30 research outputs found
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Erratum: "The Longest Delay: A 14.5 yr Campaign to Determine the Third Time Delay in the Lensing Cluster SDSS J1004+4112" (2022, ApJ, 937, 34)
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The Longest Delay: A 14.5 yr Campaign to Determine the Third Time Delay in the Lensing Cluster SDSS J1004+4112
We present new light curves for the four bright images of the five image cluster-lensed quasar gravitational lens system SDSS J1004+4112. The light curves span 14.5 yr and allow the measurement of the time delay between the trailing bright quasar image D and the leading image C. When we fit all four light curves simultaneously and combine the models using the Bayesian information criterion, we find a time delay of Ît DC = 2458.47 ± 1.02 days (6.73 yr), the longest ever measured for a gravitational lens. For the other two independent time delays we obtain Ît BC = 782.20 ± 0.43 days (2.14 yr) and Ît AC = 825.23 ± 0.46 days (2.26 yr), in agreement with previous results. The information criterion is needed to weight the results for light curve models with different polynomial orders for the intrinsic variability and the effects of differential microlensing. The results using the Akaike information criterion are slightly different, but, in practice, the absolute delay errors are all dominated by the âŒ4% cosmic variance in the delays rather than the statistical or systematic measurement uncertainties. Despite the lens being a cluster, the quasar images show slow differential variability due to microlensing at the level of a few tenths of a magnitude
Assessment of the F@rma-ciĂłn learning resources
ResĂșmenes IV Congreso VetDoc de Docencia Veterinaria, LeĂłn 2017 (6-7 de Julio)[ES] En el presente trabajo presentamos parte de los objetivos desarrollados en este proyecto, concretamente los relacionados con la exploraciĂłn del metaconocimiento de los estudiantes en cuanto a la adquisiciĂłn de competencias, tanto transversales como especĂficas de farmacologĂa mediante la realizaciĂłn de las actividades y utilizaciĂłn de los recursos generados en el repositorio de F@RMA-CIĂN
A mathematical analysis of the evolution of perturbations in a modified Chaplygin gas model
One approach in modern cosmology consists in supposing that dark matter and
dark energy are different manifestations of a single `quartessential' fluid.
Following such idea, this work presents a study of the evolution of
perturbations of density in a flat cosmological model with a modified Chaplygin
gas acting as a single component. Our goal is to obtain properties of the model
which can be used to distinguish it from another cosmological models which have
the same solutions for the general evolution of the scale factor of the
universe, without the construction of the power spectrum. Our analytical
results, which alone can be used to uniquely characterize the specific model
studied in our work, show that the evolution of the density contrast can be
seen, at least in one particular case, as composed by a spheroidal wave
function. We also present a numerical analysis which clearly indicates as one
interesting feature of the model the appearence of peaks in the evolution of
the density constrast.Comment: 21 pages, accepted for publication in General Relativity and
Gravitatio
Mitigation of phytotoxic effect of compost by application of optimized aqueous extraction protocols
The abuse of chemical fertilizers in recent decades has led the promotion of less harmful alternatives, such as compost
or aqueous extracts obtained from it. Therefore, it is essential to develop liquid biofertilizers, which in addition of
being stable and useful for fertigation and foliar application in intensive agriculture had a remarkable phytostimulant
extracts. For this purpose, a collection of aqueous extracts was obtained by applying four different Compost Extraction
Protocols (CEP1, CEP2, CEP3, CEP4) in terms of incubation time, temperature and agitation of compost samples from
agri-food waste, olive mill waste, sewage sludge and vegetable waste. Subsequently, a physicochemical characterization
of the obtained set was performed in which pH, electrical conductivity and Total Organic Carbon (TOC) were measured.
In addition, a biological characterization was also carried out by calculating the Germination Index (GI) and
determining the Biological Oxygen Demand (BOD5). Furthermore, functional diversity was studied using the Biolog
EcoPlates technique. The results obtained confirmed the great heterogeneity of the selected raw materials. However,
it was observed that the less aggressive treatments in terms of temperature and incubation time, such as CEP1 (48 h,
room temperature (RT)) or CEP4 (14 days, RT), provided aqueous compost extracts with better phytostimulant characteristics
than the starting composts. It was even possible to find a compost extraction protocol that maximize the beneficial
effects of compost. This was the case of CEP1, which improved the GI and reduced the phytotoxicity in most of
the raw materials analyzed. Therefore, the use of this type of liquid organic amendment could mitigate the phytotoxic
effect of several composts being a good alternative to the use of chemical fertilizers
TRY plant trait database â enhanced coverage and open access
Plant traitsâthe morphological, anatomical, physiological, biochemical and phenological characteristics of plantsâdetermine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of traitâbased plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traitsâalmost complete coverage for âplant growth formâ. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and traitâenvironmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives
Effects of annealing treatment prior to cold rolling on delayed fracture properties in ferrite-austenite duplex lightweight steels
Tensile properties of recently developed automotive high-strength steels containing about 10 wt pct of Mn and Al are superior to other conventional steels, but the active commercialization has been postponed because they are often subjected to cracking during formation or to the delayed fracture after formation. Here, the delayed fracture behavior of a ferrite-austenite duplex lightweight steel whose microstructure was modified by a batch annealing treatment at 1023 K (750 A degrees C) prior to cold rolling was examined by HCl immersion tests of cup specimens, and was compared with that of an unmodified steel. After the batch annealing, band structures were almost decomposed as strong textures of {100}aOE (c) 011 > alpha-fibers and {111}aOE (c) 112 > gamma-fibers were considerably dissolved, while ferrite grains were refined. The steel cup specimen having this modified microstructure was not cracked when immersed in an HCl solution for 18 days, whereas the specimen having unmodified microstructure underwent the delayed fracture within 1 day. This time delayed fracture was more critically affected by difference in deformation characteristics such as martensitic transformation and deformation inhomogeneity induced from concentration of residual stress or plastic strain, rather than the difference in initial microstructures. The present work gives a promise for automotive applications requiring excellent mechanical and delayed fracture properties as well as reduced specific weight.ope
POSSIBLE USE OF BANANA BUNCH RACHIS JUICE TO CONTROL THE FUNGUS SCLEROTIUM ROLFSII SACC.
The present study reports the possible use of the Banana bunch rachis(BBR, a residue generally lost or neglected in Guadeloupe and Martinique) as an organic amendment of the soil to control the stem blight fungus Sclerotium rolfsii. The soil amended with the residue at the dose of 4%(w:w) was suppressive to the fungus. In fact, the active part of the BBR was in the juice which was still effective after heating (boiling or autoclaving). The BBR juice decreased the soil infectious potential due to S. rolfsii and affected the growth of the fungus in laboratory experiments. In the field, it also reduced the population of viable S. rolfsii sclerotia. Non-toxic and toxic fractions ( operating in different soil types) were extracted from the juice