4,249 research outputs found

    Telecommunications and data acquisition systems support for Voyager missions to Jupiter and Saturn, 1972-1981, prelaunch through Saturn encounter

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    The Deep Space Network has supported the Voyager Project for approximately nine years, during which time implementation, testing, and operational support was provided. Four years of this time involved testing prior to launch; the final five years included network operations support and additional network implementation. Intensive and critical support intervals included launch and four planetary encounters. The telecommunications and data acquisition support for the Voyager Missions to Jupiter and Saturn are summarized

    Multiwavelength Observations of the Hot DB Star PG 0112+104

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    We present a comprehensive multiwavelength analysis of the hot DB white dwarf PG 0112+104. Our analysis relies on newly-acquired FUSE observations, on medium-resolution FOS and GHRS data, on archival high-resolution GHRS observations, on optical spectrophotometry both in the blue and around Halpha, as well as on time-resolved photometry. From the optical data, we derive a self-consistent effective temperature of 31,300+-500 K, a surface gravity of log g = 7.8 +- 0.1 (M=0.52 Msun), and a hydrogen abundance of log N(H)/N(He) < -4.0. The FUSE spectra reveal the presence of CII and CIII lines that complement the previous detection of CII transitions with the GHRS. The improved carbon abundance in this hot object is log N(C)/N(He) = -6.15 +- 0.23. No photospheric features associated with other heavy elements are detected. We reconsider the role of PG 0112+104 in the definition of the blue edge of the V777 Her instability strip in light of our high-speed photometry, and contrast our results with those of previous observations carried out at the McDonald Observatory.Comment: 10 pages in emulateapj, 9 figures, accepted for publication in Ap

    Ion cyclotron resonance studies of radiative and dissociative electron attachment processes at low pressures

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    Ion cyclotron resonance spectroscopy is used to measure nondissociative electron attachment rate constants for C6F6 (perfluorobenzene), C7F8 (perfluorotoluene), c-C4F8 (perfluorocyclobutane), and C7F14 (perfluoromethylcyclohexane) at low pressure (<10−6 Torr). Infrared emission is assumed to stabilize excited species leading to long-lived molecular negative ions. Combining the present data with negative ion lifetimes measured at low pressures by time-of-flight methods and electron attachment rates measured at high pressures in swarm experiments allows estimates of radiative lifetimes to be made. These all fall in the range from 0.4 to 1.5 msec, which are typical of infrared radiative lifetimes. Data are also presented for dissociative electron attachment to CCl4, where the rate limiting step is shown to be thermalization of the electron energy distribution. A number of different buffer gases are examined and the ion cyclotron resonance results extrapolate to yield the attachment rate measured in high pressure swarm experiments

    Virtue and austerity

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    Virtue ethics is often proposed as a third way in health-care ethics, that while consequentialism and deontology focus on action guidelines, virtue focuses on character; all three aim to help agents discern morally right action although virtue seems to have least to contribute to political issues, such as austerity. I claim: (1) This is a bad way to characterize virtue ethics. The 20th century renaissance of virtue ethics was first proposed as a response to the difficulty of making sense of ‘moral rightness’ outside a religious context. For Aristotle the right action is that which is practically best; that means best for the agent in order to live a flourishing life.There are no moral considerations besides this. (2) Properly characterized, virtue ethics can contribute to discussion of austerity. A criticism of virtue ethics is that fixed characteristics seem a bad idea in ever-changing environments; perhaps we should be generous in prosperity, selfish in austerity. Furthermore, empirical evidence suggests that people indeed do change with their environment. However, I argue that virtues concern fixed values not fixed behaviour; the values underlying virtue allow for different behaviour in different circumstances: in austerity, virtues still give the agent the best chance of flourishing. Two questions arise. (a) In austere environments might not injustice help an individual flourish by, say, obtaining material goods? No, because unjust acts undermine the type of society the agent needs for flourishing. (b) What good is virtue to those lacking the other means to flourish? The notion of degrees of flourishing shows that most people would benefit somewhat from virtue. However, in extreme circumstances virtue might harm rather than benefit the agent: such circumstances are to be avoided; virtue ethics thus has a political agenda to enable flourishing. This requires justice, a fortiori when in austerity

    Resilience to climate shocks in the tropics

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    This focus collection on resilience to climate shocks in the tropics draws together 16 papers that predominantly examine the impacts of, and responses to, the 2015/2016 El Niño-Southern Oscillation event, in a range of contexts. This introductory synthesis contextualises the collection of papers by reviewing important concepts and highlighting some important insights that emerge from the collection. The papers in this collection collectively highlight: the value of longitudinal and interdisciplinary research in understanding both the roots of, and responses to, resilience challenges; the critical interaction between climatic and land-use changes; and the ways in which governance arrangements underpin societal decision-making across a range of scales and contexts to shape resilience

    Teamwork training in sport:A pilot intervention study

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    The purpose of this study was to test the efficacy of a novel team building intervention that targets teamwork in sport. Using a 10-week pilot nonrandomized controlled intervention design, 12 interdependent sports teams comprising 187 athletes were assigned to one of two conditions: an experimental condition in which teams participated in two teamwork training sessions at Weeks 2 and 6 of the study (6 teams, 94 athletes) or a no-training control condition (6 teams, 93 athletes). Teamwork was measured at Weeks 1, 5, and 10 of the study. Overall, significant improvements in teamwork were shown for the experimental teams from baseline to Week 5; these effects were maintained through Week 10 of the study. In contrast, no significant changes in teamwork were observed for teams in the control condition over these 10 weeks. The results provide evidence that teamwork training can enhance the extent to which members of a sports team work effectively together
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