771 research outputs found

    JULES-BE:Representation of bioenergy crops and harvesting in the Joint UK Land Environment Simulator vn5.1

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    We describe developments to the land surface model JULES, allowing for flexible user-prescribed harvest regimes of various perennial bioenergy crops or natural vegetation types. Our aim is to integrate the most useful aspects of dedicated bioenergy models into dynamic global vegetation models, in order that assessment of bioenergy options can benefit from state-of-the-art Earth system modelling. A new plant functional type (PFT) representing Miscanthus is also presented. The Miscanthus PFT fits well with growth parameters observed at a site in Lincolnshire, UK; however, global observed yields of Miscanthus are far more variable than is captured by the model, primarily owing to the model's lack of representation of crop age and establishment time. Global expansion of bioenergy crop areas under a 2 ?C emissions scenario and balanced greenhouse gas mitigation strategy from the IMAGE integrated assessment model (RCP2.6- SSP2) achieves a mean yield of 4.3 billion tonnes of dry matter per year over 2040-2099, around 30 % higher than the biomass availability projected by IMAGE. In addition to perennial grasses, JULES-BE can also be used to represent short-rotation coppicing, residue harvesting from cropland or forestry and rotation forestry

    Solar Cycle Variations In The Electron Heat Flux: Ulysses Observations

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    Solar wind observations by the Ulysses spacecraft now include nearly ten years of continuous ion and electron measurements. In this study, we report detailed measurements of the electron heat flux in the solar wind. In particular, we examine the heat flux measurements for long-term correlations with wave activity and solar wind speed. We find that the average heat flux, when scaled by R2,9to account for variations due to distance from the Sun, is constant and independent of heliographic latitude or solar cycle. We find that during both solar maximum and solar minimum, there is no significant correlation between the magnitude of the electron heat flux and the solar wind speed. Comparison of the electron heat flux data with wave activity indicates that the whistler heat flux instability does not play an important role in limiting the solar wind heat flux

    COVID‑Specific Coercive Control among Emerging Adults Attending College: A Brief Note

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    The COVID-19 pandemic represents a “perfect storm” with regards to risk for intimate partner violence (IPV). Abusive partners may engage in novel forms of coercive control, such as pressuring their partner to engage in activities associated with COVID-19 infection risk (e.g., attend a large gathering). However, no empirical research has focused on COVIDspecific coercive control. The current study sought to evaluate the prevalence of COVID-specific coercive control in a large sample of U.S. college students, as well as its association with other forms of IPV and depression and anxiety. A total of 2,289 undergraduate students attending eight U.S. universities who were currently in a sexual/dating/romantic relationship completed an online survey in Fall 2020 about COVID-specific coercive control, other forms of IPV (psychological, physical, sexual, coercive control) and depression and anxiety symptoms. Overall, 15.5% (n = 355) of students reported experiencing COVID-specific coercive control. Individuals who experienced COVID-specific coercive control were more likely to have experienced all other forms of IPV than those who did not experience COVID-specific coercive control. Further, individuals who experienced COVID-specific coercive control had significantly greater anxiety than individuals who did not experience any form of IPV. Individuals who experienced both COVID-specific coercive control and other forms of IPV had the highest levels of depression and anxiety. COVID-specific coercive control may serve to increase depression and anxiety, particularly if it co-occurs with other forms of IPV. Future work should evaluate the prevalence and long-term impact of coercive control during the COVID-19 pandemic

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    Charge hopping revealed by jitter correlations in the photoluminescence spectra of single CdSe nanocrystals

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    Spectral fluctuations observed in single CdSe/ZnS nanocrystals at 5 K are found to be entirely the result of discrete charge hops in the local environment of the nanocrystal, which occur at a rate comparable to the acquisition time of a single spectrum. We show that intervals between discrete spectral hops introduce a correlation between the successive measurements of the emission wavelength of single CdSe nanocrystals. This correlation can be recovered even in the presence of noise, but is shown to be sensitive to the experimental acquisition time, in good agreement with theory. However, we only find correlations for the smaller of the two nanocrystal sizes studied and discuss this in terms of size-dependent time scales correlated with the amount of excess energy dissipated in the nanocrystal due to hot-carrier relaxation. © 2010 The American Physical Societ

    Learning and interaction in groups with computers: when do ability and gender matter?

