153 research outputs found

    Community-Focused Resilience, Climate Adaptation, and Sustainability Planning — One in the Same or Distinct Planning Processes?

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    Communities in the United States are increasingly undertaking initiatives aimed to prepare themselves for the impacts of climate change, improve their resilience, and build their sustainability. To achieve these objectives, communities often undertake a planning process resulting in various planning documents - namely, sustainability, climate change adaptation, hazard mitigation, and resilience plans. These documents are integral to communities as they create plans and objectives that help them achieve goals related to climate change, environmental sustainability, and economic development, among other topics. As communities undertake initiatives to simultaneously address these objectives, it is important to understand how the planning processes used may be similar and potentially complementary, or may be distinct and present trade-offs to one another, and to anticipate how this may affect community planning. To explore this issue, as part of the Professional Research Experience Program (PREP) working with researchers at The National Institute of Standards and Technology’s (NIST) Community Resilience Group, we conducted a content analysis of community resilience, climate change adaptation, hazard mitigation, and sustainability planning guides at the community scale. Through identifying the commonalities and differences of these documents, our research aims to improve planning efficiency, foster communication on these topics, and benefit communities.https://orb.binghamton.edu/research_days_posters_2021/1091/thumbnail.jp

    A Variational Principle Based Study of KPP Minimal Front Speeds in Random Shears

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    Variational principle for Kolmogorov-Petrovsky-Piskunov (KPP) minimal front speeds provides an efficient tool for statistical speed analysis, as well as a fast and accurate method for speed computation. A variational principle based analysis is carried out on the ensemble of KPP speeds through spatially stationary random shear flows inside infinite channel domains. In the regime of small root mean square (rms) shear amplitude, the enhancement of the ensemble averaged KPP front speeds is proved to obey the quadratic law under certain shear moment conditions. Similarly, in the large rms amplitude regime, the enhancement follows the linear law. In particular, both laws hold for the Ornstein-Uhlenbeck process in case of two dimensional channels. An asymptotic ensemble averaged speed formula is derived in the small rms regime and is explicit in case of the Ornstein-Uhlenbeck process of the shear. Variational principle based computation agrees with these analytical findings, and allows further study on the speed enhancement distributions as well as the dependence of enhancement on the shear covariance. Direct simulations in the small rms regime suggest quadratic speed enhancement law for non-KPP nonlinearities.Comment: 28 pages, 14 figures update: fixed typos, refined estimates in section

    Nonsteady condensation and evaporation waves

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    We study motion of a phase transition front at a constant temperature between stable and metastable states in fluids with the universal Van der Waals equation of state (which is valid sufficiently close to the fluid's critical point). We focus on a case of relatively large metastability and low viscosity, when it can be shown analytically that no steadily moving phase-transition front exists. Numerically simulating a system of the one-dimensional Navier-Stokes and continuity equations, we find that, in this case, the nonsteady phase-transition front emits acoustic shocks in forward and backward directions. Through this mechanism, the front drops its velocity and eventually comes to a halt. The acoustic shock wave may shuttle, bouncing elastically from the system's edge and strongly inelastically from the phase transition front. Nonsteady rarefaction shock waves appear in the shuttle process, despite the fact that the model does not admit steady rarefaction waves propagating between stationary states. If the viscosity is below a certain threshold, an instability sets in, driving the system into a turbulent state. This work was supported by the Japan Society for Promotion of Science.Comment: revtex text file and four eps files with figures. Physical Review Letters, in pres

    The Thermonuclear Explosion Of Chandrasekhar Mass White Dwarfs

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    The flame born in the deep interior of a white dwarf that becomes a Type Ia supernova is subject to several instabilities. We briefly review these instabilities and the corresponding flame acceleration. We discuss the conditions necessary for each of the currently proposed explosion mechanisms and the attendant uncertainties. A grid of critical masses for detonation in the range 10710^7 - 2×1092 \times 10^9 g cm−3^{-3} is calculated and its sensitivity to composition explored. Prompt detonations are physically improbable and appear unlikely on observational grounds. Simple deflagrations require some means of boosting the flame speed beyond what currently exists in the literature. ``Active turbulent combustion'' and multi-point ignition are presented as two plausible ways of doing this. A deflagration that moves at the ``Sharp-Wheeler'' speed, 0.1gefft0.1 g_{\rm eff} t, is calculated in one dimension and shows that a healthy explosion is possible in a simple deflagration if the front moves with the speed of the fastest floating bubbles. The relevance of the transition to the ``distributed burning regime'' is discussed for delayed detonations. No model emerges without difficulties, but detonation in the distributed regime is plausible, will produce intermediate mass elements, and warrants further study.Comment: 28 pages, 4 figures included, uses aaspp4.sty. Submitted to Ap

