891 research outputs found
Enhanced fracture strength in the working layer of rolls manufactured in Ni-hard cast iron alloyed with Mo, Nb and Mg
One of the main in-service failure mechanisms of the work-rolls used in hot strip mill finishing stands is surface spalling. The indefinite chill double-poured rolls usually comprise of a peripheral working layer made of crushed Ni-hard cast iron and a grey cast iron core, mostly pearlitic matrix with spheroidal graphite. To enhance its wear resistance, the working layer can be alloyed with Mo and Nb. The possible cracking and spalling of the surfaces of these work-rolls is strongly influenced by the presence of carbides and the continuity of their network. The flexural and impact toughness tests are reliable testing methods to assess these properties. The aim of this paper is to identify those manufacturing factors that have a significant effect on the flexural strength and toughness of this material, correlating the results with the volume fraction of precipitated carbides. It is worth highlighting, among the analysed factors are the liquidus temperature, the %Si, the use of an inoculant with traces of Lanthanum, and inoculation with different amounts of FeB, SiCa and Mg. Inoculation with SiCa is found to have a positive effect on the toughness of the material, breaking up the continuity of the carbide network, while FeB is found to act as a heterogeneous nucleant for NbC precipitation. However, high FeB contents reduce flexural strength and do not have a significant effect on the hardness of the material. To enhance the fracture toughness of the working layer, a liquidus temperature in the 1270–1275 °C range is recommended, as well as inoculating the ladle with Mg, 3 kg/T FeB and 0.6 kg/T SiCa
Analysis of the 40K contamination in NaI(Tl) crystals from different providers in the frame of the ANAIS project
NaI(Tl) large crystals are applied in the search for galactic dark matter
particles through their elastic scattering off the target nuclei in the
detector by measuring the scintillation signal produced. However, energies
deposited in the form of nuclear recoils are small, which added to the low
efficiency to convert that energy into scintillation, makes that events at or
very near the energy threshold, attributed either to radioactive backgrounds or
to spurious noise (non-bulk NaI(Tl) scintillation events), can compromise the
sensitivity goals of such an experiment. DAMA/LIBRA experiment, using 250 kg
NaI(Tl) target, reported first evidence of the presence of an annual modulation
in the detection rate compatible with that expected for a dark matter signal
just in the region below 6 keVee (electron equivalent energy). In the frame of
the ANAIS (Annual modulation with NaI Scintillators) dark matter search project
a large and long effort has been carried out in order to understand the origin
of events at very low energy in large sodium iodide detectors and develop
convenient filters to reject those non attributable to scintillation in the
bulk NaI(Tl) crystal. 40K is probably the most relevant radioactive contaminant
in the bulk for NaI(Tl) detectors because of its important contribution to the
background at very low energy. ANAIS goal is to achieve levels at or below 20
ppb natural potassium. In this paper we will report on our effort to determine
the 40K contamination in several NaI(Tl) crystals, by measuring in coincidence
between two (or more) of them. Results obtained for the 40K content of crystals
from different providers will be compared and prospects of the ANAIS dark
matter search experiment will be briefly reviewed.Comment: Submitted to International Journal of Modern Physics
Growth of preterm infants at the time of global obesity
Preterm birth, 90% of which occurs between 32 and <37 weeks' gestation,1 2 is a complex heterogeneous syndrome interlinked with the stillbirth and intrauterine growth restriction syndromes. Its phenotypes are associated with different gains in neonatal weight, morbidity and mortality, and perhaps body composition, growth and development. Preterm birth is related to several aetiologies, although nearly 30% of all preterm births are not associated with any maternal/pregnancy conditions or fetal growth restriction
