44,253 research outputs found
Disk Evolution in Young Binaries: from Observations to Theory
The formation of a binary system surrounded by disks is the most common
outcome of stellar formation. Hence studying and understanding the formation
and the evolution of binary systems and associated disks is a cornerstone of
star formation science. Moreover, since the components within binary systems
are coeval and the sizes of their disks are fixed by the tidal truncation of
their companion, binary systems provide an ideal "laboratory" in which to study
disk evolution under well defined boundary conditions.
In this paper, we review observations of several inner disk diagnostics in
multiple systems, including hydrogen emission lines (indicative of ongoing
accretion), and color excesses (evidence of warm inner disks), and
polarization (indicative of the relative orientations of the disks around each
component). We examine to what degree these properties are correlated within
binary systems and how this degree of correlation depends on parameters such as
separation and binary mass ratio. These findings will be interpreted both in
terms of models that treat each disk as an isolated reservoir and those in
which the disks are subject to re-supply from some form of circumbinary
reservoir, the observational evidence for which we will also critically review.
The planet forming potential of multiple star systems is discussed in terms of
the relative lifetimes of disks around single stars, binary primaries and
binary secondaries. Finally, we summarize several potentially revealing
observational problems and future projects that could provide further insight
into disk evolution in the coming decadeComment: 16 pages, 7 figures, chapter in Protostars and Planets
Building systems and indoor environment : simulation for design decision support
This paper outlines the state-of-the-art in integrated building simulation for design support. The ESP-r system is used as an example where integrated simulation is a core philosophy behind the development. The paper finishes with indicating a number of barriers, which hinder routine application of simulation for building design
Integrated simulation for (sustainable) building design : state-of-the-art illustration
Many buildings are still constructed or remodelled without consideration of energy conserving strategies or other sustainability aspects. To provide substantial improvements in energy consumption and comfort levels, there is a need to treat buildings as complete optimised entities not as the sum of a number of separately optimised components
It's all action, it's all learning: Action learning in SMEs
Purpose - The purpose of this paper is to argue that action learning (AL) may provide a means of successfully developing small to medium-sized enterprises (SMEs). Design/methodology/approach - The literature around SME learning suggests a number of processes are important for SME learning which similarity, it is argued, are encompassed in AL. AL may therefore offer a means of developing SME. This argument is then supported through the results of a longitudinal qualitative evaluation study conducted in the north-west of England, which involved the use of AL in 100 SMEs. Findings - The paper finds that the discursive and critical reflection aspects of the set environment appeared to be of great utility and importance to the SMEs. Sets also had an optimum level of which helped them find "common ground". Once common ground was established set members often continued to network and form alliances outside of the set environment. SME owner-managers could discuss both personal and business. Finally, AL offered the opportunity to take time out of the business and "disengage" with the operational allowing them to become more strategic. Practical implications - In this paper both the literature review and the results of the evaluation suggest AL may offer a means of engaging SMEs in training, which is relevant and useful to them. AL offers a way for policy makers and support agencies to get involved with SME management development while retaining context and naturalistic conditions. Originality/value - This paper attempts to move beyond other articles which assess SME response to government initiatives, through examining the literature around SME learning and constructing a rationale which proposes that AL encompasses many of the learning processes suggested in the literature as effective for SME development. © Emerald Group Publishing Limited
The Deterrent Effects of National Anti-Cartel Laws: Evidence from the International Vitamins Cartel
This paper estimates the effect on international trade flows during the 1990s of the formation of the vitamins cartel. After this cartel began operating, exports from countries where the cartel conspirators' headquarters were located to those nations in Asia, Western Europe, and Latin America that did not have active cartel enforcement regimes tended to rise in value more than in those nations that had such regimes. As industry studies suggest that the demand for vitamins is price inelastic, this finding is supportive of the hypothesis that the vitamins cartel raised prices further in nations without active cartel enforcement regimes. These findings also have implications for the cost-benefit analyses of anti-cartel laws. In nine economies in Western Europe and Latin America, where recent estimates of government outlays on competition policy enforcement were found, these expenditures were compared to the additional overcharges on vitamins imports that would have resulted if each of these nations did not have an active cartel enforcement regime. In seven of the nine economies, the reduction in overcharges on this one international cartel alone exceeded a quarter of their government's spending on the entire competition policy enforcement regime. These findings have a direct bearing on the debate, currently taking place at the World Trade Organization, on the merits of multilateral disciplines that would require all WTO members to enact and enforce provisions against hard core cartels.
Research and Teacher Education: The BERA-RSA inquiry. Policy and Practice within the United Kingdom.
Across the four jurisdictions of the United Kingdom (England, Northern Ireland, Scotland and Wales) initial teacher education (ITE) is under active development, with its content, location, control and quality often the focuses of sustained debate. Statutory and professional requirements for the sector inevitably reflect differing assumptions about teaching, teacher knowledge and governance. In exploring ITE across the four jurisdictions, this paper reviews policies and practices through two major focuses: first, the relationships between the declared teacher standards (competencies/competences) and research-informed teacher education provision; second, the âturn or (re)turn to the practicalâ in teacher education, including policy declarations, changes in practices, and emphases and effects of the discourse(s) of relevance
Bond behavior of fiber reinforced polymer bars under direct pullout conditions
This paper examines the behavior of Eurocrete fiber-reinforced polymer (FRP) bars (glass, carbon, aramid, and hybrid) in concrete under direct pullout conditions. More than 130 cube specimens were tested in direct pullout where no splitting was allowed to develop. In normal concrete, the mode of bond failure of FRP bars was found to differ substantially from that of deformed steel bars because of damage to the resin rich surface of the bar when pullout takes place. Bond strengths developed by carbon fiber-reinforced polymer and glass fiber-reinforced polymer bars appear to be very similar and just below what is expected from deformed steel bars under similar experimental conditions. The load slip curves highlight some of the fundamental differences between steel and FRP materials. This paper reports in detail on the influence of various parameters that affect bond strength and development such as the embedment length, type, shape, surface characteristics, and diameter of the bar as well as concrete strength. The testing arrangement is also shown to influence bond strength because of the âwedging effectâ of the bars
Localization of Metal-Induced Gap States at the Metal-Insulator Interface:Origin of Flux Noise in SQUIDs and Superconducting Qubits
The origin of magnetic flux noise in Superconducting Quantum Interference
Devices with a power spectrum scaling as ( is frequency) has been a
puzzle for over 20 years. This noise limits the decoherence time of
superconducting qubits. A consensus has emerged that the noise arises from
fluctuating spins of localized electrons with an areal density of
m. We show that, in the presence of potential disorder
at the metal-insulator interface, some of the metal-induced gap states become
localized and produce local moments. A modest level of disorder yields the
observed areal density
Catalytic constructive deoxygenation of lignin-derived phenols: new C-C bond formation processes from imidazole-sulfonates and ether cleavage reactions
Funding: UK Engineering and Physical Sciences Research Council (EPSRC)As part of a programme aimed at exploiting lignin as a chemical feedstock for less oxygenated fine chemicals, several catalytic C-C bond forming reactions utilising guaiacol imidazole sulfonate are demonstrated. These include the cross-coupling of a Grignard, a non-toxic cyanide source, a benzoxazole, and nitromethane. A modified Meyers reaction is used to accomplish a second constructive deoxygenation on a benzoxazole functionalised anisole.Publisher PDFPeer reviewe
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