    An Exploratory Study into the Factors Impeding Ethical Consumption

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    Although consumers are increasingly engaged with ethical factors when forming opinions about products and making purchase decisions, recent studies have highlighted significant differences between consumers’ intentions to consume ethically, and their actual purchase behaviour. This article contributes to an understanding of this “ethical purchasing gap” through a review of existing literature, and the inductive analysis of focus group discussions. A model is suggested which includes exogenous variables such as moral maturity and age which have been well covered in the literature, together with further impeding factors identified from the focus group discussions. For some consumers, inertia in purchasing behaviour was such that the decision-making process was devoid of ethical considerations. Several manifested their ethical views through post-purchase dissonance and retrospective feelings of guilt. Others displayed a reluctance to consume ethically due to personal constraints, a perceived negative impact on image or quality, or an outright negation of responsibility. Those who expressed a desire to consume ethically often seemed deterred by cynicism, which caused them to question the impact they, as an individual, could achieve. These findings enhance the understanding of ethical consumption decisions and provide a platform for future research in this area

    Finite size effects near the onset of the oscillatory instability

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    A system of two complex Ginzburg - Landau equations is considered that applies at the onset of the oscillatory instability in spatial domains whose size is large (but finite) in one direction; the dependent variables are the slowly modulated complex amplitudes of two counterpropagating wavetrains. In order to obtain a well posed problem, four boundary conditions must be imposed at the boundaries. Two of them were already known, and the other two are first derived in this paper. In the generic case when the group velocity is of order unity, the resulting problem has terms that are not of the same order of magnitude. This fact allows us to consider two distinguished limits and to derive two associated (simpler) sub-models, that are briefly discussed. Our results predict quite a rich variety of complex dynamics that is due to both the modulational instability and finite size effects

    Video meeting signals: experimental evidence for a technique to improve the experience of video conferencing

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    We found evidence from two experiments that a simple set of gestural techniques can improve the experience of online meetings. Video conferencing technology has practical benefits, but psychological costs. It has allowed industry, education and social interactions to continue in some form during the covid-19 lockdowns. But it has left many users feeling fatigued and socially isolated, perhaps because the limitations of video conferencing disrupt users' ability to coordinate interactions and foster social affiliation. Video Meeting Signals (VMSℱ) is a simple technique that uses gestures to overcome some of these limitations. First, we carried out a randomised controlled trial with over 100 students, in which half underwent a short training session in VMS. All participants rated their subjective experience of two weekly seminars, and transcripts were objectively coded for the valence of language used. Compared to controls, students with VMS training rated their personal experience, their feelings toward their seminar group, and their perceived learning outcomes as significantly higher. Also, they were more likely to use positive language and less likely to use negative language. A second, larger experiment replicated the first, and added a condition where groups were given a version of the VMS training but taught to use emoji response buttons rather than gestures to signal the same information. The emoji-trained groups did not experience the same improvement as the VMS groups. By exploiting the specific benefits of gestural communication, VMS has great potential to overcome the psychological problems of group video meetings

    Herbage nutritive value of binary- and multi-species swards relative to single-species swards in intensive silage systems

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    peer-reviewedThe nutritive value of sown binary- and multi-species grassland mixtures may differ from the values expected based on single-species swards of their constituent species. Field plots were established in a split-plot design to assess the nutritive value of binary- and multi-species mixtures compared to single-species swards of three grass species and red clover (RC) (Trifolium pratense L.) managed for intensive silage production. The nutritive value of grass–legume binary mixtures reflected the values of the constituent species grown on their own, and thus may be predicted from monoculture values. The relatively low digestibility (dry matter digestibility [DMD]) and crude protein (CP) content of the Italian ryegrass (Lolium multiflorum L.) sward compared to perennial ryegrass (Lolium perenne L.) and timothy (Phleum pratense L.) suggests that it may have a limited role in binary- or multi-species swards. Herbage nutritive value in the multi-species swards (Mix 1: perennial ryegrass, timothy, RC and white clover [Trifolium repens L.]; Mix 2: perennial ryegrass, timothy, RC, ribwort plantain [Plantago lanceolata L.] and chicory [Cichorium intybus L.] ) appeared to be influenced more by the presence of legumes than herbs. Compared to perennial ryegrass, the multi-species swards had a slower rate of DMD decline prior to Cut 1, but subsequently had lower DMD values at the mid-season harvests. Both multi-species mixtures exhibited DMD, water-soluble carbohydrate (WSC) and CP values that would not have been predicted from their constituent species and thus need to be measured on herbage from field plots growing these mixtures
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