Light dark matter scattering in outer neutron star crusts

We calculate for the first time the phonon excitation rate in the outer crust of a neutron star due to scattering from light dark matter (LDM) particles gravitationally boosted into the star. We consider dark matter particles in the sub-GeV mass range scattering off a periodic array of nuclei through an effective scalar-vector interaction with nucleons. We find that LDM effects cause a modification of the net number of phonons in the lattice as compared to the standard thermal result. In addition, we estimate the contribution of LDM to the ion-ion thermal conductivity in the outer crust and find that it can be significantly enhanced at large densities. Our results imply that for magnetized neutron stars the LDM-enhanced global conductivity in the outer crust will tend to reduce the anisotropic heat conduction between perpendicular and parallel directions to the magnetic field.Comment: 14 pages, 3 figure

Diffusion of dark matter in a hot and dense nuclear environment

We calculate the mean free path in a hot and dense nuclear environment for a fermionic dark matter particle candidate in the $\sim$GeV mass range interacting with nucleons via scalar and vector effective couplings. We focus on the effects of density and temperature in the nuclear medium in order to evaluate the importance of the final state blocking in the scattering process. We discuss qualitatively possible implications for opacities in stellar nuclear scenarios, where dark matter may be gravitationally accreted.Comment: 17 pages, 7 figure

Evaluating Engagement in Digital Narratives from Facial Data

Engagement researchers indicate that the engagement level of people in a narrative has an influence on people's subsequent story-related attitudes and beliefs, which helps psychologists understand people's social behaviours and personal experience. With the arrival of multimedia, the digital narrative combines multimedia features (e.g. varying images, music and voiceover) with traditional storytelling. Research on digital narratives has been widely used in helping students gain problem-solving and presentation skills as well as supporting child psychologists investigating children's social understanding such as family/peer relationships through completing their digital narratives. However, there is little study on the effect of multimedia features in digital narratives on the engagement level of people. This research focuses on measuring the levels of engagement of people in digital narratives and specifically on understanding the media effect of digital narratives on people's engagement levels. Measurement tools are developed and validated through analyses of facial data from different age groups (children and young adults) in watching stories with different media features of digital narratives. Data sources used in this research include a questionnaire with Smileyometer scale and the observation of each participant's facial behaviours

Putting theory into practice : moving from student identity to teacher identity

As teaching is a highly skilled and complex profession, pre-service teachers&rsquo; need to develop a series of attributes for their practice in relation to pedagogy, content, student learning, classroom management and their ability to engage in reflection. Through reflective narrative, this article seeks to share how a tertiary music educator prepares her generalist primary pre-service teachers to engage, explore and experience music education within the Bachelor of Education (Primary) course at Unnamed University. It also presents one pre-service teacher&rsquo;s experience of teaching music during her school placements in 2009 in what she calls &lsquo;putting theory into practice&rsquo; moving from student identity to teacher identity. Although the &lsquo;hands-on&rsquo; approach to teaching and learning on-campus and when on school placement provide pre-service teachers with knowledge, skills and understanding, the continued support of professional learning is well recognised and will be an ongoing process as pre-service teachers create their own professional identity.<br /

Tourism and community resilience in the Anthropocene:accentuating temporal overtourism

Global tourism growth is unprecedented. Consequently, this has elevated the sector as a key plank for economic development, and its utility is deeply embedded in political, economic and social-ecological discourse. Where the expansion of the sector leverages natural and cultural landscapes, this applies pressure to social and ecological underpinnings that if not reconciled, can become problematic. The way this plays out in Australia’s Shipwreck Coast and the wider Great Ocean Road region, especially the implications for community resilience, is the focus. Emphasis is placed on the vulnerability of peripheral coastal areas to development that withdraws from destination endowments, yet fails to provide commensurate economic yield as a suitable trade-off. This is obvious where tourism intensification has led to concerns about the breach of normative carrying capacities. Temporal overtourism driven by seasonal overcrowding is countenanced as emblematic of tourism in the Anthropocene where focus tends to be largely growth-oriented, with much less attention given to bolstering social-ecological resilience, especially community resilience. At stake is the resilience of regional areas and their communities, who in the absence of garnering commensurate economic returns from tourism expansion find themselves in social and ecological deficit

