616 research outputs found
Creep fatigue of low-cobalt superalloys: Waspalloy, PM U 700 and wrought U 700
The influence of cobalt content on the high temperature creep fatigue crack initiation resistance of three primary alloys was evaluated. These were Waspalloy, Powder U 700, and Cast U 700, with cobalt contents ranging from 0 up to 17 percent. Waspalloy was studied at 538 C whereas the U 700 was studied at 760 C. Constraints of the program required investigation at a single strain range using diametral strain control. The approach was phenomenological, using standard low cycle fatigue tests involving continuous cycling tension hold cycling, compression hold cycling, and symmetric hold cycling. Cycling in the absence of or between holds was done at 0.5 Hz, whereas holds when introduced lasted 1 minute. The plan was to allocate two specimens to the continuous cycling, and one specimen to each of the hold time conditions. Data was taken to document the nature of the cracking process, the deformation response, and the resistance to cyclic loading to the formation of small cracks and to specimen separation. The influence of cobalt content on creep fatigue resistance was not judged to be very significant based on the results generated. Specific conclusions were that the hold time history dependence of the resistance is as significant as the influence of cobalt content and increased cobalt content does not produce increased creep fatigue resistance on a one to one basis
Application of Anodic Stripping Voltammetry to assess sorption performance of an industrial waste entrapped in alginate beads to remove As(V)
AbstractA solid waste material containing Fe(III) and other metal (hydr)oxides produced in a metal surface treatment industry has been investigated for As(V) removal. In order to facilitate sorbent application, 2% of raw material has been entrapped in calcium alginate gel matrix (2% O-CA).An accurate characterization of the sorption on gel beads was undertaken, considering thermodynamic and kinetic aspects. All experiments were carried out at pH 8, since the maximum As(V) sorption was reached between pH 6 and 9. About isotherms, the best fit was obtained considering the Langmuir model and a capacity of 1.9mg/g was achieved. The kinetic profiles evidenced that a quantitative sorption was obtained within 10h. The 2% O-CA beads were also tested for continuous As(V) removal in a fixed bed column. Experiments were performed at constant flow rate, and varying the inlet As(V) concentration. With a view to design an automatic system for As(V) analysis in the outlet flow, the suitability of applying Anodic Stripping Voltammetry was evaluated: the method resulted appropriated to follow the As(V) content in the outlet solutions of columns with metal inlet concentration <1 mg/L.These results suggested that 2% O-CA beads could be a promising sorbent candidate for As(V) removal
A rigorous analysis of high order electromagnetic invisibility cloaks
There is currently a great deal of interest in the invisibility cloaks
recently proposed by Pendry et al. that are based in the transformation
approach. They obtained their results using first order transformations. In
recent papers Hendi et al. and Cai et al. considered invisibility cloaks with
high order transformations. In this paper we study high order electromagnetic
invisibility cloaks in transformation media obtained by high order
transformations from general anisotropic media. We consider the case where
there is a finite number of spherical cloaks located in different points in
space. We prove that for any incident plane wave, at any frequency, the
scattered wave is identically zero. We also consider the scattering of finite
energy wave packets. We prove that the scattering matrix is the identity, i.e.,
that for any incoming wave packet the outgoing wave packet is the same as the
incoming one. This proves that the invisibility cloaks can not be detected in
any scattering experiment with electromagnetic waves in high order
transformation media, and in particular in the first order transformation media
of Pendry et al. We also prove that the high order invisibility cloaks, as well
as the first order ones, cloak passive and active devices. The cloaked objects
completely decouple from the exterior. Actually, the cloaking outside is
independent of what is inside the cloaked objects. The electromagnetic waves
inside the cloaked objects can not leave the concealed regions and viceversa,
the electromagnetic waves outside the cloaked objects can not go inside the
concealed regions. As we prove our results for media that are obtained by
transformation from general anisotropic materials, we prove that it is possible
to cloak objects inside general crystals.Comment: The final version is now published in Journal of Physics A:
Mathematical and Theoretical, vol 41 (2008) 065207 (21 pp). Included in
IOP-Selec
FNDC5 is produced in the stomach and associated to body composition
