A DFT+U study of the structural, electronic, magnetic, and mechanical properties of cubic and orthorhombic SmCoO3

SmCoO3 is a perovskite material that has gained attention as a potential substitute for La1−xSrxMnO3−d as a solid oxide fuel cell cathode. However, a number of properties have remained unknown due to the complexity of the material. For example, we know from experimental evidence that this perovskite exists in two different crystal structures, cubic and orthorhombic, and that the cobalt ion changes its spin state at high temperatures, leading to a semiconductor-to-metal transition. However, little is known about the precise magnetic structure that causes the metallic behavior or the spin state of the Co centers at high temperature. Here, we therefore present a systematic DFT+U study of the magnetic properties of SmCoO3 in order to determine what magnetic ordering is the one exhibited by the metallic phase at different temperatures. Similarly, mechanical properties are difficult to measure experimentally, which is why there is a lack of data for the two different phases of SmCoO3. Taking advantage of our DFT calculations, we have determined the mechanical properties from our calculated elastic constants, finding that both polymorphs exhibit similar ductility and brittleness, but that the cubic structure is harder than the orthorhombic phase

Local structure change evidenced by temperature-dependent elastic measurements: Case study on Bi1/2Na1/2TiO3-based lead-free relaxor piezoceramics

The temperature-dependent Young's modulus Y(T) of the lead-free piezoceramics of 0.8Bi(1/2)Na(1/2)TiO(3)-0.2Bi(1/2)K(1/2)TiO(3) (20BKT) and 0.96(0.8Bi(1/2)Na(1/2)TiO(3)-0.2Bi(1/2)K(1/2)TiO(3))-0.04 BiZn1/2Ti1/2O3 (4BZT) is measured with the impulse excitation technique and contrasted with corresponding dielectric and structural data. While the dielectric properties suggest a phase transition, the high resolution XRD patterns remain virtually unchanged from room temperature up to high temperatures, confirming no change in their long-range order. In contrast, the elastic properties indicate a broad and diffuse ferroelastic transition denoted by a minimum in Y(T). By analogy to the elastic and dielectric data of PbZrxTi1-xO3 and PLZT, it is concluded that 20BKT and 4BZT are relaxors with polar nanoregions embedded in a metrically cubic matrix. Interestingly, no indication for the freezing temperature was reflected in any of the employed measurement techniques. From the saturation of Y(T), it is suggested that the Burns temperature may be approximated as 700 degrees C. Moreover, it is found that the modification with the ternary end-member BiZn1/2Ti1/2O3 results in an increase in Young's modulus. A comparison with the Bi1/2Na1/2TiO3-BaTiO3-K0.5Na0.5NbO3 yields the same results.open0

Values - reviewing the construct and drawing implications for values work in organisation and leadership. Kap. 2

I: H.Askeland, G. Espedal, B. Jelstad Løvaas & S. Sirris (Eds.), Understanding values work : Institutional perspectives in organizations and leadershipThis chapter outlines the trajectory of values, particularly within streams of organisational institutionalism, in order to analyse its application to values work in organisation and leadership. Conveying a frame for discussing values work, it aims at clarifying how to conceptualise the term values. Discussing classic and recent contributions, the chapter proposes seeing values as individual and collective conceptions of desirable trans-situational behaviours, objectives and ideals, serving to guide or valuate practice. Despite being an essential part of defining organisational institutionalism, and its sub-streams, values are seldom explicated. Utilising values in organisational and leadership research requires attention to their situatedness in contexts, and this chapter argues they are salient to organisations operating in pluralistic institutional environment. Studying values work, attention should be given to who and how such work is performed.publishedVersio

The Network Structure of Childhood Psychopathology in International Adoptees

International adoptees are at an increased risk of emotional and behavioral problems, especially those who are adopted at an older age. We took a new approach in our study of the network structure and predictability of emotional and behavioral problems in internationally adopted children in Finland. Our sample was from the on-going adoption study and comprised 778 internationally adopted children (387 boys and 391 girls, mean age 10.5 (SD 3.4) years). Networks were estimated using Gaussian graphical models and lasso regularization for all the children, and separately for those who were adopted at different ages. The results showed that anxiety/depressive symptoms, social problems, and aggressiveness were the most central symptom domains. Somatic symptoms were the least central and had the weakest effect on the other domains. Similarly, aggressiveness, social problems, and attention problems were high in terms of predictability (73-65%), whereas internalizing problems were relatively low (28-56%). There were clear but local age-group differences in network structure, symptom centrality, and predictability. According to our findings, network models provide important additional information about the centrality and predictability of specific symptom domains, and thus may facilitate targeted interventions among international adoptees.Peer reviewe

Study of the structure and mechanical properties in 8 mol% yttria-stabilized zirconia coating manufactured by suspension plasma spraying

