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

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

Working toward a sustainable future

Keyword: Federal policy, international policy, sustainable development, social responsibility, economic conditions, environmental protection, business, industryCitation: Hecht A., Fiksel J., & Moses M. 2014. Working toward a sustainable future. Sustainability: Science, Practice, & Policy 10(2):65-75. Published online Jan 15, 2014. http://sspp.proquest.com/archives/vol10iss2/communityessay.hecht.htmlIntroductionHow can contemporary society address the complex interaction of environmental, social, and economic forces? What factors are currently limiting the sustainability of business enterprises? How can federal and state agencies break down silos and work together to pursue sustainability? What is the preferred model for business-government collaboration and engagement with civil society and nongovernmental organizations (NGOs)? We raise these questions because in the 21st century all sectors of society must confront the challenge of sustaining economic development while protecting critical environmental resources.In 1970, when the modern environmental movement was coalescing and the United States Environmental Protection Agency (USEPA) was created, environmental protection focused mainly on addressing issues related to industrial emissions and occupational health and safety. Most environmental challenges were highly visible and easy for the public to understand. For instance, on June 22, 1969, an oil slick and debris in the Cuyahoga River in Cleveland caught fire, drawing national attention to environmental problems in Ohio and elsewhere in the United States. Time magazine wrote on August 1, 1970, "Some River! Chocolate-brown, oily, bubbling with subsurface gases, it oozes rather than flows."Congress addressed the obvious problems of air, water, and land pollution in the United States through media-specific environmental legislation. In the late 1960s and early 1970s, there was significant bipartisan popular demand for federal leadership in ameliorating pollution problems (Andrews, 2011). The Clean Air Act of 1970, the Clean Water Act of 1972, the Safe Drinking Water Act of 1974, the Resource Conservation and Recovery Act of 1976, and the Comprehensive Environmental Response, Cleanup, and Liability (Superfund) Act of 1980 yielded great progress in improving the quality of the environment. These initiatives relied on federal regulations that set maximum pollutant limits and heavily fined businesses that did not comply. The success of these laws and subsequent regulations is evident today: our air and water are cleaner, less hazardous waste is produced, and contaminated sites are being remediated. Existing regulations provide a strong "safety net" against the domestic impacts of pollution, although the potential remains for environmental problems to be "exported" across global supply chains.Despite these significant accomplishments, newly emerging pressures are threatening the well-being and resilience of human society and the natural environment, thus jeopardizing economic prosperity. The urgency of dealing with today's problems is evident. Worldwide population growth and urban development, as well as globalization of industrial production, have driven increased consumption of energy, water, materials, and land. The consequences include increased greenhouse-gas emissions, decreased biodiversity, and threats to vital natural resources including water bodies, soils, forests, wetlands, and coral reefs. The Millennium Ecosystem Assessment found that fifteen of 24 global ecosystem services are being degraded or exhausted (Hassan et al. 2005). A study by the Stockholm Center for Resilience suggests that on a planetary scale we have exceeded our "safe operating boundaries" in terms of greenhouse-gas emissions, nitrogen flows, and biodiversity (Rockstrom et al. 2009). The Global Footprint Network has estimated that if current trends continue, by the 2030s, we will need the equivalent of two Earths to support the world's population.

Design And Sensitivity Analysis Of EBG Stripline Common-Mode Filters

Workflow of electromagnetic bandgap (EBG) common-mode (CM) filter design of edge-coupled differential pairs on a printed circuit board (PCB) and sensitivity of its characteristics to variations of geometrical and material parameters are discussed. A number of simple 20-GHz EBG CM notch filters for differential strip line pairs are designed using full-wave numerical electromagnetic modeling, fabricating, and testing. The cases of one and two strip line differential pairs crossing the EBG patches are considered. The modeled and measured mixed-mode S-parameters are analyzed as functions of geometrical parameters, including size and number of EBG patches, gaps between them, geometry and position of signal traces across the EBG patches, and thicknesses of dielectric layers. The agreement between the measured and modeled mixed-mode S-parameters validates the models and allows for further numerical experiments. It is shown that the EBG filter performance depends on various subtle technological features, e.g., conductor surface roughness on metal surfaces; length imbalance on a differential pair; rate of coupling of lines within each differential pair and between the pairs; and some other factors. The systematic analysis of the trends for filter characteristics as functions of various design parameters allows for an optimal design of the CM notch filter