104 research outputs found
Precipitation and grain growth modelling in Ti-Nb microalloyed steels
Peer ReviewedPostprint (author's final draft
Atribuciones causales en lectura en alumnos chilenos de educación básica. Análisis en función del sexo
The theory of attributions becomes important insofar as it is related to motivation. From a motivational perspective, the attributions made by students are directly related to self-concept, self-esteem and learning goals. The objective of this study was to establish if there are differences between causal attributions based on sex. To carry out the study, there were 1702 students from 20 Ñuble centers in Chile, 905 children (53.2%) and 797 girls (46.8%) between the ages of 10 and 12 (M = 10.06; SD = 1.05). . The evaluation was carried out with the Sydney Attribution Scale (SAS) which measures two academic areas on which attributions are carried out (Reading and Mathematics), two hypothetical results (success and failure) and three types of causes (capacity, effort and external causes). The data were analyzed from the calculation of differences in means and p tests to determine the presence of significant statistical differences. The results showed that girls attribute their successes more to ability, effort and external causes than children, as well as that children attribute their failures more to lack of effort. From the results it can be reported that there are statistically significant differences between the attributions of boys and girls. Being girls, who by the type of attributions, are more in danger in their self-esteem and children more in their expectations.La teoría de las atribuciones cobra importancia en tanto se relaciona con la motivación. Desde una perspectiva motivacional, las atribuciones que realizan los estudiantes se relacionan directamente con el autoconcepto, la autoestima y las metas de aprendizaje. El objetivo de este estudio fue establecer si existen diferencias entre las atribuciones causales en función del sexo. Para realizar el estudio se contó con 1702 alumnos de 20 centros de Ñuble en Chile, 905 niños (53,2%) y 797 niñas (46,8%) de edades entre 10 y 12 años (M = 10.06; DE= 1.05). La evaluación se realizó con la Sydney Attribution Scale (SAS) que mide dos áreas académicas sobre las que se realizan atribuciones (Lectura y Matemáticas), dos resultados hipotéticos (éxito y fracaso) y tres tipos de causas (capacidad, esfuerzo y causas externas). Los datos fueron analizados a partir del cálculo de diferencias de medias y pruebas p para determinar la presencia de diferencias estadísticas significativas. Los resultados mostraron que las niñas atribuyen más sus éxitos a la capacidad, al esfuerzo y a causas externas que los niños, así como también que los niños atribuyen más sus fracasos a la falta de esfuerzo. De los resultados se puede informar que existen diferencias estadísticamente significativas entre las atribuciones de niños y niñas. Siendo las niñas, quienes, por el tipo de atribuciones, peligran más en su autoestima y los niños más en sus expectativas
Design and development of complex phase steels with improved combination of strength and stretch-flangeability
This study presents the design and development of a hot-rolled bainitic steel, presenting a good combination of strength and stretch-flangeability, for automotive applications. Ti, Nb, and Mo were added in the steel composition in order to control austenite grain sizes, enhance precipitation hardening, and promote the formation of bainite. This study focuses on the effect of process parameters on final microstructures and mechanical properties. These parameters are the finishing rolling temperature, which conditions the austenite microstructure before its decomposition, and the coiling temperature, which conditions the nature and morphology of the ferritic phases transformed. A preliminary study allowed to determine the austenite grain growth behavior during reheating, the recrystallization kinetics, and the continuous cooling transformation curves of the studied steel. Then, a first set of parameters was tested at a semi-industrial scale, which confirmed that the best elongation properties were obtained for homogeneous bainitic lath/granular microstructures, that can be produced by choosing a coiling temperature of 500 °C . When choosing those parameters for the final industrial trial, the microstructure obtained consisted of a homogeneous lath/granular bainite mixture that presented a Ultimate Tensile Strength of 830 MPa and a Hole Expansion Ratio exceeding 70%.Peer ReviewedPostprint (published version
Measurement of galactosyl-deficient IgA1 by the monoclonal antibody KM55 contributes to predicting patients with IgA nephropathy with high risk of long-term progression
