962 research outputs found
Study of creep function determination of two amorphous polymers by indentation technique
When considering polymeric materials for the components design, their behaviour
under external actions (mechanical, temperature, time, etc.) must be known. Thus,
the study of their mechanical properties is essential if these materials are going to
use as structural elements. The traditional mechanical tests, as tensile test or
dynamic mechanical analysis (DMA), are widely used to determining the mechanical
properties of bulk polymers or films. However, when these materials are used as
coatings or when the available component volume is limited, the traditional tests are
not suitable to determining the mechanical behaviour. Depth sensing indentation test
is a technique that allows obtaining the mechanical properties of a component, at
surface level, even for very small samples.
In this work the possibility of using depth sensing indentation technique to
characterize amorphous polymers was explore. The results were compared with
those obtained by DMA
Effects of isothermal oxidation on the local wear behaviour of laser cladded Inconel 625 coatings
Ni-based alloys, such as Inconel superalloys, are characterized by high strength,
excellent fabricability (including joining), and outstanding corrosion resistance.
However, their use is limited by their high cost. Ni-based coatings are used on
carbon steel components in order to increase their service life under extreme
conditions. Laser cladding deposition has emerged as an excellent method for
processing Ni-based coatings. In this work, the evolution of the local wear behaviour
of Inconel 625 laser cladded coatings after high temperature isothermal oxidation
treatments have been investigated.The authors would like to thank the Spanish government CICYT through grants
MAT2010-18916 and MAT2013-41784-R, the Universidad Rey Juan Carlos project
URJC-CM-2010-CET-5550 and the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement number 605207 for financial
support
Chileans facing immigration: Relations between orientations of acculturation, perception of threat and social well-being in the great concepcion
Indexación: Scopus; Scielo; Redalyc.En Chile, el aumento sostenido de la inmigración extranjera ha impactado en
la construcción de nuevas formas de relación social. Si bien los procesos aculturativos han
sido estudiados desde la perspectiva de los inmigrantes por numerosas investigaciones,
los miembros de las sociedades receptoras han recibido menor atención. Este trabajo
tiene como propósito identificar las preferencias de aculturación de N=553 chilenos,
y verificar sus relaciones con la percepción de amenaza y el bienestar social. Contrario
a lo esperado, el individualismo aculturativo se asoció con un menor grado de
amenaza percibida y una mejor evaluación del propio funcionamiento social que el
integracionismo. Estos hallazgos son relacionados con la incorporación de modelos de
ciudadanía promovidos por la ideología neoliberal en el Chile post-dictatorial.In Chile, the sustained increase of migratory flows is producing an important
impact on building new forms of social relations. Acculturation processes have been
studied from immigrant’s perspective by numerous studies, but host majority members
has received less attention from scholars. is study aimed to verify relations between
acculturation preferences of N=553 Chilean participants, their social well-being and
perceived threat. Results showed that, contrary as expected, individualism was positively
linked with better social functioning and less perceived threat than integrationism,
suggesting the impact of neoliberal ideology on post-dictatorial Chilean culture.http://www.redalyc.org/jatsRepo/647/64753989005/index.htm
Neonatal events, such as androgenization and postnatal overfeeding, modify the response to ghrelin
It is currently accepted that ambient, non-genetic factors influence perinatal development and evoke structural and functional changes that may persist throughout life. Overfeeding and androgenization after birth are two of these key factors that could result in "metabolic imprinting" of neuronal circuits early in life and, thereby, increase the body weight homeostatic "set point", stimulate appetite, and result in obesity. Our aim was to determine the influence of these obesogenic factors on the response to ghrelin. We observed the expected orexigenic effect of ghrelin regardless of the nutritional or hormonal manipulations to which the animals were subjected to at early postnatal development and this effect remained intact at later stages of development. In fact, ghrelin responses increased significantly when the animals were subjected to one of the two manipulations, but not when both were combined. An increased response to ghrelin could explain the obese phenotype displayed by individuals with modified perinatal environment.Ministerio de Educacion y CienciaInstituto de Salud Carlos IIIEuropean Community´s Seventh Framework Programm
Risk factors for major adverse cardiovascular events after osteoporotic hip fracture repair surgery
Osteoporotic hip fracture (OHF) is an increasingly frequent age-related pathology, which results in high rates of functional loss and mortality within the first year after surgery. This study assessed whether preoperative levels of brain natriuretic peptide (NT-proBNP) and troponin I were related to early occurrence (30d) of major adverse cardio-vascular events (MACE) after OHF repair surgery. During a 6-month period, perioperative clinical and analytical data from consecutive patients, without known history of cardiovascular disease and undergoing surgery for OHF repair at a single centre, were prospectively collected. MACE was defined as acute myocardial ischaemia or infarction, acute heart failure or cardiovascular death. amongst the 140 patients included, 23 (16.4%) developed postoperative MACE (MACE group) and 117 did not (Control group). Compared to those from control group, patients from MACE group were older, had poorer physical status (ASA III–IV), received preoperative red blood cell transfusion (RBCT) more frequently, presented with lower haemoglobin concentrations and higher NT-proBNP, creatinine and troponin I concentrations. Overall, RBCT requirements and 30d mortality rate were also higher in MACE group. However, in multivariate analysis, only preoperative RBCT, creatinine >1 mg/dL and NT-proBNP >450 pg/mL remained as independent preoperative risks factors for postoperative MACE, while 95% confidence intervals of odds ratios were wide. Though our findings require confirmation in a larger multicentre cohort, identifying risk factors for early postoperative MACE after OHF repair surgery, might facilitate assessing patients’ risk prior to and following surgery, and targeting them the appropriate preventive and/or therapeutic interventions
Potencial paleoecológico de los depósitos orgánicos marinos de Posidonia oceanica
XV lnternational A.P.L.E. Symposium of Palynolog
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