1,565 research outputs found

    Suggestion of a Tower from R.J. Hamilton, Architect

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    A correspondence in which R.J. Hamilton reaches out the university\u27s Lewis Memorial Building Committee to suggest a possible tower memorial rather than chimes. His letter says that he included several photos of the Memorial Lawns Cemetery Tower which he designed. He offers his architect skills for when the university is hiring.https://scholars.fhsu.edu/buildings/1054/thumbnail.jp

    Declining grouper spawning aggregations in Western Province, Solomon Islands, signal the need for a modified management approach

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    Globally, groupers (Epinephelidae) that form fish spawning aggregations (FSAs) are highly vulnerable to overfishing and often require site-specific approaches to management. Over 5-years (2009-2013), we conducted underwater visual censuses (UVC) at a well-known spawning site at Njari Island, Gizo, Western Province, Solomon Islands, that supports aggregations of squaretail coralgrouper (Plectropomus areolatus), camouflage grouper (Epinephelus polyphekadion) and brown-marbled grouper (E. fuscoguttatus). Findings show that while there were species-specific variations in the duration and timing of the spawning season, aggregation densities peaked from March to June, representing the main spawning season for all three species. For P. areolatus, gonad analysis from samples taken from 2008 to 2011 confirmed reproductive activity in support of density trends observed through UVC. Over the 5-year UVC monitoring period, FSA densities declined for P. areolatus and E. polyphekadion. Conversely, following the first year of monitoring, E. fuscoguttatus densities increased. These inter-specific differences may reflect variable responses to fishing as shown elsewhere, or for example, differences in recruitment success. In response to known declines in FSAs of these species, in 2018 the Solomon Islands government placed a nationwide ban on these species' harvest and sale between October and January. As this study shows, this ban does not encompass the peak aggregation period at Njari and will offer limited protection to other FSAs of these species that are known to vary in reproductive seasonality across the Solomon Islands. A more biologically meaningful and practical management strategy would be to implement a nationwide ban on the harvest and sale of these groupers each month between full and new moons when these FSAs form consistently throughout the country. Since effective management of FSAs typically requires a combined approach, spatial management that protects both spawning sites and reproductive migratory corridors is warranted

    The Fate of Chemically Dispersed and Untreated Crude Oil in Arctic Benthic Biota

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    Subtidal benthic biota were monitored for petroleum hydrocarbons following two experimental oil spills at Cape Hatt, N.W.T., Canada. In one spill oil was chemically dispersed into the water column, and in the other oil was released onto the water surface and allowed to strand on the shoreline. In addition to baseline samples, samples were collected immediately after the oil releases, two to three weeks after and one and two years after. Initial observations did not distinguish between effects of the surface and dispersed releases. Total oil content and hydrocarbon compositional analyses were conducted to investigate patterns of uptake and depuration for five different arctic species: Astarte borealis, Macoma calcarea, Mya truncata, Serripes groenlandicus and Strongylocentrotus droebachiensis. Filter-feeding species took up oil rapidly from the water column, while deposit-feeding species took up oil less rapidly from the sediments. All species depurated most of the oil after one year, but after two years the deposit feeders appeared to be taking up more oil from sediments contaminated by stranded oil from the surface oil release.Key words: oil, petroleum, determination, benthos, weathering, degradation, depuration, ArcticMots clés: pétrole, pétroliers, détermination, benthos, dégradation, décomposition, dépuration, arctique

    ECOLOGY OF THE IMAGE

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    We know very little about the ecology of our designed world. Contrary to all appearances, design is not about making objects. It is rather about structuring the conditions for life. Design is our second nature, naturalising changes in our ways of living. Yet it also conceals dangers and diminishes our sensitivity to respond to them. The security offered by the televisual image — and the solace of design's promise to remove all environmental risks — are fictions. Ecology of the Image is a critical exploration of idealism in design. Drawing on hermeneutic phenomenology, socio-cultural and design theory, it argues that design is not a value-free practice but structures epistemological attitudes into the world. Ideas are material elements of our environments. This thesis offers an explanation of how idealism circulates within the designed world, fashioning our minds, bodies and environments. The televisual is analysed as a normative phenomenon that inducts us into a way of seeing and understanding the world. Its vision of the affluent good life inspires and gives purpose to desire, and sustains what Manzini has called 'product based well being'. The thesis argues that the televisual puts us out of touch with the consequences of its vision; it diminishes our capacity for forethought. This results in the generation of unacknowledged, yet self-endangering environmental feedback. Environmental problems force us to take account of design's hidden rationales. Only at five minutes to midnight, for example, do we realise that the stock and supply of potable water is endangered. The problem is not so much this late recognition, but that design led us to believe in water's abundance. This situation demands the development of an ecological understanding of our designed worlds that can inform future actions. The sign, particularly as it has been mobilised in cultural theory, plays a leading role in this design situation and the perceptions it supports. The sign is utilised for its ability to denaturalise appearances — to 'read' design's claims on the world. Finally, the thesis turns to the designer-in-training in the process of acquiring instrumental skills and worldviews. It proposes a research strategy that inscribes environmental consciousness into the design process — situating the designer in the midst of semiotic and material worlds. Through its observational methodology it outlines ways of first understanding, then of intervening and generating changes in our 'ideal' world

