588 research outputs found

    Improved high pressure turbine shroud

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    A new high pressure turbine shroud material has been developed from the consolidation of prealloyed powders of Ni, Cr, Al and Y. The new material, a filler for cast turbine shroud body segments, is called Genaseal. The development followed the identification of oxidation resistance as the primary cause of prior shroud deterioration, since conversion to oxides reduces erosion resistance and increases spalling under thermal cycled engine conditions. The NICrAlY composition was selected in preference to NIAL and FeCRALY alloys, and was formulated to a prescribed density range that offers suitable erosion resistance, thermal conductivity and elastic modulus for improved behavior as a shroud

    Multivariate phase space reconstruction by nearest neighbor embedding with different time delays

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    A recently proposed nearest neighbor based selection of time delays for phase space reconstruction is extended to multivariate time series, with an iterative selection of variables and time delays. A case study of numerically generated solutions of the x- and z coordinates of the Lorenz system, and an application to heart rate and respiration data, are used for illustration.Comment: 4 pages, 3 figure

    Measuring Information Transfer

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    An information theoretic measure is derived that quantifies the statistical coherence between systems evolving in time. The standard time delayed mutual information fails to distinguish information that is actually exchanged from shared information due to common history and input signals. In our new approach, these influences are excluded by appropriate conditioning of transition probabilities. The resulting transfer entropy is able to distinguish driving and responding elements and to detect asymmetry in the coupling of subsystems.Comment: 4 pages, 4 Figures, Revte

    Zarin v. Commissioner: The Continuing Validity of Case Law Exceptions to Discharge of Indebtedness Income

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    This Casenote examines Zarin v. Commissioner, decided by the United States Court of Appeal for the Third Circuit in 1990. This case considered exceptions to the general rule that income from the discharge of indebtedness is included as gross income under the Internal Revenue Code. The court found these exceptions valid. This Casenote argues that the court\u27s reasoning in Zarin v. Commissioner assures that its decision will have implications well beyond the facts of the case. The author also suggests that these exceptions are both reinforced and expanded by this case. He concludes that the result of this case is a more flexible approach to disputed liability issues, which should engender more rational decisions in the tax law area

    Webteaching: sequencing of subject matter in relation to prior knowledge of pupils

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    Two experiments are discussed in which the sequencing procedure of webteaching is compared with a linear sequence for the presentation of text material.\ud \ud In the first experiment variations in the level of prior knowledge of pupils were studied for their influence on the sequencing mode of text presentation. Prior knowledge greatly reduced the effect of the size of sequencing procedures.\ud \ud In the second experiment pupils with a low level of prior knowledge studied a text, following either a websequence or a linear sequence. Webteaching was superior to linear teaching on a number of dependent variables. It is concluded that webteaching is an effective sequencing procedure in those cases where substantial new learning is required

    Barriers and facilitators for health professionals referring Aboriginal and Torres Strait Islander tobacco smokers to the Quitline

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    Objective: To examine the barriers and facilitators among health professionals to providing referrals to Quitline for Aboriginal and Torres Strait Islander clients who smoke. Methods: A brief online survey, based on the Theoretical Domains Framework, was completed by 34 health professionals who work with Aboriginal and Torres Strait Islander people in South Australia and the Northern Territory. Results: Respondents who frequently made referrals had higher domain scores than less frequent referrers for ‘Skills and knowledge’ (M=4.44 SD=0.39 vs. M=4.09 SD=0.47, p<0.05) and ‘beliefs about capabilities’ (M=4.33 SD=0.44 vs. M=3.88 SD=0.42, p<0.01). Barriers to providing referrals to Quitline were lack of client access to a phone, cost of a phone call, preference for face-to-face interventions, and low client motivation to quit. Conclusions: Health professionals working with Aboriginal and Torres Strait Islander clients should be supported to build their skills and confidence to provide referrals to Quitline and other brief cessation interventions. Building capacity for face-to-face support locally would be beneficial where phone support is not preferable. Implications for public health: Engaging with health professionals who work with Aboriginal and Torres Strait Islander people to increase referrals to Quitline is strategic as it builds on their existing capacity to provide cessation support.Kimberley Martin, Joanne Dono, Nathan Rigney, Joanne Rayner, Alana Sparrow, Caroline Miller, Andrea Mckivett, Kerin O'Dea, David Roder, Jacqueline Bowde

