3,659 research outputs found
Imaging the Kirkendall effect in pyrite (FeS2) thin films: cross-sectional microstructure and chemical features
This investigation provides novel data on the structure and chemical composition of pyrite thin films and new hints concerning their formation mechanism. From TEM-HAADF data, it has been found that the films are composed of two different layers: one is very compact and the other one is quite porous with many voids separating a few groups of grains. This porous layer is always in direct contact with the substrate, and its thickness is quite similar to that of the original Fe film. The average size of pyrite grains is equal in both layers, what suggests that the same process is responsible for their formation. Concentration profiles of sulfur, iron and some impurities (mainly sodium and oxygen from the glass substrate) through both layers are given in this work, and thus chemical inhomogeneities of the films are proved by the obtained stoichiometric ratios (S/Fe). Moreover, Na from sodalime glass substrates mainly accumulates at the pyrite grain boundaries and barely dopes them. The obtained results support the hypothesis that the iron sulfuration process essentially induces the diffusion of iron atoms, what leads to the porous layer formation as a manifestation of the Kirkendall Effect. Therefore, it seems that the same mechanisms that operate in the synthesis of surface hollow structures at the nanoscale are also active in the formation of pyrite thin films ranging from several tens to hundreds of nanometersMembers of MIRE Group acknowledge the financial support of the Spanish MICINN under project RTI2018-099794-B-I00. E. Flores acknowledges the intramural CSIC project 2D-MeSes funding and the service from the MiNa Laboratory at IMN, and funding from CM (project SpaceTec, S2013/ICE2822), MINECO (project CSIC13-4E1794) and EU (FEDER,FSE). Financial support through the project UMA18-FEDERJA-041 is gratefully acknowledge
SSDSS IV MaNGA - Properties of AGN host galaxies
We present here the characterization of the main properties of a sample of 98
AGN host galaxies, both type-II and type-I, in comparison with those of about
2700 non-active galaxies observed by the MaNGA survey. We found that AGN hosts
are morphologically early-type or early-spirals. For a given morphology AGN
hosts are, in average, more massive, more compact, more central peaked and
rather pressurethan rotational-supported systems. We confirm previous results
indicating that AGN hosts are located in the intermediate/transition region
between star-forming and non-star-forming galaxies (i.e., the so-called green
valley), both in the ColorMagnitude and the star formation main sequence
diagrams. Taking into account their relative distribution in terms of the
stellar metallicity and oxygen gas abundance and a rough estimation of their
molecular gas content, we consider that these galaxies are in the process of
halting/quenching the star formation, in an actual transition between both
groups. The analysis of the radial distributions of the starformation rate,
specific star-formation rate, and molecular gas density shows that the
quenching happens from inside-out involving both a decrease of the efficiency
of the star formation and a deficit of molecular gas. All the intermediate
data-products used to derive the results of our analysis are distributed in a
database including the spatial distribution and average properties of the
stellar populations and ionized gas, published as a Sloan Digital Sky Survey
Value Added Catalog being part of the 14th Data Release:
http://www.sdss.org/dr14/manga/manga-data/manga-pipe3d-value-added-catalog/Comment: 48 pages, 14 figures, in press in RMxA
Metallofluorescent Nanoparticles for Multimodal Applications
Herein, we describe
the synthesis and application of cross-linked
polystyrene-based dual-function nano- and microparticles containing
both fluorescent tags and metals. Despite containing a single dye,
these particles exhibit a characteristic dual-band fluorescence emission.
Moreover, these particles can be combined with different metal ions
to obtain hybrid metallofluorescent particles. We demonstrate that
these particles are easily nanofected into living cells, allowing
them to be used for effective fingerprinting in multimodal fluorescence-based
and mass spectrometry-based flow cytometry experiments. Likewise,
the in situ reductions of the metal ions enable other potential uses
of the particles as heterogeneous catalysts
Manganese oxides as biominerals in a granitic subterranean environment
Black coatings were detected on granite surfaces in groundwater catch work tunnels from Porto city (NW Portugal). XRD, FTIR, Micro-Raman, ICP-MS, TEM-EDS, SEM-EDS and SEM-FIB were the analytical procedures carried out to investigate the origin of the black coatings. In this subterranean environment, the enrichment in metals and other trace elements, such as Mn and Fe, and clay minerals characterize the black microbial mats, mainly composed of Mn/Fe-oxidising bacteria.Fundação para a Ciência e a Tecnologia (FCT
Nutrition screening tools for risk of malnutrition among hospitalized patients
Background:
Malnutrition is a clinical problem with a high prevalence in hospitalized adult patients. Many nutritional screening tools have been developed but there is no consensus on which 1 is more useful. The purpose of this review protocol is to provide an overview of which nutritional screening tool is most valid to identify malnutritional risk in hospitalized adult patients and to analyze the sensitivity and specificity of the different tools.