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    In the research reported in this paper, we attempt to identify the background and process factors influencing the effectiveness of groupwork with computers in terms of mathematics learning. The research used a multi-site case study design in six schools and involved eight groups of six mixed-sex, mixed-ability pupils (aged 9-12) undertaking three research tasks – two using Logo and one a database. Our findings suggest that, contrary to other recent research, the pupil characteristics of gender and ability have no direct influence on progress in group tasks with computers. However, status effects – pupils' perceptions of gender and ability – do have an effect on the functioning of the group, which in turn can impede progress for all pupils concerned

    Prospectus, February 2, 2000

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    https://spark.parkland.edu/prospectus_2000/1003/thumbnail.jp

    A Process Description of Playing to Live! A Community Psychosocial Arts Program During Ebola

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    From 2014 to 2015, Liberia experienced the largest Ebola epidemic in world history. The impact of this disease was not only physical; it created fear, loss, and trauma throughout the country. This article will describe the process of three phases of a community-based psychosocial expressive arts program, which used theory from the fields of expressive arts therapy to build mental health capacity during and after the epidemic. This article will highlight the background of Ebola virus disease and the Ebola virus disease epidemic, provide an overview of current theory and research for expressive arts therapy and the impact of trauma, describe the process of how the program developed and was implemented, the process of partnering with the community, program components, the two pilot programs, and the large-scale community program. We performed a mixed-methods analysis of the large-scale program’s activity data to evaluate the impact. The results highlight a positive response from the participating children and facilitators. The authors discuss the findings from the results, best practices, and limitations. Additionally, the authors discuss implications and considerations for future programming

    Evaluating the use of biomass energy with carbon capture and storage in low emission scenarios

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    Biomass Energy with Carbon Capture and Storage (BECCS) is heavily relied upon in scenarios of future emissions that are consistent with limiting global mean temperature increase to 1.5 °C or 2 °C above pre-industrial. These temperature limits are defined in the Paris Agreement in order to reduce the risks and impacts of climate change. Here, we explore the use of BECCS technologies in a reference scenario and three low emission scenarios generated by an integrated assessment model (IMAGE). Using these scenarios we investigate the feasibility of key implicit and explicit assumptions about these BECCS technologies, including biomass resource, land use, CO2 storage capacity and carbon capture and storage (CCS) deployment rate. In these scenarios, we find that half of all global CO2 storage required by 2100 occurs in USA, Western Europe, China and India, which is compatible with current estimates of regional CO2 storage capacity. CCS deployment rates in the scenarios are very challenging compared to historical rates of fossil, renewable or nuclear technologies and are entirely dependent on stringent policy action to incentivise CCS. In the scenarios, half of the biomass resource is derived from agricultural and forestry residues and half from dedicated bioenergy crops grown on abandoned agricultural land and expansion into grasslands (i.e. land for forests and food production is protected). Poor governance of the sustainability of bioenergy crop production can significantly limit the amount of CO2 removed by BECCS, through soil carbon loss from direct and indirect land use change. Only one-third of the bioenergy crops are grown in regions associated with more developed governance frameworks. Overall, the scenarios in IMAGE are ambitious but consistent with current relevant literature with respect to assumed biomass resource, land use and CO2 storage capacity

    The negotiation and co-construction of meaning and understanding within a postgraduate online learning community

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    There is an increasing development of courses and course components taught through teaching and learning dialogues online yet there is little secure knowledge regarding the educational quality and outcomes of these dialogues. Drawing on contemporary socio-cultural research, this paper adapts a well-established analytical framework (see Mercer, 1995) that has been developed to understand face to face educational dialogues to the new context of asynchronous electronic conferencing. The work reported is derived from an in-depth case study of a tutorial group of 11 students enrolled on a course within the Open University's MA in Open and Distance Learning. The course was taught on-line to an international cohort of students from wide-ranging academic backgrounds. The analyses of electronic conference archives presented here focus on understanding the students’ on-line collaborative work and the ways in which they constructed meaning, negotiated shared understanding and supported each other in the process of learning at a distance. The implications of the findings for educational practice are considered
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