146 research outputs found

    A methodology for the environmental assessment of advanced coal extraction systems

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    Procedures developed to identify and assess potential environment impacts of advanced mining technology as it moves from a generic concept to a more systems definition are described. Two levels of assessment are defined in terms of the design stage of the technology being evaluated. The first level of analysis is appropriate to a conceptual design. At this level it is assumed that each mining process has known and potential environmental impacts that are generic to each mining activity. By using this assumption, potential environmental impacts can be identified for new mining systems. When two or more systems have been assessed, they can be evaluated comparing potential environmental impacts. At the preliminary stage of design, a systems performance can be assessed again with more precision. At this level of systems definition, potential environmental impacts can be analyzed and their significane determined in a manner to facilitate comparisons between systems. At each level of analysis, suggestions calculated to help the designer mitigate potentially harmful impacts are provided

    A crystallographic phase transition within the magnetically ordered state of Ce_2Fe_17

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    X-ray diffraction experiments were performed on polycrystalline and single-crystal specimens of Ce2_{2}Fe17_{17} at temperatures between 10 K and 300 K. Below TtT_{\mathrm{t}} = 118±\pm2 K, additional weak superstructure reflections were observed in the antiferromagnetically ordered state. The superstructure can be described by a doubling of the chemical unit cell along the c\mathbf{c} direction in hexagonal notation with the same space group R3ˉmR \bar{3} m as the room-temperature structure. The additional antiferromagnetic satellite reflections observed in earlier neutron diffraction experiments can be conclusively related to the appearance of this superstructure.Comment: 8 pages, figures, submitted for publication in Phys. Rev.

    Strong dispersive coupling between a mechanical resonator and a fluxonium superconducting qubit

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    We demonstrate strong dispersive coupling between a fluxonium superconducting qubit and a 690 megahertz mechanical oscillator, extending the reach of circuit quantum acousto-dynamics (cQAD) experiments into a new range of frequencies. We have engineered a qubit-phonon coupling rate of g≈2π×14 MHzg\approx2\pi\times14~\text{MHz}, and achieved a dispersive interaction that exceeds the decoherence rates of both systems while the qubit and mechanics are highly nonresonant (Δ/g≳10\Delta/g\gtrsim10). Leveraging this strong coupling, we perform phonon number-resolved measurements of the mechanical resonator and investigate its dissipation and dephasing properties. Our results demonstrate the potential for fluxonium-based hybrid quantum systems, and a path for developing new quantum sensing and information processing schemes with phonons at frequencies below 700 MHz to significantly expand the toolbox of cQAD.Comment: 22 pages, 12 figure

    Thermography and thermoregulation of the face

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    BACKGROUND: Although clinical diagnosis of thermoregulation is gaining in importance there is no consistent evidence on the value of thermography of the facial region. In particular there are no reference values established with standardised methods. METHODS: Skin temperatures were measured in the facial area at 32 fixed measuring sites in 26 health subjects (7–72 years) with the aid of a contact thermograph (Eidatherm). A total of 6 measurements were performed separately for the two sides of the face at intervals of equal lengths (4 hours) over a period of 24 hours. Thermoregulation was triggered by application of a cold stimulus in the region of the ipsilateral ear lobe. RESULTS: Comparison of the sides revealed significant asymmetry of face temperature. The left side of the face showed a temperature that was on the average 0.1°C lower than on the right. No increase in temperature was found following application of the cold stimulus. However, a significant circadian rhythm with mean temperature differences of 0.7°C was observed. CONCLUSION: The results obtained should be seen as an initial basis for compiling an exact thermoprofile of the surface temperature of the facial region that takes into account the circadian rhythm, thus closing gaps in studies on physiological changes in the temperature of the skin of the face

    Immersion education outcomes and the Gaelic community:Identities and language ideologies among Gaelic-medium educated adults in Scotland

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    Scholars have consistently theorised that language ideologies can influence the ways in which bilingual speakers in minority language settings identify and engage with the linguistic varieties available to them. Research conducted by the author examined the interplay of language use and ideologies among a purposive sample of adults who started in Gaelic medium education during the first years of its availability. Crucially, the majority of participants’ Gaelic use today is limited, although notable exceptions were found among individuals who were substantially socialised in the language at home during childhood, and a small number of new speakers. In this paper, I draw attention to some of the language ideologies that interviewees conveyed when describing their cultural identifications with Gaelic. I argue that the ideologies that informants express seem to militate against their more frequent use of the language and their association with the wider Gaelic community. In particular, I discuss interviewees’ negative perceptions of the traditionally defined, ethnolinguistic identity category ‘Gael(s)’ in their expression of language ideologies and identities, and the implications of this finding for other contexts of minority language revitalisation
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