Recognizing the Potential to Reduce GHG Emissions Through Air Transportation Electrification

California is aggressively moving forward with efforts to deploy zero-emission transportation technology to fight climate change, especially the Greenhouse Gas (GHG) emissions from the high-impact transportation sector. However, to date, the investments California has made with Cap-and-Trade funding have focused on ground transportation and some marine sources and not the aircraft at the over 140 airports in the state. Through a California-focused comprehensive GHG emissions analysis, this research project seeks to determine how RAM using electric/hybrid electric aircraft can provide new high-speed transportation for high-priority passenger and cargo movement within Fresno County and connections to coastal urban centers. Using VISION, a model developed by the Argonne National Laboratory Transportation Systems Assessment Group, the research team identified and compared the emission per mile and emission per passenger mile between different modes of transportation using traditional petroleum fuel and other sustainable alternatives at an individual level and within the context of the transportation sector, by comparing different modes of transportation. With this estimation on hand, it becomes more viable for the state of California and other states, as well as the federal government, to establish guidelines and goals for transportation policies and investments

Overtourism and degrowth:a social movements perspective

Overtourism is a contemporary phenomenon, rapidly evolving and underlined by what is evidently excessive visitation to tourist destinations. This is obvious in the seemingly uncontrolled and unplanned occurrence of urban overtourism in popular destinations and arguably a consequence of unregulated capital accumulation and growth strategies heavily associated with selling cities as tourism commodities. The vested interests of social movements has converged into growing protests against overtourism and associated degrowth campaigns have emerged out of this activism that calls for alternative governance and management measures that eschew touristic monoculture and simplistic economic growth-oriented models. Accordingly, we explore the evolution of the tourism degrowth discourse among social movement activists in Barcelona, and in particular, where this is related to claims associated with overtourism and the extent to which this might be influencing a paradigm shift from ‘tourism growth’ to ‘tourism degrowth’. Methodologically, we draw from an overarching framework that leverages long-term ethnographic research in Barcelona. Here, we employ in-depth semi-structured interviews, participant observations, informal conversations and retrospective evaluation of field diary entries

EBG Common-Mode 20-GHz Microstrip And Stripline Filters: Sensitivity To Design Parameters

In this article, design and characteristics of 20-GHz electromagnetic bandgap (EBG) common-mode (CM) filters for microstrip (MS) and strip line (SL) differential pairs are considered. CM filter notch (resonance) frequency, depth, and width at the-15 dB level are calculated from the mixed-mode S-parameters. The agreement between the measured and modeled S-parameters of the baseline structures validates the models and allows for further numerical experiments. The systematic analysis of the trends for both MS and SL filter characteristics as functions of various geometrical and material design parameters is presented. Sensitivity to various technological features (conductor surface roughness, trapezoid shape of the traces, and line length imbalance) is also analyzed. It is shown that the MS EBG structure is more sensitive and less monotonic to most of the design parameters than those for the SL. This is attributed to the less electromagnetic field containment and more complex mode structure in the MS structures as compared to the SL. Systematic sensitivity analysis allows for an optimal design of the EBG CM notch filters for any printed circuit board layer where a differential pair runs. Though the analysis is presented for 20-GHz EBG filters, most of the trends would be applicable to the filters for the other frequencies

Mismatch In EBG Common-Mode Filters Implemented On PCBs

In this article, impedance mismatch effects on the characteristics of common-mode (CM) electromagnetic bandgap (EBG) filters are studied using three-dimensional (3-D) full-wave numerical simulations. The CM EBG filters considered herein are designed using standard printed circuit board technology and contain either microstrip (MS) differential pairs running above the EBG plane, or strip line (SL) differential pairs running on one of the layers next to the EBG plane. First, the terminations are fixed at 50 Ω, and the effects of the differential line impedance variations on the EBG filter parameters are studied. Overall, the considered variations in the widths of the traces and edge-to-edge separation distances in both the MS and SL structures do not drastically deteriorate the performance of the EBG CM filters. Then impedances of the ports are set different from 50 Ω, and the effects of this mismatch on the baseline SL and MS EBG structures are studied. It is shown that lower port impedances may have significant effect on the characteristics of filters. In addition, baseline EBG filters are cascaded with unmatched four-port load, and this may also deteriorate performance of filters