Methods:
The protocol of this systematic review and meta-analysis was registered on the INPLASY website (https://inplasy.com/inplasy-2020-9-0028/) and INPLASY registration number is INPLASY202090028. We will perform a systematic literature search of main databases: PubMed, EMBASE, CINAHL and Web of Science and the Cochrane database. Also, grey literature will be search. Peer-reviewed studies published in English, Portuguese or Spanish language will be selected. Screening of titles, abstract and full text will be assessed for eligibility by 2 independent blinded reviewers and any discrepancies will be resolved via consensus. After screening the studies, a meta-analysis will be conducted, if it is possible.
Results:
Results from this systematic review will help health professionals to identify malnutrition in hospitalized patients and to make decisions to prevent or treat it as well as provide new clues to researchers.
Conclusion:
Our systematic review will provide aknowledge about the most valid malnutrition risk screening tool in hospitalized adult patients
Intelligent Monitoring System for Bird Behavior Study
Until now, the best way to obtain relevant information about the
behaviour of animals is capturing them. However, the procedure to capture
individuals cause them stress and introduces an effect on the measurement that
can affect the behaviour of the animals. To solve this problems this paper
describes a novel intelligent motoring system for birds breeding in nest boxes.
This system is based in a network of smart-nest boxes that allows access to the
acquired data all over the world through internet. A prototype of the proposed
system has been implemented for the evaluation of a lesser kestrel breeding
colony in Southern Spain. This prototype has offered in a short time more
valuable information that several years of manual captures. This prototype has
demonstrated that the proposed system allows short and log time animal
behaviour evaluation without interferences or causing stress.Junta de Andalucía P06-RNM-01712Junta de Andalucía P06-RNM-04588Junta de Andalucía P07-TIC-02476Junta de Andalucía TIC-570
Self-organization in the olfactory system: one shot odor recognition in insects
We show in a model of spiking neurons that synaptic plasticity in the mushroom bodies in combination with the general fan-in, fan-out properties of the early processing layers of the olfactory system might be sufficient to account for its efficient recognition of odors. For a large variety of initial conditions the model system consistently finds a working solution without any fine-tuning, and is, therefore, inherently robust. We demonstrate that gain control through the known feedforward inhibition of lateral horn interneurons increases the capacity of the system but is not essential for its general function. We also predict an upper limit for the number of odor classes Drosophila can discriminate based on the number and connectivity of its olfactory neurons
Neutron-rich fragments produced by in-flight fission of U-238
The production cross sections of neutron-rich fission residues in reactions induced by U-238 projectiles at 950A MeV impinging on Pb and Be targets are investigated at the Fragment Separator at GSI. These two targets allow us to investigate fission processes induced by two reaction mechanisms, Coulomb and nuclear excitations, and to study the role of these mechanisms in the neutron excess of the final fragments.Peer reviewe
An Overview of the 2014 ALMA Long Baseline Campaign
A major goal of the Atacama Large Millimeter/submillimeter Array (ALMA) is to
make accurate images with resolutions of tens of milliarcseconds, which at
submillimeter (submm) wavelengths requires baselines up to ~15 km. To develop
and test this capability, a Long Baseline Campaign (LBC) was carried out from
September to late November 2014, culminating in end-to-end observations,
calibrations, and imaging of selected Science Verification (SV) targets. This
paper presents an overview of the campaign and its main results, including an
investigation of the short-term coherence properties and systematic phase
errors over the long baselines at the ALMA site, a summary of the SV targets
and observations, and recommendations for science observing strategies at long
baselines. Deep ALMA images of the quasar 3C138 at 97 and 241 GHz are also
compared to VLA 43 GHz results, demonstrating an agreement at a level of a few
percent. As a result of the extensive program of LBC testing, the highly
successful SV imaging at long baselines achieved angular resolutions as fine as
19 mas at ~350 GHz. Observing with ALMA on baselines of up to 15 km is now
possible, and opens up new parameter space for submm astronomy.Comment: 11 pages, 7 figures, 2 tables; accepted for publication in the
Astrophysical Journal Letters; this version with small changes to
affiliation
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