RESUMEN: El estudio de recubrimientos nanoestructurados fabricados mediante proyección térmica ha generado un gran interés en las últimas dos décadas debido a su considerable mejora en sus propiedades sobre todo en las propiedades físicas y mecánicas. Esta mejora resulta de reducir los tamaños de grano de su materia prima a escalas de 100 a 1000 veces más bajas comparadas con los recubrimientos convencionales microestructurados. Así, estos recubrimientos con estructuras a nivel nano y/o submicrométrica están empezando a ser usados en la industria gracias a sus sobresalientes propiedades y es fundamental el estudio de sus propiedades mecánicas para determinadas aplicaciones. En la actualidad, la indentación es la principal técnica de caracterización de recubrimientos y películas delgadas, a pesar de estar altamente influenciada por los defectos propios del recubrimiento en la vecindad de la indentación. La nanoindentación y la microindentación se presentan como la mejor opción para evaluar el comportamiento mecánico de estos recubrimientos nanoestructurados. Por esta razón, en este trabajo se analizó el efecto de la estructura de un recubrimiento de circona estabilizada con 8% en mol de itria (8YSZ) elaborado por proyección térmica por plasma a partir de suspensiones nanométricas (SPS) y su relación con sus propiedades mecánicas (dureza y módulo de elasticidad) medidas por las técnicas de nanoindentación y microindentación. El análisis de la estructura de la sección transversal mostró que el recubrimiento exhibe una estructura bimodal, la cual está compuesta por una zona con partículas nanométricas semifundidas (ZS) y lamelas con mayor grado de fusión (ZF). Los ensayos de nanoindentación mostraron una distribución de Weibull bimodal de sus propiedades mecánicas, la cual característica de este tipo de recubrimientos; mientras que la dureza (HV) y el módulo de elasticidad evaluados por microindentación, presentaron una distribución monomodal. Estos resultados de microindentación estuvieron influenciados por el área de contacto en las zonas indentadas en la estructura bimodal del recubrimiento. Palabras clave: Recubrimiento por plasma a partir de suspensiones (SPS), estructura, indentación, Distribución Weibull, recubrimiento 8YSZ.ABSTRACT: The study of nanostructured coatings manufactured by thermal spraying has generated a great interest in the last two decades due to their considerable improved properties especially in the physical and mechanical properties. This improvement is to reduce grain sizes of their raw materials at scales of 100-1000 times lower compared to conventional coatings (microstructured). Thus, these coatings structured at the nano and sub micrometric scale start to be used in the industrial applications and, it is essential to study their mechanical properties for certain applications. Currently, the indentation is the main technique for characterizing thin films and coatings, despite being highly influenced by the defects of the coating in the vicinity of the indentation. Nanoindentation and microindentation is presented as the best option for evaluate the mechanical behavior of nanostructured coatings. For this reason, in this work the study of the effect of the structure of the 8 mol% yttria-stabilised zirconia coating (8YSZ) manufactured by suspension plasma spraying (SPS) and the relationship with its mechanical properties (hardness and elastic modulus) measures for nanoindentation and microindentation techniques was analyzed. Analysis of the structure of the cross section of coating exhibit a bimodal structure, which is composed by a zone with semi-molten nanoparticles (ZS) and lamellaes with a higher grade of fusion (ZF). Nanoindentation tests showed a bimodal Weibull distribution of the mechanical properties (hardness and elastic modulus) which is related to the two zones (ZF and ZS) present in the coat-ing, while hardness (HV) and elastic modulus measured by microhardness, showed a monomodal distribu-tion. These results of microhardness were influenced by the contact area of the indentation in zones com-posed of the bimodal structure of the YSZ coating. Keywords: Suspension plasma spraying (SPS), structure, indentation, Weibull distribution, 8YSZ coating

ADVANCE integrated group intervention to address both substance use and intimate partner abuse perpetration by men in substance use treatment: a feasibility randomised controlled trial

Background: Substance use is a risk factor for intimate partner abuse (IPA) perpetration. Delivering perpetrator interventions concurrently with substance use treatment shows promise. Methods: The feasibility of conducting an efficacy and cost-effectiveness trial of the ADVANCE 16-week intervention to reduce IPA by men in substance use treatment was explored. A multicentre, parallel group individually randomised controlled feasibility trial and formative evaluation was conducted. Over three temporal cycles, 104 men who had perpetrated IPA towards a female (ex) partner in the past year were randomly allocated to receive the ADVANCE intervention + substance use treatment as usual (TAU) (n = 54) or TAU only (n = 50) and assessed 16-weeks post-randomisation. Participants’ (ex) partners were offered support and 27 provided outcome data. Thirty-one staff and 12 men who attended the intervention participated in focus groups or interviews that were analysed using the framework approach. Pre-specified criteria assessed the feasibility of progression to a definitive trial: 1) ≥ 60% of eligible male participants recruited; 2) intervention acceptable to staff and male participants; 3) ≥ 70% of participants followed-up and 4) levels of substance use and 5) IPA perpetrated by men in the intervention arm did not increase from average baseline level at 16-weeks post-randomisation. Results: 70.7% (104/147) of eligible men were recruited. The formative evaluation confirmed the intervention’s acceptability. Therapeutic alliance and session satisfaction were rated highly. The overall median rate of intervention session attendance (of 14 compulsory sessions) was 28.6% (range 14.3–64.3% by the third cycle). 49.0% (51/104) of men and 63.0% (17/27) of their (ex) partners were followed-up 16-weeks post-randomisation. This increased to 100% of men and women by cycle three. At follow-up, neither substance use nor IPA perpetration had worsened for men in the intervention arm. Conclusions: It was feasible to deliver the ADVANCE intervention in substance use treatment services, although it proved difficult to collect data from female (ex)partners. While some progression criteria were met, others were not, although improvements were demonstrated by the third cycle. Lessons learned will be implemented into the study design for a definitive trial of the ADVANCE intervention