The fibronectin type III domain-containing protein 5 (FNDC5) discovered in 2002 has recently gained attention due to its potential role in protecting against obesity. In rat, no data exist regarding FNDC5 production and regulation in the stomach. The aim of the present work was to determine the expression of FNDC5 in the rat stomach and its potential regulation by body composition. The present data shows FNDC5 gene expression in the gastric mucosa. Immunohistochemical studies found FNDC5 immunopositivity in chief cells of gastric tissue. By the use of three different antibodies FNDC5 was found expressed in gastric mucosa and secreted by the stomach. The rate of gastric FNDC5 secretion parallels the circulating levels of FNDC5. The body fat mass increase after intervention with high fat diet coincided with a decrease in the secretion of FNDC5 from the stomach and a diminution in the FNDC5 circulating levels. In summary, the present data shows, for the first time, the expression of FNDC5 in the stomach of rats and its regulation by body composition, suggesting a potential role of gastric FNDC5 in energy homeostasishis work has been supported by grants from Instituto de Salud Carlos III (PI1202021 and PI15/01272) cofounded by FEDER, Xunta de Galicia (10 PXIB 918 273PR) and Fundación Mutua Madrileña. SB-F is funded by Xunta de Galicia and Universidade de Santiago de Compostela, CF by IDIS (Instituto de Investigación Sanitaria de Santiago de Compostela), CC by Ciber obn and OA-M is funded by the ISCIII/SERGAS thought a research contract “Sara Borrell” (CD14/00091). MP is funded by ISCIII/SERGAS through a research contract “Miguel Servet II”. LMS is a SERGAS-I3SNS researcher. Centro de Investigacion Biomedica en Red Fisiopatología de la Obesidad y Nutrición (CIBERobn) is a iniciative of the Instituto de Salud Carlos III (ISCIII) of Spain which is supported by FEDER fundsS
Virology, Pathology, and Clinical Manifestations of West Nile Virus Disease
Virologic characteristics of WNV likely interact with host factors in the pathogenesis of fever, meningitis, encephalitis, and flaccid paralysis
Evaluation of the Predictive Ability, Environmental Regulation and Pharmacogenetics Utility of a BMI-Predisposing Genetic Risk Score during Childhood and Puberty
The authors would like to thank the Spanish children and parents who participated in
the study.Polygenetic risk scores (pGRSs) consisting of adult body mass index (BMI) genetic
variants have been widely associated with obesity in children populations. The implication of
such obesity pGRSs in the development of cardio-metabolic alterations during childhood as well
as their utility for the clinical prediction of pubertal obesity outcomes has been barely investigated
otherwise. In the present study, we evaluated the utility of an adult BMI predisposing pGRS for the
prediction and pharmacological management of obesity in Spanish children, further investigating
its implication in the appearance of cardio-metabolic alterations. For that purpose, we counted
on genetics data from three well-characterized children populations (composed of 574, 96 and 124
individuals), following both cross-sectional and longitudinal designs, expanding childhood and
puberty. As a result, we demonstrated that the pGRS is strongly associated with childhood BMI
Z-Score (B = 1.56, SE = 0.27 and p-value = 1.90 × 10−8
), and that could be used as a good predictor of
obesity longitudinal trajectories during puberty. On the other hand, we showed that the pGRS is not
associated with cardio-metabolic comorbidities in children and that certain environmental factors
interact with the genetic predisposition to the disease. Finally, according to the results derived from a
weight-reduction metformin intervention in children with obesity, we discarded the utility of the
pGRS as a pharmacogenetics marker of metformin response.Plan Nacional de Investigacion Cientifica, Desarrollo e Innovacion Tecnologica (I + D + I), Instituto de Salud Carlos III-Health Research Funding (FONDOS FEDER)
PI1102042
PI1102059
PI1601301
PI1600871Spanish Ministry of Health, Social and Equality, General Department for Pharmacy and Health Products
EC10-243
EC10-056
EC10-281
EC10-227Regional Government of Andalusia ("Plan Andaluz de investigacion, desarrollo e innovacion (2018)")
P18-RT-2248Mapfre Foundation ("Research grants by Ignacio H. de Larramendi 2017")Instituto de Salud Carlos III
IFI17/0004
On stability of discretizations of the Helmholtz equation (extended version)
We review the stability properties of several discretizations of the
Helmholtz equation at large wavenumbers. For a model problem in a polygon, a
complete -explicit stability (including -explicit stability of the
continuous problem) and convergence theory for high order finite element
methods is developed. In particular, quasi-optimality is shown for a fixed
number of degrees of freedom per wavelength if the mesh size and the
approximation order are selected such that is sufficiently small and
, and, additionally, appropriate mesh refinement is used near
the vertices. We also review the stability properties of two classes of
numerical schemes that use piecewise solutions of the homogeneous Helmholtz
equation, namely, Least Squares methods and Discontinuous Galerkin (DG)
methods. The latter includes the Ultra Weak Variational Formulation
Does fish larval dispersal differ between high and low latitudes?
