Lattice strain accommodation and absence of pre-transition phases in Ni50_{50}Mn25+x_{25+x}In25−x_{25-x}

The stoichiometric Ni$_{50}$Mn$_{25}$In$_{25}$ Heusler alloy transforms from a stable ferromagnetic austenitic ground state to an incommensurate modulated martensitic ground state with a progressive replacement of In with Mn without any pre-transition phases. The absence of pre-transition phases like strain glass in Ni$_{50}$Mn$_{25+x}$In$_{25-x}$ alloys is explained to be the ability of the ferromagnetic cubic structure to accommodate the lattice strain caused by atomic size differences of In and Mn atoms. Beyond the critical value of $x$ = 8.75, the alloys undergo martensitic transformation despite the formation of ferromagnetic and antiferromagnetic clusters and the appearance of a super spin glass state.Comment: Appearing in Journal of Physics: Condensed Matte

Supporting Student Learning Toward Twenty-First-Century Skills Through Digital Storytelling

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Participatory service design and community involvement in designing future-ready sustainable learning landscapes

Abstract The United Nations Sustainable Development Goals (SDGs) work as a new agenda for sustainable development globally. Many if not most of the SDGs can be combined with different levels of education. This paper leans on previous work in Sustainable Education Design (SED), which looked at sustainability from its multifaceted angles with a broad global scope. The context of the study is a campus at a research-intensive Finnish university. The methodology entailed participatory service design approaches. For piloting, one classroom was chosen as a test bed. The data consist of workshops, use walks and structured interviews. The analysis started from identifying KPIs of sustainable learning environment creation, after which these were tested against Sustainable Education Design Criteria described in a manual book earlier. The key findings include nine preliminary alternative KPIs that were merged with previous SED criteria and related SDGs. The alternative KPIs were trialled in the test bed environment. These proposed alternative KPIs can be used as indicators for sustainability, innovation and learning during participatory change processes and in evaluating the outcome.</jats:p

Active learning promoting student teachers’ professional competences in Finland and Turkey

This study investigates student teachers’ active learning experiences in teacher education (TE) in Finnish and Turkish contexts and attempts to determine how active learning methods’ impact student teachers’ professional competences. Student teachers (N = 728) assessed their active learning experiences and the professional competences they achieved during TE. Self-regulated and collaborative learning provided the theoretical framework for the active learning measurements. The professional competences included a wide range of teacher responsibilities in schools and society. The data were collected by a survey. A quantitative analysis utilising a regression analysis approach provided strong evidence that active learning has an impact on professional competences. A qualitative analysis further revealed that active knowledge creation with high engagement in learning tasks and a collaborative learning culture were important modes of active learning. While the study focused on two different TE systems, active learning was important in student teachers’ professional development in both contexts. © 2016 Association for Teacher Education in Europe

How approaches to teaching are affected by discipline and teaching context

Two related studies are reported in this article. The first aimed to analyse how academic discipline is related to university teachers' approaches to teaching. The second explored the effects of teaching context on approaches to teaching. The participants of the first study were 204 teachers from the University of Helsinki and the Helsinki School of Economics and Business Administration and 136 teachers from the University of Oxford and Oxford Brookes University who returned university teaching inventories. Thus, altogether there were 340 teachers from a variety of disciplines in Finland and the UK. The second study involved only the Finnish sample. The results showed that there was systematic variation in both student- and teacher-focused dimensions of approaches to teaching across disciplines and across teaching contexts. These results confirm the relational nature of teachers' approaches to teaching and illustrate the need, in using inventories such as the Approaches to Teaching Inventory, to be explicit about the context

On the Importance of Diversity in Re-Sampling for Imbalanced Data and Rare Events in Mortality Risk Models

Surgical risk increases significantly when patients present with comorbid conditions. This has resulted in the creation of numerous risk stratification tools with the objective of formulating associated surgical risk to assist both surgeons and patients in decision-making. The Surgical Outcome Risk Tool (SORT) is one of the tools developed to predict mortality risk throughout the entire perioperative period for major elective in-patient surgeries in the UK. In this study, we enhance the original SORT prediction model (UK SORT) by addressing the class imbalance within the dataset. Our proposed method investigates the application of diversity-based selection on top of common re-sampling techniques to enhance the classifier's capability in detecting minority (ĝ€mortality') events. Diversity amongst training datasets is an essential factor in ensuring re-sampled data keeps an accurate depiction of the minority/majority class region, thereby solving the generalization problem of mainstream sampling approaches. We incorporate the use of the Solow-Polasky measure as a drop-in functionality to evaluate diversity, with the addition of greedy algorithms to identify and discard subsets that share the most similarity. Additionally, through empirical experiments, we prove that the performance of the classifier trained over diversity-based dataset outperforms the original classifier over ten external datasets. Our diversity-based re-sampling method elevates the performance of the UK SORT algorithm by 1.4%

Kinetic arrest of the ferromagnetic state in Mn3_3GaC and Ni2_2MnGa composite mixtures

AbstractThe kinetics of the ferromagnetic to antiferromagnetic transition in Mn$$_3$$ 3 GaC can be arrested and its magnetic properties can be tuned by mixing a small amount ($$\sim$$ ∼ 10%) of Heusler Ni$$_2$$ 2 MnGa to Mn$$_3$$ 3 GaC. A detailed study of magnetic properties of composite mixtures of Mn$$_3$$ 3 GaC and Ni$$_2$$ 2 MnGa with different antiperovskite to Heusler ratio, reveals that the ferromagnetic Ni$$_2$$ 2 MnGa polarizes magnetic spins of the antiperovskite phase by creating a magnetic strain field in its vicinity. The Heusler phase acts as a defect centre whose influence on the magnetic properties of the majority antiperovskite phase progressively diminishes, creating a distribution of transition temperatures. Such strong interaction between the two phases of the mixture allows for tunability and control over the properties of such magneto-structurally transforming materials.</jats:p

Lattice strain accommodation and absence of pre-transition phases in Ni₅₀Mn_25+xIn_25−x

Abstract The stoichiometric Ni50Mn25In25 Heusler alloy transforms from a stable ferromagnetic austenitic ground state to an incommensurate modulated martensitic ground state with a progressive replacement of In with Mn without any pre-transition phases. The absence of pre-transition phases like strain glass in Ni50Mn25+x In25−x alloys is explained to be the ability of the ferromagnetic cubic structure to accommodate the lattice strain caused by atomic size differences of In and Mn atoms. Beyond the critical value of x = 8.75, the alloys undergo martensitic transformation despite the formation of ferromagnetic and antiferromagnetic clusters and the appearance of a super spin glass state.</jats:p