Interleukin 18 maintains a long-standing inflammation in coeliac disease patients
Producción CientíficaDietary gluten induces an early response in the intestine of coeliac disease
patients (CD), within a few hours, and this is driven by high levels of proinflammatory
cytokines, including IFNg and IL-15, as has been thoroughly
shown by gluten stimulation of biopsy explants. Our aim was to identify the
immune mediators involved in the long-standing inflammation in untreated
CD patients at diagnosis. mRNA and protein levels of TNFa, IL-12(p35),
IL-12(p40), IL-15, IL-18 and IL-23(p19) were quantified in biopsies from
active CD patients, CD patients on a gluten-free diet (GFD), healthy controls,
and patients with non-CD inflammation and mild histological changes in the
intestine. Biopsies from CD patients on a GFD were also stimulated in vitro
with gliadin, and protein expression of IL-15 and IL-18 was analysed. Levels of
IL-12 and IL-23 mRNA are nearly absent, and TNFa levels remain unchanged
among different groups. Both the active and inactive forms of IL-18 protein
have been found in all samples from active CD, and protein expression was
only localized within the crypts. Levels of IL-15 mRNA remain unchanged,
and protein expression, localized within the lamina propria, is found in a
small number of samples. In vitro stimulation with gluten induces the expression
of IL-15 and IL-18. In active CD, the early response following gluten
intake characterized by high IFNg levels is driven by IL-18, and probably
IL-15, and this alternates with periods of long-standing inflammation with
moderate IFNg levels, maintained by IL-18 alone
Fall Detection Analysis Using a Real Fall Dataset
International Conference on Soft Computing Models in Industrial and Environmental Applications (13th. 2018. San Sebastián
Surface-Enhanced Raman Scattering Detection of Nucleic Acids Exhibiting Sterically Accessible Guanines Using Ruthenium-Polypyridyl Reagents
This is the peer reviewed version of the following article: Martínez-Calvo, M.; Guerrini,
L.; Rodríguez, J.; Álvarez Puebla, R. A.; Mascareñas, J. L. (2020), Surface-enhanced Raman
Scattering Detection of Nucleic Acids exhibiting Sterically Accessible Guanines using
Ruthenium-polypyridyl Reagents. J. Phys. Chem. Lett., 11: 7218–7223, which has been
published in final form at https://doi.org/10.1021/acs.jpclett.0c02148. This article may be
used for non-commercial purposes in accordance with ACS Terms and Conditions for Use
of Self-Archived VersionsHere, we report the application of surface-enhanced Raman scattering (SERS) spectroscopy as a rapid and practical tool for assessing the formation of coordinative adducts between nucleic acid guanines and ruthenium polypyridyl reagents. The technology provides a practical approach for the wash-free and quick identification of nucleic acid structures exhibiting sterically accessible guanines. This is demonstrated for the detection of a quadruplex-forming sequence present in the promoter region of the c-myc oncogene, which exhibits a nonpaired, reactive guanine at a flanking position of the G-quartetsWe are thankful for the financial support from the Xunta de Galicia (Centro singular de investigación de Galicia accreditation 2019-2022, ED431G 2019/03) and the European Union (European Regional Development Fund – ERDF). We also acknowledge the support given by the Spanish Grant SAF2013-41943-R and SAF2016-76689-R, the Xunta de Galicia (Grants 2015-CP082, ED431C 2017/19,), the Spanish Ministry de Economia y Competitividad (CTQ2017-88648R and RYC-2016-20331), the Generalitat de Cataluña (2017SGR883), the Universitat Rovira i Virgili (2019PFR-URV-B2-02), the Universitat Rovira i Virgili and Banco Santander (2017EXIT-08), and the European Research Council (Advanced Grant No. 340055). M.M.-C. thanks the Ministerio de Economı́a y Competitividad for the Postdoctoral fellowship (IJCI-2014-19326) and the Ministerio de Ciencia e Innovación and Ministerio de Universidades for the Distinguished Researcher contract “Beatriz Galindo” (BEAGAL18/00144). J.R. thanks Xunta de Galicia for her predoctoral fellowshipS
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