990 research outputs found

    Ulysses

    Get PDF
    The DSN (Deep Space Network) mission support requirements for Ulysses are summarized. The primary goal of the Ulysses mission is to explore the Sun, its environment, and possible links between solar variability and terrestrial weather and climate. The Ulysses spacecraft will be injected into an interplanetary orbit toward Jupiter after which the spacecraft travels in a heliocentric, out-of-ecliptic orbit with high heliographic inclination. The Ulysses mission objectives are outlined and the DSN support requirements are defined through the presentation of tables and narratives describing the spacecraft flight profile; DSN support coverage; frequency assignments; support parameters for telemetry, command and support systems; and tracking support responsibility

    Songwriting and Transformation: The Subjective Experience of Sharing Self Through Song

    Get PDF
    This qualitative heuristic study explored the subjective experience of transformation resulting from the practice of songwriting in nonclinical populations, through semistructured interviews with 12 songwriters, 6 men and 6 women, aged 35-69. Thematic content analysis yielded 6 top-level themes: Connecting, Communicating, Wellbeing, Affirmation, Personal Growth, and Making A Difference. Subthemes of Connecting reflect a wide variety of transpersonal experiences. The Communicating subthemes capture ways in which songwriting afforded participants a language superior to speech for Expressing Feelings, Sharing Self, and Sending A Message. Participants reported Personal Growth, expressed through subthemes Processing Experience (making meaning of painful material) and Empowerment. Learning explicitly that one of their songs had had a significant impact on a listener was the mostly strongly articulated transformative experience for participants, described in Making A Difference. The findings support models of transformation in the expressive arts literature; through transpersonal encounters in liminality, both songwriter and listeners are transformed

    Linseed growing in the Ord River valley

    Get PDF
    Experimental work with linseed at the Kimberley Research Station began in 1952 and has been intensified in the last four years. Fertiliser requirements and methods of land preparation, sowing, irrigation and weed control have been established. Suitable varieties have been selected. Farm-scale crops have been grown in the area and, although cotton is very much more remunerative as an establishment crop, it is expected that linseed will ultimately have a place in the Ord irrigation scheme

    The incidence and classification of cider yeasts

    Get PDF

    Pre-Existing Superbubbles as the Sites of Gamma-Ray Bursts

    Get PDF
    According to recent models, gamma-ray bursts apparently explode in a wide variety of ambient densities ranging from ~ 10^{-3} to 30 cm^{-3}. The lowest density environments seem, at first sight, to be incompatible with bursts in or near molecular clouds or with dense stellar winds and hence with the association of gamma-ray bursts with massive stars. We argue that low ambient density regions naturally exist in areas of active star formation as the interiors of superbubbles. The evolution of the interior bubble density as a function of time for different assumptions about the evaporative or hydrodynamical mass loading of the bubble interior is discussed. We present a number of reasons why there should exist a large range of inferred afterglow ambient densities whether gamma-ray bursts arise in massive stars or some version of compact star coalescence. We predict that many gamma-ray bursts will be identified with X-ray bright regions of galaxies, corresponding to superbubbles, rather than with blue localized regions of star formation. Massive star progenitors are expected to have their own circumstellar winds. The lack of evidence for individual stellar winds associated with the progenitor stars for the cases with afterglows in especially low density environments may imply low wind densities and hence low mass loss rates combined with high velocities. If gamma-ray bursts are associated with massive stars, this combination might be expected for compact progenitors with atmospheres dominated by carbon, oxygen or heavier elements, that is, progenitors resembling Type Ic supernovae.Comment: 14 pages, no figures, submitted to The Astrophysical Journa

    Kimberley Research Station progress report, 1964 : oil crops

    Get PDF
    INVESTIGATIONS on the adaptation of a range of oil crops to the Ord River environment have been in progress since the early years of the Station

    Extension of nano-confined DNA: quantitative comparison between experiment and theory

    Get PDF
    The extension of DNA confined to nanochannels has been studied intensively and in detail. Yet quantitative comparisons between experiments and model calculations are difficult because most theoretical predictions involve undetermined prefactors, and because the model parameters (contour length, Kuhn length, effective width) are difficult to compute reliably, leading to substantial uncertainties. Here we use a recent asymptotically exact theory for the DNA extension in the "extended de Gennes regime" that allows us to compare experimental results with theory. For this purpose we performed new experiments, measuring the mean DNA extension and its standard deviation while varying the channel geometry, dye intercalation ratio, and ionic buffer strength. The experimental results agree very well with theory at high ionic strengths, indicating that the model parameters are reliable. At low ionic strengths the agreement is less good. We discuss possible reasons. Our approach allows, in principle, to measure the Kuhn length and effective width of a single DNA molecule and more generally of semiflexible polymers in solution.Comment: Revised version, 6 pages, 2 figures, 1 table, supplementary materia

    On the properties of fractal cloud complexes

    Full text link
    We study the physical properties derived from interstellar cloud complexes having a fractal structure. We first generate fractal clouds with a given fractal dimension and associate each clump with a maximum in the resulting density field. Then, we discuss the effect that different criteria for clump selection has on the derived global properties. We calculate the masses, sizes and average densities of the clumps as a function of the fractal dimension (D_f) and the fraction of the total mass in the form of clumps (epsilon). In general, clump mass does not fulfill a simple power law with size of the type M_cl ~ (R_cl)**(gamma), instead the power changes, from gamma ~ 3 at small sizes to gamma<3 at larger sizes. The number of clumps per logarithmic mass interval can be fitted to a power law N_cl ~ (M_cl)**(-alpha_M) in the range of relatively large masses, and the corresponding size distribution is N_cl ~ (R_cl)**(-alpha_R) at large sizes. When all the mass is forming clumps (epsilon=1) we obtain that as D_f increases from 2 to 3 alpha_M increases from ~0.3 to ~0.6 and alpha_R increases from ~1.0 to ~2.1. Comparison with observations suggests that D_f ~ 2.6 is roughly consistent with the average properties of the ISM. On the other hand, as the fraction of mass in clumps decreases (epsilon<1) alpha_M increases and alpha_R decreases. When only ~10% of the complex mass is in the form of dense clumps we obtain alpha_M ~ 1.2 for D_f=2.6 (not very different from the Salpeter value 1.35), suggesting this a likely link between the stellar initial mass function and the internal structure of molecular cloud complexes.Comment: 32 pages, 13 figures, 1 table. Accepted for publication in Ap
    corecore