30,980 research outputs found

    The Haunting of L.S. Lowry: Class, Mass Spectatorship and the Image at The Lowry, Salford, UK

    Get PDF
    In a series of momentary encounters with the surface details of The Lowry Centre, a cultural venue located in Salford, Greater Manchester, UK, this article considers the fate of the image evoked by the centre’s production and staging of cultural experience. Benjamin’s notion of ‘aura’ as inimical to transformations of art and cultural spectatorship is explored, alongside its fatal incarnation in Baudrillard’s concept of ‘simulation’. L.S. Lowry, I argue, occupies the space as a medium: both as a central figure of transmission of the centre’s narrative of inclusivity through cultural regeneration, and as one who communes with phantoms: remainders of the working-class life and culture that once occupied this locale. Through an exploration of various installations there in his name, Lowry is configured as a ‘destructive character’, who, by making possible an alternative route through its spaces, refuses to allow The Lowry Centre to insulate itself from its locale and the debt it owes to its past

    Actuator participation in a bending mode identification system

    Get PDF
    A hydraulic actuator designed for a thrust vector control system used as a shaker for a vehicle to determine the bending mode frequencies is described. The actuator is used as the prime mover and the frequency sensor for the flexible vehicle in a test tower. Advantages in using the actuator piston position with respect to a commanded position to obtain the bending mode frequencies are shown

    Numerical generation of two-dimensional orthogonal curvilinear coordinates in an Euclidean space

    Get PDF
    A noniterative method for the numerical generation of orthogonal curvilinear coordinates for plane annular regions between two arbitrary smooth closed curves was developed. The basic generating equation is the Gaussian equation for an Euclidean space which is solved analytically. The method is applied in many cases and these test results demonstrate that the proposed method can be readily applied to a wide variety of problems. The method can also be used for simply connected regions only by obtaining the solution of the linear equation under the changed boundary conditions

    Numerical solution of the Navier-Stokes equations for blunt nosed bodies in supersonic flows

    Get PDF
    A time dependent, two dimensional Navier-Stokes code employing the method of body fitted coordinate technique was developed for supersonic flows past blunt bodies of arbitrary shapes. The bow shock ahead of the body is obtained as part of the solution, viz., by shock capturing. A first attempt at mesh refinement in the shock region was made by using the forcing function in the coordinate generating equations as a linear function of the density gradients. The technique displaces a few lines from the neighboring region into the shock region. Numerical calculations for Mach numbers 2 and 4.6 and Reynolds numbers from 320 to 10,000 were performed for a circular cylinder with and without a fairing. Results of Mach number 4.6 and Reynolds number 10,000 for an isothermal wall temperature of 556 K are presented in detail

    BVRI Observations of the Optical Afterglow of GRB 990510

    Get PDF
    We present BVRIBVRI observations of the optical counterpart to the Gamma-Ray Burst (GRB) 990510 obtained with the Las Campanas 1.0-m telescope between 15 and 48 hours after the burst. The temporal analysis of the data indicates steepening decay, independent of wavelength, approaching asymptotically t−0.76±0.01t^{-0.76\pm 0.01} at early times (t≪1day)t\ll 1 day) and t−2.40±0.02t^{-2.40\pm 0.02} at late times, with the break time at t0=1.57±0.03dayst_0=1.57\pm 0.03 days. GRB 990510 is the most rapidly fading of the well-documented GRB afterglows. It is also the first observed example of broad-band break for a GRB optical counterpart. The optical spectral energy distribution, corrected for significant Galactic reddening, is well fitted by a single power-law with ν−0.61±0.12\nu^{-0.61\pm 0.12}. However, when the BB-band point is dropped from the fit, the power-law becomes ν−0.46±0.08\nu^{-0.46\pm 0.08}, indicating a possible deviation from the power-law in the spectrum, either intrinsic or due to additional extinction near the source or from an intervening galaxy at z=1.62z=1.62. Broad-band break behavior broadly similar to that observed in GRB 990510 has been predicted in some jet models of GRB afterglows, thus supporting the idea that the GRB energy is beamed, at least in some cases.Comment: submitted to the ApJ Letters, 13 pages, 5 tables, 3 figures; additional data available at ftp://cfa-ftp.harvard.edu/pub/kstanek/GRB990510/ and through WWW at http://cfa-www.harvard.edu/cfa/oir/Research/GRB

    EFFECT OF POLYMER DESIGN AND COATING FORMULATION ON THE WATER UPTAKE AND SENSITIVITY OF ACRYLIC WATER-BORNE FILMS

    Get PDF
    Water-borne latex coatings represent a safer, more user-friendly, and environmentally responsible alternative to solvent-borne coatings, and are growing in popularity each year. However, these coatings often exhibit unfavorable performance when exposed to water for extended periods of time. This prolonged exposure often results in water uptake, which may give rise to other detrimental effects such as a decrease in modulus, blushing or water-whitening, reduced serviceable life, and softening of the film. In this study, various polymer composition latex design spaces are studied to develop an understanding of how water uptake can be modulated and minimized using common synthetic approaches. Factors including monomer selection, particle size, polymer molecular weight, crosslinking density, surfactant choice and particle stabilization, processing variables and Tg are considered. In addition, some formulation modifications including PVC, film thickness, and choice of coalescent package are explored to gain a more comprehensive understanding of final product performance. In quantifying the total water uptake of the films, gravimetric analysis tends to be the preferred method employed in the coatings industry. However, other analytical approaches can be used to better understand the effect that water has on the properties of the film. These methods may include differential scanning calorimetry, electrochemical impedance spectroscopy, immersion testing using dynamic mechanical analysis, and others. In the work, it has been shown that interparticle crosslinking, surfactant, and monomer selection can have an extreme influence on the water uptake of free films. Film samples exhibit a range of water uptake values from nearly 200% to less than 5% over a one-week soak in deionized water. It is thought that the surfactant may provide hydrophilic channels that allow water to v penetrate the film and form heterogeneous domains within the coating. These domains then grow and scatter light, leading to water-whitening and an increase in mass when compared to the dry film. Utilizing monomers with differing relative solubilities in water, such as methyl methacrylate and styrene, further allow control of this effect. Interparticle crosslinking via keto-hydrazide crosslinking, which is achieved during the film formation process, can also prevent the formation and growth of these large water domains, thus resulting in better performing films
    • …
    corecore