Backgroundandobjective:About25%ofpatientswithIgAnephropathy(IgAN)progresstostage5chronickidneydisease(CKD)afteryearsofevolution.Varioustoolshavebeendevelopedinrecentyearsdesignedtopredictwhichofthepatientswillhadpooreroutcomes.Thevalueofcirculatinggalactosyl-deficientIgA1(Gd-IgA1)hasbeenrelatedtoaworseevolutionofIgANinseveralstudies.TherearealsosomepublicationsthatrelatehigherAPRILvalueswithaworseevolution.Recently,anewmethodhasbeendevelopedthatallowsmeasuringthevalueofcirculatingGd-IgA1inasimplerwaythanthosepreviouslyavailable.TheobjectiveofthisstudyistoanalyzetheinfluenceofcirculatingGd-IgA1,measuredbythismethod,ontheprogressionofIgAN.Materialsandmethods:Forty-ninepatientswithadiagnosisofIgANdemonstratedbyrenalbiopsywereselectedinourcenter,withouthavingreceivedpriorimmunosuppressivetreat-ment,forwhomfrozenserumwasavailable.Themedianfollow-upwas4years.Gd-IgA1wasmeasuredbylectin-independentELISAwiththemonoclonalantibodyKM55(IgA1kitCat.No.30111694.IBLInt.,Hamburg,Germany).Likewise,APRILlevelswerealsomeasuredinthesepatients.Results:19(38.8%)patientsreachedstage5CKD.ThefourthquartileofcirculatingGd-IgA1wasrelatedtoahighercumulativeriskofreachingstage5CKDintheKaplan?Meieranalysis(riskatthe5thyear39.4%vs.24.3%,logrankp=0.019).TheGd-IgA1valuewasrelatedto anincreasedriskofCKDstage5(HR1.147,95%CI1.035?1.270,p=0.009),regardlessofglomerularfiltrationrate,proteinuria,thepercentageofsclerosedglomeruliandthevalueofsegmentalsclerosis.WedidnotfindsignificantdifferencesintheAPRILvalues.Conclusions:ThevalueofcirculatingGd-IgA1measuredbythemonoclonalantibodyKM55isrelatedtoaworseevolutionofpatientswithIgANindependentlyofothervariables,soitcouldbeincludedinthestudyofpatientstoimprovethepredictionoftheriskofdiseaseprogression
Aprendizaje Servicio e Innovación Social desde la Universidad
El Aprendizaje Servicio es una estrategia docente necesaria para el desarrollo de iniciativas de emprendimiento e innovación social, que partan desde la Universidad, y que se puedan incorporar en las diferentes áreas de conocimiento de la UC
Creación de un cibermedio sobre periodismo: "Académica_mente”
Depto. de Periodismo y Comunicación GlobalDepto. de Periodismo y Nuevos MediosFac. de Ciencias de la InformaciónFALSEsubmitte
Structure and Properties of Reactively Extruded Opaque Post-Consumer Recycled PET
The recyclability of opaque PET, which contains TiO2 nanoparticles, has not been as well-studied as that of transparent PET. The objective of this work is to recycle post-consumer opaque PET through reactive extrusion with Joncryl. The effect of the reactive extrusion process on the molecular structure and on the thermal/mechanical/rheological properties of recycling post-consumer opaque PET (r-PET) has been analyzed. A 1% w/w Joncryl addition caused a moderate increase in the molecular weight. A moderate increase in chain length could not explain a decrease in the overall crystallization rate. This result is probably due to the presence of branches interrupting the crystallizable sequences in reactive extruded r-PET (REX-r-PET). A rheological investigation performed by SAOS/LAOS/elongational studies detected important structural modifications in REX-r-PET with respect to linear r-PET or a reference virgin PET. REX-r-PET is characterized by a slow relaxation process with enlarged elastic behaviors that are characteristic of a long-chain branched material. The mechanical properties of REX-r-PET increased because of the addition of the chain extender without a significant loss of elongation at the break. The reactive extrusion process is a suitable way to recycle opaque PET into a material with enhanced rheological properties (thanks to the production of a chain extension and long-chain branches) with mechanical properties that are comparable to those of a typical virgin PET sample.We would like to acknowledge funding by the EU Interreg H2020 program through project POCTEFA EFA329/19. This work also received funding from the Basque Government, grant IT1309-19
Implementation of FAIR principles in the IPCC: the WGI AR6 Atlas repository
The Sixth Assessment Report (AR6) of the Intergovernmental Panel on Climate Change (IPCC) has adopted the FAIR Guiding Principles. We present the Atlas chapter of Working Group I (WGI) as a test case. We describe the application of the FAIR principles in the Atlas, the challenges faced during its implementation, and those that remain for the future. We introduce the open source repository resulting from this process, including coding (e.g., annotated Jupyter notebooks), data provenance, and some aggregated datasets used in some figures in the Atlas chapter and its interactive companion (the Interactive Atlas), open to scrutiny by the scientific community and the general public. We describe the informal pilot review conducted on this repository to gather recommendations that led to significant improvements. Finally, a working example illustrates the re-use of the repository resources to produce customized regional information, extending the Interactive Atlas products and running the code interactively in a web browser using Jupyter notebooks.Peer reviewe
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