11,114 research outputs found

    Radiation/convection coupling in rocket motor and plume analysis

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    A method for describing radiation/convection coupling to a flow field analysis was developed for rocket motors and plumes. The three commonly used propellant systems (H2/O2, RP-1/O2, and solid propellants) radiate primarily as: molecular emitters, non-scattering small particles (soot), and scattering larger particles (Al2O3), respectively. For the required solution, the divergence of the radiation heat flux was included in the energy equation, and the local, volume averaged intensity was determined by a solution to the radiative transfer equation. A rigorous solution to this problem is intractable, therefore, solution methods which use the ordinary and improved differential approximation were developed. This radiation model was being incorporated into the FDNS code, a Navier-Stokes flowfield solver for multiphase, turbulent combusting flows

    Distributed storage manager system for synchronized and scalable AV services across networks

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    This article has been made available through the Brunel Open Access Publishing Fund - Copyright @ 2011 Hindawi Publishing CorporationThis paper provides an innovative solution, namely, the distributed storage manager that opens a new path for highly interactive and personalized services. The distributed storage manager provides an enhancement to the MHP storage management functionality acting as a value added middleware distributed across the network. The distributed storage manager system provides multiple protocol support for initializing and downloading both streamed and file-based content and provides optimum control mechanisms to organize the storing and retrieval of content that are remained accessible to other multiple heterogeneous devices

    Particle phase function measurements by a new Fiber Array Nephelometer: FAN 1

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    A fiber array polar nephelometer of advanced design, the FAN I is capable of in-situ phase function measurements of scattered light from man-made or natural atmospheric particles. The scattered light is measured at 100 different angles throughout 360 degrees, thus providing a potential measurement of the asymmetry of irregularly shaped particles. Phase functions can be measured at 10 to 100 Hz rates and the range of measurable single particle sizes is from 5 micron m to as large as 8mm. For particles smaller than 5 micro m the ensemble average can be measured. The FAN I is microprocessor controlled and the data may be stored on floppy disk or printed out in tabular and/or graphical form. The optical head may be separated from the computer system for operation in field or adverse conditions. Examples of laboratory measured scattering phase functions obtained with the FAN I for spherical particles is given to illustrate its measurement capabilities

    Crystallization of random trigonometric polynomials

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    We give a precise measure of the rate at which repeated differentiation of a random trigonometric polynomial causes the roots of the function to approach equal spacing. This can be viewed as a toy model of crystallization in one dimension. In particular we determine the asymptotics of the distribution of the roots around the crystalline configuration and find that the distribution is not Gaussian.Comment: 10 pages, 3 figure

    Effects of systematic errors on the mixing ratios of trace gases obtained from occulation spectra

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    The influence of systematic errors in the parameters of the models describing the geometry and the atmosphere on the profiles of trace gases retrieved from simulated solar occultation spectra, collected at satellite altitudes, is investigated. Because of smearing effects and other uncertainties, it may be preferable to calibrate the spectra internally by measuring absorption lines of an atmospheric gas such as CO2 whose vertical distribution is assumed rather than to relay on externally supplied information

    Market impact and trading profile of large trading orders in stock markets

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    We empirically study the market impact of trading orders. We are specifically interested in large trading orders that are executed incrementally, which we call hidden orders. These are reconstructed based on information about market member codes using data from the Spanish Stock Market and the London Stock Exchange. We find that market impact is strongly concave, approximately increasing as the square root of order size. Furthermore, as a given order is executed, the impact grows in time according to a power-law; after the order is finished, it reverts to a level of about 0.5-0.7 of its value at its peak. We observe that hidden orders are executed at a rate that more or less matches trading in the overall market, except for small deviations at the beginning and end of the order.Comment: 9 pages, 7 figure

    Reviews

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    Review of The Industrial Relations Amending Legislation of 1976, Industrial Conflict: A Study of Three New Zealand Industries, A Seventh Man, Economists at Bay - Why the Experts Will Never Solve Your Problem

    Returning children home from care: What can be learned from local authority data?

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    International Human Rights and child rights conventions as well as U.K. wide legislation and guidance require that children in care should be returned home to one or both parents wherever possible. Reunification with parents is the most common route out of care, but rates of re‐entry are often higher than for other exit routes. This study used 8 years of administrative data (on 2,208 care entrants), collected by one large English local authority, to examine how many children were returned home and to explore factors associated with stable reunification (not re‐entering care for at least 2 years). One‐third of children (36%) had been reunified, with adolescent entrants being the most likely age group to return home. Three quarters (75%) of reunified children had a stable reunification. In a fully adjusted regression model, age at entry, being on a care order prior to return home, staying longer in care, being of minority ethnicity, and having fewer placements in care were all significant in predicting chances of stable reunification. The results underline the importance of properly resourcing reunification services. The methods demonstrate the value to local authorities of analysing their own data longitudinally to understand the care pathways for children they look after

    When the Window Cracks: Transparency and the Fractured Self in Depersonalisation

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    There has recently been a resurgence of philosophical and scientific interest in the foundations of self-consciousness, with particular focus on its altered, anomalous forms. This paper looks at the altered forms of self-awareness in Depersonalization Disorder (DPD), a condition in which people feel detached from their self, their body and the world (Derealisation). Building upon the phenomenological distinction between reflective and pre-reflective self-consciousness, we argue that DPD may alter the transparency of basic embodied forms of pre-reflective self-consciousness, as well as the capacity to flexibly modulate and switch between the reflective and pre-reflective facets of self-awareness. Empirical evidence will be invoked in support of the idea that impaired processing of bodily signals is characteristic of the condition. We provide first-hand subjective reports describing the experience of self-detachment or fracture between an observing and an observed self. This split is compared with similar self-detachment phenomena reported in certain Buddhist-derived meditative practices. We suggest that these alterations and changes may reveal the underlying and tacit transparency that characterises the embodied and basic pre-reflective forms of self-consciousness, in the same way that a crack in a transparent glass may indicate the presence of an unnoticed window
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