    Extreme gravitational lensing in vicinity of Schwarzschild-de Sitter black holes

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    We have developed a realistic, fully general relativistic computer code to simulate optical projection in a strong, spherically symmetric gravitational field. The standard theoretical analysis of optical projection for an observer in the vicinity of a Schwarzschild black hole is extended to black hole spacetimes with a repulsive cosmological constant, i.e, Schwarzschild-de Sitter spacetimes. Influence of the cosmological constant is investigated for static observers and observers radially free-falling from the static radius. Simulations include effects of the gravitational lensing, multiple images, Doppler and gravitational frequency shift, as well as the intensity amplification. The code generates images of the sky for the static observer and a movie simulations of the changing sky for the radially free-falling observer. Techniques of parallel programming are applied to get a high performance and a fast run of the BHC simulation code

    G\"odel Type Metrics in Three Dimensions

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    We show that the G{\" o}del type Metrics in three dimensions with arbitrary two dimensional background space satisfy the Einstein-perfect fluid field equations. There exists only one first order partial differential equation satisfied by the components of fluid's velocity vector field. We then show that the same metrics solve the field equations of the topologically massive gravity where the two dimensional background geometry is a space of constant negative Gaussian curvature. We discuss the possibility that the G{\" o}del Type Metrics to solve the Ricci and Cotton flow equations. When the vector field uμu^{\mu} is a Killing vector field we finally show that the stationary G{\" o}del Type Metrics solve the field equations of the most possible gravitational field equations where the interaction lagrangian is an arbitrary function of the electromagnetic field and the curvature tensors.Comment: 17 page

    Fuchsian convex bodies: basics of Brunn--Minkowski theory

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    The hyperbolic space \H^d can be defined as a pseudo-sphere in the (d+1)(d+1) Minkowski space-time. In this paper, a Fuchsian group Γ\Gamma is a group of linear isometries of the Minkowski space such that \H^d/\Gamma is a compact manifold. We introduce Fuchsian convex bodies, which are closed convex sets in Minkowski space, globally invariant for the action of a Fuchsian group. A volume can be associated to each Fuchsian convex body, and, if the group is fixed, Minkowski addition behaves well. Then Fuchsian convex bodies can be studied in the same manner as convex bodies of Euclidean space in the classical Brunn--Minkowski theory. For example, support functions can be defined, as functions on a compact hyperbolic manifold instead of the sphere. The main result is the convexity of the associated volume (it is log concave in the classical setting). This implies analogs of Alexandrov--Fenchel and Brunn--Minkowski inequalities. Here the inequalities are reversed

    Scaling in Numerical Simulations of Domain Walls

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    We study the evolution of domain wall networks appearing after phase transitions in the early Universe. They exhibit interesting dynamical scaling behaviour which is not yet well understood, and are also simple models for the more phenomenologically acceptable string networks. We have run numerical simulations in two- and three-dimensional lattices of sizes up to 4096^3. The theoretically predicted scaling solution for the wall area density A ~ 1/t is supported by the simulation results, while no evidence of a logarithmic correction reported in previous studies could be found. The energy loss mechanism appears to be direct radiation, rather than the formation and collapse of closed loops or spheres. We discuss the implications for the evolution of string networks.Comment: 7pp RevTeX, 9 eps files (including six 220kB ones

    Strategies for the evolution of sex

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    We find that the hypothesis made by Jan, Stauffer and Moseley [Theory in Biosc., 119, 166 (2000)] for the evolution of sex, namely a strategy devised to escape extinction due to too many deleterious mutations, is sufficient but not necessary for the successful evolution of a steady state population of sexual individuals within a finite population. Simply allowing for a finite probability for conversion to sex in each generation also gives rise to a stable sexual population, in the presence of an upper limit on the number of deleterious mutations per individual. For large values of this probability, we find a phase transition to an intermittent, multi-stable regime. On the other hand, in the limit of extremely slow drive, another transition takes place to a different steady state distribution, with fewer deleterious mutations within the asexual population.Comment: RevTeX, 11 pages, multicolumn, including 12 figure

    Consistent Anisotropic Repulsions for Simple Molecules

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    We extract atom-atom potentials from the effective spherical potentials that suc cessfully model Hugoniot experiments on molecular fluids, e.g., O2O_2 and N2N_2. In the case of O2O_2 the resulting potentials compare very well with the atom-atom potentials used in studies of solid-state propertie s, while for N2N_2 they are considerably softer at short distances. Ground state (T=0K) and room temperatu re calculations performed with the new N−NN-N potential resolve the previous discrepancy between experimental and theoretical results.Comment: RevTeX, 5 figure
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