214 research outputs found
Thermodynamics of an attractive 2D Fermi gas
Thermodynamic properties of matter are conveniently expressed as functional
relations between variables known as equations of state. Here we experimentally
determine the compressibility, density and pressure equations of state for an
attractive 2D Fermi gas in the normal phase as a function of temperature and
interaction strength. In 2D, interacting gases exhibit qualitatively different
features to those found in 3D. This is evident in the normalized density
equation of state, which peaks at intermediate densities corresponding to the
crossover from classical to quantum behaviour.Comment: Contains minor revision
Seeking languagelessness: maker literacies mindsets to disrupt normative practices
This article challenges an over-reliance on language as the primary means to communicate knowledge by adopting a languagelessness approach to maker pedagogies and maker literacies. Having conducted makerspace and design-based research for some time, we separately and together noticed a productive relationship between wordless relational makerspace and making moments focused on craft, tools, technologies, and materials, and ways that an absence of verbal and written communication opens possibilities within learning environments. After meetings and discussions, we co-wrote the article to examine ways that language-light, even language-free pedagogical spaces allow for a different quality of design work that motivates and fosters innovation. There are three international research projects that serve as research vignettes to investigate the efficacy of languagelessness. The theory foregrounded to anchor and interpret the three vignettes draws from maker literacies research and sociomaterial orientations to knowledge development
Sociomaterial movements of students' engagement in a school's makerspace
This study investigates the sociomaterial movements of student engagement in a school's makerspace. Here, we understand sociomaterial movements as emergent and relational, comprising complex dynamics of agency across students, teachers and materials in situated, culturally framed activities. Our study draws on data comprising 85 hours of video recordings of 9-12-year-old students' (N = 94) engagement in a technology-rich makerspace in a Finnish elementary school. The video data were transcribed and analyzed qualitatively using a multimodal interaction analysis. The sociomaterial movements were found to be displayed across a tension-laden continuum between (1) procedural activity-analysis and reflection; (2) individual activity-collaboration; (3) "doing school"-empowerment; and d) alienation-identification. Together, the study offers a potential approach for investigating and understanding the often overlooked workings of sociomateriality that constitutes students' emergent engagement and learning opportunities in science, technology, engineering and mathematics (STEAM) learning contexts.Peer reviewe
Criteria for 2D kinematics in an interacting Fermi gas
Ultracold Fermi gases subject to tight transverse confinement offer a highly
controllable setting to study the two-dimensional (2D) BCS to
Berezinskii-Kosterlitz-Thouless superfluid crossover. Achieving the 2D regime
requires confining particles to their transverse ground state which presents
challenges in interacting systems. Here, we establish the conditions for an
interacting Fermi gas to behave kinematically 2D. Transverse excitations are
detected by measuring the transverse expansion rate which displays a sudden
increase when the atom number exceeds a critical value signifying a
density driven departure from 2D kinematics. For weak interactions is
set by the aspect ratio of the trap. Close to a Feshbach resonance, however,
the stronger interactions reduce and excitations appear at lower
density.Comment: Replaced with published version, includes supplementary informatio
Teacher interventions in studentsâ collaborative work in a technology-rich educational makerspace
This study reports on an investigation of teacher interventions in students' collaborative work in an educational makerspace. We draw on a qualitative analysis of video data on teacher-student interaction derived from 94 students (aged 9-12) and their teachers in a Finnish school. The results show that the teacher interventions were both student- and teacher-initiated. Three leading teacher intervention strategies were identified, namely authoritative, orchestrating and unleashing which emerged in teacher-student interactions dealing with conceptual, procedural, technological, behavioural and motivational issues. The study demonstrates the demands makerspaces pose for teacher-student interaction, and how moving from authoritative to collaborative interaction requires collective efforts and cultural change.Peer reviewe
Motive-demand dynamics creating a social context for studentsâ learning experiences in a making and design environment
Making and design environments, often referred to as makerspaces, have aroused recent educational interest. These environments typically consist of spaces that support interest-driven engagement in hands-on creative activities with a range of digital artefacts. Although a variety of benefits from participating in making and design activities have been proposed, we currently have limited understanding of studentsâ learning experiences in makerspaces situated in schools. Following Hedegaardsâ conceptualisations, we investigate motive-demand dynamics in studentsâ social activity in a school-based digital making and design environment, âThe FUSE Studioâ. We highlight our findings via vignettes selected from 65 h of video recordings of 94 students (aged between 9 and 12 years old) carrying out activities; the recordings were collected intermittently from an elective course over one semester. Our study illustrates how the studentsâ learning experiences were shaped through tension-laden interplay between the motives and demands of their activity situated across personal, relational and institutional contexts. The findings make visible how established ways of working and being at school interacted and came into tension with the studentsâ motive orientations, thereby limiting and at times transforming the social context of their learning. Our work also demonstrates how the analysis of motive-demand dynamics offers one useful conceptual tool to unpack studentsâ learning experiences in novel learning environments.Peer reviewe
Patterns of longâterm vegetation change vary between different types of semiânatural grasslands in Western and Central Europe
Questions: Has plant species richness in semiânatural grasslands changed over recent decades? Do the temporal trends of habitat specialists differ from those of habitat generalists? Has there been a homogenization of the grassland vegetation?
Location: Different regions in Germany and the UK.
Methods: We conducted a formal metaâanalysis of reâsurvey vegetation studies of semiânatural grasslands. In total, 23 data sets were compiled, spanning up to 75 years between the surveys, including 13 data sets from wet grasslands, six from dry grasslands and four from other grassland types. Edaphic conditions were assessed using mean Ellenberg indicator values for soil moisture, nitrogen and pH. Changes in species richness and environmental variables were evaluated using response ratios.
Results: In most wet grasslands, total species richness declined over time, while habitat specialists almost completely vanished. The number of species losses increased with increasing time between the surveys and were associated with a strong decrease in soil moisture and higher soil nutrient contents. Wet grasslands in nature reserves showed no such changes or even opposite trends. In dry grasslands and other grassland types, total species richness did not consistently change, but the number or proportions of habitat specialists declined. There were also considerable changes in species composition, especially in wet grasslands that often have been converted into intensively managed, highly productive meadows or pastures. We did not find a general homogenization of the vegetation in any of the grassland types.
Conclusions: The results document the widespread deterioration of semiânatural grasslands, especially of those types that can easily be transformed to high production grasslands. The main causes for the loss of grassland specialists are changed management in combination with increased fertilization and nitrogen deposition. Dry grasslands are most resistant to change, but also show a longâterm trend towards an increase in more mesotrophic species
Music-related activities on Facebook
Despite the current prevalence of users performing musical activities on social media, and on Facebook in particular, little research has examined these behaviors from the perspective of consumer psychology. A cross-sectional, convenience sample of 400 participants (Mage = 22.56, SDage = 7.79) completed an online questionnaire. The findings illustrated that the constructs of opinion leadership, innovativeness, and self-efficacy within the consumer psychology literature were associated with performing music-related activities on Facebook, including the active creation/consumption of music content and use of music listening applications. Thus, music activities performed on Facebook have an overt consumer psychological component. These findings indicate that to understand music-related activities on social media, further research should consider psychological variables in explaining this common and economically important activity
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