22,347 research outputs found

    The inverse problem for pulsating neutron stars: A ``fingerprint analysis'' for the supranuclear equation of state

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    We study the problem of detecting, and infering astrophysical information from, gravitational waves from a pulsating neutron star. We show that the fluid f and p-modes, as well as the gravitational-wave w-modes may be detectable from sources in our own galaxy, and investigate how accurately the frequencies and damping rates of these modes can be infered from a noisy gravitational-wave data stream. Based on the conclusions of this discussion we propose a strategy for revealing the supranuclear equation of state using the neutron star fingerprints: the observed frequencies of an f and a p-mode. We also discuss how well the source can be located in the sky using observations with several detectors.Comment: 9 pages, 3 figure

    Inclusion of mussel meal in diets to growing/finishing pigs

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    This study showed that inclusion of mussel meal in diets to growing/finishing pigs yielded growth rate similar to those obtained with a conventional diet, whereas feed conversion ratio was higher. This implies that mussel meal is a potential alternative protein source that can replace fish and soybean meal in organic diets. By using mussels it would be possible to compose diets with 100% organic feed ingredients. However, mussel meal is currently expensive to produce and in addition more research regarding optimal inclusion level and possible off-flavor of the meat is needed

    Evolution equations for the perturbations of slowly rotating relativistic stars

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    We present a new derivation of the equations governing the oscillations of slowly rotating relativistic stars. Previous investigations have been mostly carried out in the Regge-Wheeler gauge. However, in this gauge the process of linearizing the Einstein field equations leads to perturbation equations which as such cannot be used to perform numerical time evolutions. It is only through the tedious process of combining and rearranging the perturbation variables in a clever way that the system can be cast into a set of hyperbolic first order equations, which is then well suited for the numerical integration. The equations remain quite lengthy, and we therefore rederive the perturbation equations in a different gauge, which has been first proposed by Battiston et al. (1970). Using the ADM formalism, one is immediately lead to a first order hyperbolic evolution system, which is remarkably simple and can be numerically integrated without many further manipulations. Moreover, the symmetry between the polar and the axial equations becomes directly apparent.Comment: 13 pages, no figures, MSRAS typesetting, cleaning of the inadvertently disfigured equation

    Lean-inspired development work in agriculture: Implications for the work environment

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    Farmers operate in a turbulent environment that includes international competition, weather conditions and animal behaviour, for example, and is difficult for them to control. However, economy and productivity always have a high priority. As a consequence, farms have started to implement lean-inspired work systems. At the same time, health and safety are of urgent concern in the sector. This article explores how famers apply lean-inspired work processes. It identifies work environment changes during and after a lean implementation, as well as possible developments in the work environment following implementation of the lean philosophy. Data were collected from three groups: lean, lean-light and development-inclined reference farms (in total 54 farms), using a questionnaire and interviews. The results indicate that a majority of the lean farms were applying several lean principles and tools, and the lean philosophy. The leanlight farms applied parts of the lean concept, while the reference farms applied some of the more general tools, used in lean and elsewhere, such as visualisation in various forms and to various extents. The results showed positive effects of lean on the psychosocial work environment, better work structure and improved information, communication and co-operation. The physical work environment was improved to some extent by lean, where advantages such as a more structured and practical work environment with less physical movements and locomotion could be noticed. The lean concept provided a more structured and systematic approach to dealing with work and production environmental issues, for managers as well as for employees

    TGF-β1 as a prognostic factor in the process of early osteoarthrosis in the rabbit knee