    A new direction for water management? Indigenous nation building as a strategy for river health

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    © 2017 by the author(s). Indigenous involvement in Australian water management is conventionally driven by a top-down approach by nonIndigenous government agencies, that asks “how do we engage Indigenous people?” and has culminated in the ineffective “consult” and “service delivery” processes evident in mainstream water management planning. This is a hopeful paper that identifies the critical importance of a “nation-based” approach for effective Indigenous engagement in water planning and policy through the work undertaken by the Ngarrindjeri Regional Authority (NRA) in the Murray Futures program. The NRA is an Indigenous government in the “settled-south” of Australia. Over past decades, the NRA has developed a range of political technologies that act as tools for redeveloping Ngarrindjeri Nationhood after colonial disempowerment and dispossession. These tools enable better collaboration with nonIndigenous governments, especially in natural resource management policy and practice. In turn, this has better enabled the NRA to exercise a decision-making and planning authority over the lands and waters in its jurisdiction, therefore, more effectively exercising its ongoing duty of care as Country. This paper presents a case study of the Sugar Shack Complex Management Plan, codeveloped by the NRA and the South Australian Government in 2015, to demonstrate the benefits that accrue when Indigenous nations are resourced as authorities responsible for reframing water management and planning approaches to facilitate the equitable collaboration of Indigenous and nonIndigenous worldviews. As a marker of the success of this strategy, the Ngarrindjeri Yarluwar-Ruwe Program, in partnership with the South Australian government, recently won the Australian Riverprize 2015 for delivering excellence in Australian river management

    Test your surrogate data before you test for nonlinearity

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    The schemes for the generation of surrogate data in order to test the null hypothesis of linear stochastic process undergoing nonlinear static transform are investigated as to their consistency in representing the null hypothesis. In particular, we pinpoint some important caveats of the prominent algorithm of amplitude adjusted Fourier transform surrogates (AAFT) and compare it to the iterated AAFT (IAAFT), which is more consistent in representing the null hypothesis. It turns out that in many applications with real data the inferences of nonlinearity after marginal rejection of the null hypothesis were premature and have to be re-investigated taken into account the inaccuracies in the AAFT algorithm, mainly concerning the mismatching of the linear correlations. In order to deal with such inaccuracies we propose the use of linear together with nonlinear polynomials as discriminating statistics. The application of this setup to some well-known real data sets cautions against the use of the AAFT algorithm.Comment: 14 pages, 15 figures, submitted to Physical Review

    Acting as Country

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    Glossary with a focus on concepts of race, indigeneity and new ideas in radical ecology

    Statistical Theory of Spin Relaxation and Diffusion in Solids

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    A comprehensive theoretical description is given for the spin relaxation and diffusion in solids. The formulation is made in a general statistical-mechanical way. The method of the nonequilibrium statistical operator (NSO) developed by D. N. Zubarev is employed to analyze a relaxation dynamics of a spin subsystem. Perturbation of this subsystem in solids may produce a nonequilibrium state which is then relaxed to an equilibrium state due to the interaction between the particles or with a thermal bath (lattice). The generalized kinetic equations were derived previously for a system weakly coupled to a thermal bath to elucidate the nature of transport and relaxation processes. In this paper, these results are used to describe the relaxation and diffusion of nuclear spins in solids. The aim is to formulate a successive and coherent microscopic description of the nuclear magnetic relaxation and diffusion in solids. The nuclear spin-lattice relaxation is considered and the Gorter relation is derived. As an example, a theory of spin diffusion of the nuclear magnetic moment in dilute alloys (like Cu-Mn) is developed. It is shown that due to the dipolar interaction between host nuclear spins and impurity spins, a nonuniform distribution in the host nuclear spin system will occur and consequently the macroscopic relaxation time will be strongly determined by the spin diffusion. The explicit expressions for the relaxation time in certain physically relevant cases are given.Comment: 41 pages, 119 Refs. Corrected typos, added reference
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