22,329 research outputs found

    Simulation of colloidal chain movements under a magnetic field

    Full text link
    Short colloidal chains are simulated by the slithering-snake-algorithm on a simple cubic lattice. The dipole character of the colloidal particles leads to a long range dipole-dipole interaction. The solvent is simulated by the nearest neighbor Ising model. The aligning of the dipoles under a magnetic field gives rise to the chains to align on their part with the field direction.Comment: 3 pages for Int. J. Mod. Phys. C 16, issue

    String universality in ten dimensions

    Full text link
    We show that the N=1{\cal N}=1 supergravity theories in ten dimensions with gauge groups U(1)496U(1)^{496} and E8Ă—U(1)248E_8 \times U(1)^{248} are not consistent quantum theories. Cancellation of anomalies cannot be made compatible with supersymmetry and abelian gauge invariance. Thus, in ten dimensions all supersymmetric theories of gravity without known inconsistencies are realized in string theory.Comment: 7 pages, 1 figure, LaTeX. v2: typos corrected on version appearing in PR

    Principal-Agent Relationships in Agricultural Cooperatives: An Empirical Analysis from Rural Alberta

    Get PDF
    Cooperatives throughout North America are consolidating at an increasing rate and for a variety of reasons. While many cooperatives merge with others or are acquired to achieve greater economies of scale, several fail due to changes in the external economy, which make them redundant. Often, such redundancy is reflected in a heightened sense of member dissatisfaction. Many argue that such dissatisfaction is likely to arise in cooperatives as a result of principal-agent problems. In order to determine whether or not cooperative managers maintain the same goals as their owners, this study uses data from a member-survey to compare Alberta cooperative members' objectives with those they believe to be held by their cooperatives' managers. An econometric model of the difference between members' expectations and perceptions shows how various socioeconomic variables affect the extent to which these objectives are aligned. The results of this analysis can help cooperative boards design managerial incentive programs to better align their goals with those of the cooperative membership.Agribusiness,

    Meeting of the MINDS: an information retrieval research agenda

    Get PDF
    Since its inception in the late 1950s, the field of Information Retrieval (IR) has developed tools that help people find, organize, and analyze information. The key early influences on the field are well-known. Among them are H. P. Luhn's pioneering work, the development of the vector space retrieval model by Salton and his students, Cleverdon's development of the Cranfield experimental methodology, Spärck Jones' development of idf, and a series of probabilistic retrieval models by Robertson and Croft. Until the development of the WorldWideWeb (Web), IR was of greatest interest to professional information analysts such as librarians, intelligence analysts, the legal community, and the pharmaceutical industry

    Smoke signals: An investigation of anti-smoking communication within marginalised communities within the health system. An outline research proposal

    Full text link
    Purpose: This paper outlines a case for investigation of why current anti-smoking advertising and promotional messaging is not having positive effects amongst smokers within the health system who are marginalised and experience mental illness. Design/methodology/approach: It is proposed that a case study approach be adopted using qualitative research amongst respondents from within the Brisbane Health system, using a semi-structured questionnaire with appropriate communication stimuli. Originality/value: Previous research demonstrates anti-smoking messaging is having effects on smoking cessation amongst the general population. However, smokers who are marginalised within the health system appear not to be responding to health warnings and anti-smoking advertising messaging. No research is available on why current anti-smoking messaging is having minimal resonance and effects amongst this group. This qualitative study will offer opportunities for leadership and application of best practice communication in helping people make a truly informed choice about tobacco

    The Influence of Swirl Brakes on the Rotordynamic Forces Generated by Discharge-to-Suction Leakage Flows in Centrifugal Pumps

    Get PDF
    Increasing interest has been give to swirl brakes as a means of reducing destabilizing rotordynamic forces due to leakage flows in new high speed rocket turbopumps. Although swirl brakes have been used successfully in practice (such as with the Space Shuttle HPOTP), no experimental test until now have been performed to demonstrate their beneficial effect over a range of leakage flow rates. The present study investigates the effect of swirl brakes on rotordynamic forces generated by discharge-to-suction leakage flows in the annulus of shrouded centrifugal pumps over a range of subsynchronous whirl ratios and various leakage flow rates. In addition, the effectiveness of swirl brakes in the presence of leakage inlet (pump discharge) swirl is also demonstrated. The experimental data demonstrates that with the addition of swirl brakes a significant reduction in the destabilizing tangential force for lower flow rates is achieved. At higher flow rates, the brakes are detrimental. In the presence of leakage inlet swirl, brakes were effective over all leakage flow rates tested in reducing the range of whirl frequency ratio for which the tangential force is destabilizing

    IVOA Recommendation: SAMP - Simple Application Messaging Protocol Version 1.3

    Full text link
    SAMP is a messaging protocol that enables astronomy software tools to interoperate and communicate. IVOA members have recognised that building a monolithic tool that attempts to fulfil all the requirements of all users is impractical, and it is a better use of our limited resources to enable individual tools to work together better. One element of this is defining common file formats for the exchange of data between different applications. Another important component is a messaging system that enables the applications to share data and take advantage of each other's functionality. SAMP builds on the success of a prior messaging protocol, PLASTIC, which has been in use since 2006 in over a dozen astronomy applications and has proven popular with users and developers. It is also intended to form a framework for more general messaging requirements

    An emerging theory of apology

    Get PDF
    There is no consensus in the psychological literature regarding the operational definition of an apology, nor is there a comprehensive theory of apology. The object of this study was to use a hermeneutic phenomenological approach and grounded theory methodology to develop a theory of apology based on lay people\u27s interpretation of apologetic responses. Data were methodically gathered by interviewing 23 people who had been wronged by an intimate partner. The analysis of the data suggests that there is not a single discrete definition of an apology, but that it is more appropriate to conceptualise apology as a process that consists of one or more of three components: affect, affirmation, and action. Each of these components has two categories; one that reflects a self-focus on the part of the wrongdoer, and the other a self–other focus. What will be accepted as a good enough apology appears to depend on the severity of the consequences of the wrong, the level of responsibility attributed to the wrongdoer, and the perceived wrongfulness of the behaviour
    • …
    corecore