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    AbstractObjective To assess changes in knee joint fluid concentrations of transforming growth factor-β1 (TGF-β1) and proteoglycan (PG) fragments during the early course of post-traumatic osteoarthrosis (OA) after meniscectomy in the rabbit knee, and to ascertain whether the concentrations of these substances shortly after operation could be used as prognostic markers for the OA process.Design In 15 rabbits with medial meniscectomy in one knee and a sham operation in the other knee, synovial lavage fluid samples were taken repeatedly, before operation, every third week post-operatively until 12 weeks, thereafter every sixth week, and at death. Five rabbits each were killed at 13, 25 and 40 weeks. Synovial lavage fluid samples from five non-operated rabbits served as controls. At death, two histological scores were formed that characterized the highest (MAX) and the overall (ALL) degree of OA changes in each joint.Results TGF-β1 and PG fragment concentrations in synovial lavage fluid correlated highly (R=0.81, P< 0.001). Both OA scores were higher in meniscectomized than controls (P< 0.05). The synovial lavage fluid concentration of TGF-β1 at 3 weeks, but no other time point, correlated to the histological scores (ALL, R=0.58; MAX, R=0.52;P< 0.001).Conclusion Higher concentrations of TGF-β1 in synovial lavage fluid early after surgery seemed indicative for the later development of more severe OA changes in contrast to lower concentrations. The association between TGF-β1 and the changes found later in the cartilage was underlined by the high correlations between this substance and PG fragment concentrations in synovial lavage fluid at all time points

    Quark-Gluon-Plasma Formation at SPS Energies?

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    By colliding ultrarelativistic ions, one achieves presently energy densities close to the critical value, concerning the formation of a quark-gluon-plasma. This indicates the importance of fluctuations and the necessity to go beyond the investigation of average events. Therefore, we introduce a percolation approach to model the final stage (τ>1\tau > 1 fm/c) of ion-ion collisions, the initial stage being treated by well-established methods, based on strings and Pomerons. The percolation approach amounts to finding high density domains, and treating them as quark-matter droplets. In this way, we have a {\bf realistic, microscopic, and Monte--Carlo based model which allows for the formation of quark matter.} We find that even at SPS energies large quark-matter droplets are formed -- at a low rate though. In other words: large quark-matter droplets are formed due to geometrical fluctuation, but not in the average event.Comment: 7 Pages, HD-TVP-94-6 (1 uuencoded figure

    Search for charginos, neutralinos, and gravitinos at LEP

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    The hep-ex data base was decided not to be an appropriate place to make DELPHI notes public. Sorry for the inconvenience.Comment: the paper should not have been made publi

    Advanced ceramic coating development for industrial/utility gas turbine applications

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    The effects of ceramic coatings on the lifetimes of metal turbine components and on the performance of a utility turbine, as well as of the turbine operational cycle on the ceramic coatings were determined. When operating the turbine under conditions of constant cooling flow, the first row blades run 55K cooler, and as a result, have 10 times the creep rupture life, 10 times the low cycle fatigue life and twice the corrosion life with only slight decreases in both specific power and efficiency. When operating the turbine at constant metal temperature and reduced cooling flow, both specific power and efficiency increases, with no change in component lifetime. The most severe thermal transient of the turbine causes the coating bond stresses to approach 60% of the bond strengths. Ceramic coating failures was studied. Analytic models based on fracture mechanics theories, combined with measured properties quantitatively assessed both single and multiple thermal cycle failures which allowed the prediction of coating lifetime. Qualitative models for corrosion failures are also presented

    Phase Relations in the Li2O-V2O3-V2O5 System at 700 C: Correlations with Magnetic Defect Concentration in Heavy Fermion LiV2O4

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    The phase relations in the Li2O-V2O3-V2O5 ternary system at 700 C for compositions in equilibrium with LiV2O4 are reported. This study clarified the synthesis conditions under which low and high magnetic defect concentrations can be obtained within the spinel structure of LiV2O4. We confirmed that the LiV2O4 phase can be obtained containing low (0.006 mol%) to high (0.83 mol%) magnetic defect concentrations n{defect} and with consistently high magnetic defect spin S values between 3 and 6.5. The high n{defect} values were obtained in the LiV2O4 phase in equilibrium with V2O3, Li3VO4, or LiVO2 and the low values in the LiV2O4 phase in equilibrium with V3O5. A model is suggested to explain this correlation.Comment: 6 pages, 7 figures; Phys. Rev. B (accepted
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