengthened (ODS) steels are candidate materials for both fission and fusion nuclear reactors. In this study, the microstructure of ferritic (Fe-14Cr-1W) and ferritic / martensitic (Fe-9Cr-1W) ODS steels has been characterized after two different processing routes: Hot Extrusion (HE) and Hot Isostatic Pressing (HIP). Transmission Kikuchi Diffraction (TKD) revealed the presence of Ti-rich precipitates on every specimen. They are identified by X-Ray Diffraction (XRD) as Ti(C,N) and Ti-O (Ti2O3 or TiO2). Intergranular M7C3 and M23C6 have been observed on most Fe-14Cr ODS steels except one, where no Cr-carbides have been found. In Fe-9Cr ODS, intergranular Cr-rich M23C6 carbides have been found. The lack of M7C3 on Fe-9Cr ODS is possibly linked to the matrix phase transformation, not occurring in the Fe-14Cr ODS. Cr-carbides display highly elongated shapes for the Fe-14Cr HE specimens that could be detrimental to the mechanical behavior of the material.
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