159 research outputs found
Twin approaches to research: the Penn State and Flinders experience
Two universities, The Pennsylvania State University in the United States and The Flinders University of South Australia, like many other higher education institutions, are developing online distance education programs. This paper reports on two approaches to offering a research methods topic at the postgraduate level, approaches that were determined in part by learners and their environment, which in turn determined modes of delivery. The modes of learning, development of learning resources, topic evaluation and feedback, and the lessons learned from offering the two research topics in an international context provide pointers to other higher education institutions planning to offer courses by flexible delivery. [Author abstract
Search for a Standard Explanation of the Pioneer Anomaly
The data from Pioneer 10 and 11 shows an anomalous, constant, Doppler
frequency drift that can be interpreted as an acceleration directed towards the
Sun of a_P = (8.74 \pm 1.33) x 10^{-8} cm/s^2. Although one can consider a new
physical origin for the anomaly, one first must investigate the contributions
of the prime candidates, which are systematics generated on board. Here we
expand upon previous analyses of thermal systematics. We demonstrate that
thermal models put forth so far are not supported by the analyzed data.
Possible ways to further investigate the nature of the anomaly are proposed.Comment: Changes made for publicatio
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Antimicrobial Activity of the crude extracts and fractions of \u3cem\u3eFicus thonningii\u3c/em\u3e (Blume) on Isolates from Urinary Tract Infections
The Anomalous Trajectories of the Pioneer Spacecraft
Because of their unique designs, the Pioneer 10 and 11 spacecraft have
provided the cleanest Doppler, deep-space navigation data. Analysis of this
data can be interpreted as showing an anomalous acceleration of these craft
directed towards the Sun of . The
background of this discovery and the significance of the result are discussed.Comment: 5 pages, 2 figures, to be published in the Proceedings of the Second
Meeting on CPT and Lorentz Symmetr
Anderson et al. Reply (to the Comment by Murphy on Pioneer 10/11)
We conclude that Murphy's proposal (radiation of the power of the main-bus
electrical systems from the rear of the craft) can not explain the anomalous
Pioneer acceleration.Comment: LaTex, 3 pages, Phys. Rev. Lett. (to be published
Anderson et al. Reply (to the Comment by Katz on Pioneer 10/11)
We conclude that Katz's proposal (anisotropic heat reflection off of the back
of the spacecraft high-gain antennae, the heat coming from the RTGs) does not
provide enough power and so can not explain the Pioneer anomaly.Comment: LaTex, 3 pages, Phys. