On the search of new design procedures for high performance catalysts we have obtained a very precisely defined surface architecture starting from a particular host structure. In this case, high ...purity La1−xCaxAl1−yNiyO3 (x = 0, 0.1; y = 0.1, 0.2, 0.3) perovskites were chosen, prepared by the citrate method and evaluated in the ethanol steam reforming reaction. The samples were characterized by X-ray diffraction (XRD), specific surface area measurements, X-ray photoelectron spectroscopy (XPS), X-ray absorption near-edge structure (XANES) and extended X-ray adsorption fine structure (EXAFS), temperature-programmed reduction (TPR) and Hydrogen Chemisorption. All the samples presented an excellent catalytic activity and stability. Exceptionally high H2 yield values and low CO and CH4 selectivities were observed. Perovskite without the addition of Ca and with a value of y = 0.2 presented the highest stability during 12 h on stream.
•Perovskites with appropriate textural features were prepared as host structure of catalysts.•Samples presented an excellent stability in the ethanol steam reforming reaction.•High H2 yield and low CO and CH4 selectivities were observed.•LaNi2 catalyst presented the highest stability due to the higher dispersion of Ni.
The worldwide scarcity of psychiatrists makes the identification of the factors associated with the intention to choose this specialty an important issue. This study aims to evaluate the association ...between religious affiliation and the intention to choose psychiatry as a specialty among medical students from 11 Latin American countries. We conducted a cross-sectional, multi-country study that included first- and fifth-year students of 63 medical schools in 11 Latin-American countries between 2011 and 2012. The main outcome and measures were the intention to pursue psychiatry as a specialty over other specialties (yes/no) and religious affiliation (without: atheist/agnostic; with: any religion). A total of 8308 participants were included; 53.6% were women, and the average age was 20.4 (SD = 2.9) years. About 36% were fifth-year students, and 11.8% were not affiliated with any religion. Only 2.6% had the intention to choose psychiatry; the highest proportion of students with the intention to choose psychiatry was among students in Chile (8.1%) and the lowest among students in Mexico (1.1%). After adjusting for demographic, family, academic as well as personal and professional projection variable, we found that those who had no religious affiliation were more likely to report the intention to become a psychiatrist OR: 2.92 (95%CI: 2.14-4.00). There is a strong positive association between not having a religious affiliation and the intention to become a psychiatrist. The possible factors that influence this phenomenon must be evaluated in greater depth, ideally through longitudinal research.
Supported MnCuCe and MnCe mixed oxides catalysts were prepared and evaluated in
n
-hexane combustion reaction. They presented an excellent catalytic activity in total combustion of
n
-hexane. ...Catalysts were characterized by means of XRD, XPS, SBET and TPR techniques. The addition of Cu did not enhance the catalytic activity of MnO
x
/Al
2
O
3
due to the formation of the complete Mn
2
CuO
4
spinel. The presence of cerium favored the formation of manganese oxide species with low crystallinity, with high oxygen mobility and high oxygen vacancies. A higher content of Ce was necessary to obtain catalysts with higher oxidation state of Mn and Ce species.
Graphical Abstract
Este artículo tiene como objetivo reflexionar sobre el quehacer de la investigación alternativa, con el propósito de que la población académica que realiza investigación se interese en comprender los ...diversos significados y perspectivas de la educación superior; promueva la necesidad de vincular el mundo académico con la realidad concreta en permanente diálogo entre visiones y posturas epistemológicas complejas y se apoye en la cooperación y la reflexión, vislumbrando un mundo diverso en el que todos y todas participemos y actuemos en forjar cambios y transformaciones en la realidad. Al mismo tiempo, incorporar la experiencia y práctica investigativa en construcción por el Centro de Investigación en Cultura y Desarrollo (CICDE) de la Vicerrectoría de Investigación de la Universidad Estatal a Distancia de Costa Rica (UNED). En conclusión, la investigación en la Universidad Estatal a Distancia de Costa Rica está en el reto de desarrollar capacidades investigativas alternativas en pro de una academia humanista, crítica, solidaria y hacia la equidad.
A ready-made MnCu catalyst showing a good performance in the combustion of volatile organic compounds has been deposited on FeCrAlloy
® metallic monoliths by means of washcoating. With the aim of ...depositing a homogeneous and well-adhered layer of catalyst on the monoliths, the effects of a pre-coating with colloidal alumina as a primer, the solid concentration in the slurry, the addition of a stabilizer to the slurry, and the immersions number of the monolith in the slurry were studied. The addition of a stabilizer to the slurry was necessary to prevent sedimentation and to achieve reproducible washcoatings. The pre-coating of the monolith with the primer improved the washcoating adherence obtained with one impregnation but a better adherence did not compensate a lower solid load due to a lower surface roughness. A higher amount of deposited material was obtained with the slurry at 35
wt% making two impregnations. The obtained monoliths showed excellent catalytic activity in the combustion of ethyl acetate and toluene. The activity as well as the surface area and pore volume of each monolith increased with the amount of retained solid.
Este artículo es realizado a partir de la investigación "Mujeres en movimientos socioculturales del siglo XXI: un acercamiento a sus realidades en espacios politizados y artísticos", realizada ...durante 2009-2011 y adscrita al Centro de Investigación en Cultura y Desarrollo (CICDE) de la Universidad Estatal a Distancia (UNED, Costa Rica). El propósito de este estudio es señalar y analizar las organizaciones sociales donde participan las mujeres en espacios mixtos, con el fin de revelar y luchar por sus expresiones identitarias para que no sean ignoradas, oprimidas, silenciadas o excluidas, porque sus valores, identidades y subjetividades son producto de las formas de vida de estas mujeres, quienes producen y construyen espacios culturales y políticos. PALABRAS CLAVE: MOVIMIENTOS SOCIALES * RELACIONES DE GÉNERO * MUJERES * IDENTIDAD * SOCIOCULTURAL This article is based on the research "Women in socio-cultural movements in the 20th Century: an approach to their realities in artistic and political spaces", done by the Development and Culture Research Center (CICDE) of the State University to Distance (UNED, Costa Rica), between 2009 and 2011. This article highlights the efforts of women from social organizations to unclose and fight for their identity expressions and avoid being ignored, oppressed, silenced or excluded, because their values, identities and subjectivities that are product of their cultures and different ways of living. KEYWORDS: SOCIAL MOVEMENTS * GENDER APPROACHES * WOMEN * IDENTITY * SOCIAL CULTURAL
Despite the progress in the management of the pandemic caused by COVID-19, it is necessary to continue exploring and explaining how this situation affected the athlete population around the world to ...improve their circumstances and reduce the negative impact of changes in their lifestyle conditions that were necessitated due to the pandemic. The aim of this study was to analyze the moderating influence of physical activity (PA) and dietary habits on the impact of the COVID-19 pandemic experience on sleep quality in elite and amateur athletes.
A total of 1,420 elite (40.1%) and amateur (59.9%) athletes (41% women; 59% men) from 14 different countries participated in a cross-sectional design study. Data were collected using a battery of questionnaires that identified sociodemographic data, sleep quality index, PA levels, dietary habits, and the athletes' perception of their experience during the COVID-19 pandemic. Means and standard deviations were calculated for each variable. The analysis of variances and the correlation between variables were carried out with non-parametric statistics. A simple moderation effect was calculated to analyze the interaction between PA or dietary habits on the perception of the COVID-19 experience effect on sleep quality in elite and amateur athletes.
The PA level of elite athletes was higher than amateur athletes during COVID-19 (
< 0.001). However, the PA level of both categories of athletes was lower during COVID-19 than pre-COVID-19 (
< 0.01). In addition, amateurs had a higher diet quality than elite athletes during the pandemic (
= 0.014). The perception of the COVID-19 experience as controllable was significantly higher (
= 0.020) among elite athletes. In addition, two moderating effects had significant interactions. For amateur athletes, the PA level moderated the effect of controllable COVID-19 experience on sleep quality
= 3.05;
= 0.028, while for elite athletes, the same effect was moderated by dietary habits
= 4.47,
= 0.004.
Elite athletes had different lifestyle behaviors compared to amateurs during the COVID-19 lockdown. Furthermore, the relevance of maintaining high levels of PA for amateurs and good quality dietary habits by elite athletes was noted by the moderating effect that both variables had on the influence of the controllable experience during the COVID-19 pandemic on sleep quality.
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