Author Posting. © The Author(s), 2013. This is the author's version of the work. It is posted here by permission of The Royal Society for personal use, not for redistribution. The definitive version was published in Proceedings of the Royal Society B Biological Sciences 280 (2013): 20130327, doi:10.1098/rspb.2013.0327.Several factors lead to expectations that the scale of larval dispersal and population
connectivity of marine animals differs with latitude. We examine this expectation for
demersal shorefishes, including relevant mechanisms, assumptions, and evidence.
We explore latitudinal differences in: 1) biological (e.g., species composition,
spawning mode, pelagic larval duration (PLD)), 2) physical (e.g., water movement,
habitat fragmentation), and 3) biophysical factors (primarily temperature, which could
strongly affect development, swimming ability, or feeding). Latitudinal differences
exist in taxonomic composition, habitat fragmentation, temperature, and larval
swimming, and each could influence larval dispersal. Nevertheless, clear evidence
for latitudinal differences in larval dispersal at the level of broad faunas is lacking.
For example, PLD is strongly influenced by taxon, habitat, and geographic region,
but no independent latitudinal trend is present in published PLD values. Any trends
in larval dispersal may be obscured by a lack of appropriate information, or use of
‘off the shelf’ information that is biased with regard to the species assemblages in
areas of concern. Biases may also be introduced from latitudinal differences in taxa
or spawning modes, as well as limited latitudinal sampling. We suggest research to
make progress on the question of latitudinal trends in larval dispersal.TK was supported by the Norwegian Research Council through project
MENUII #190286. JML was supported by ARC Discovery Grant DP110100695.
JEC and RRW were supported by the Partnership for the Interdisciplinary Study of
Coastal Oceans, funded by The David and Lucille Packard Foundation and the
Gordon and Betty Moore Foundation.2014-03-2
Explanation and elaboration of the SQUIRE (Standards for Quality Improvement Reporting Excellence) Guidelines, V.2.0: examples of SQUIRE elements in the healthcare improvement literature
Since its publication in 2008, SQUIRE (Standards for Quality Improvement Reporting Excellence) has contributed to the completeness and transparency of reporting of quality improvement work, providing guidance to authors and reviewers of reports on healthcare improvement work. In the interim, enormous growth has occurred in understanding factors that influence the success, and failure, of healthcare improvement efforts. Progress has been particularly strong in three areas: the understanding of the theoretical basis for improvement work; the impact of contextual factors on outcomes; and the development of methodologies for studying improvement work. Consequently, there is now a need to revise the original publication guidelines. To reflect the breadth of knowledge and experience in the field, we solicited input from a wide variety of authors, editors and improvement professionals during the guideline revision process. This Explanation and Elaboration document (E&E) is a companion to the revised SQUIRE guidelines, SQUIRE 2.0. The product of collaboration by an international and interprofessional group of authors, this document provides examples from the published literature, and an explanation of how each reflects the intent of a specific item in SQUIRE. The purpose of the guidelines is to assist authors in writing clearly, precisely and completely about systematic efforts to improve the quality, safety and value of healthcare services. Authors can explore the SQUIRE statement, this E&E and related documents in detail at http://www.squire-statement.org
- …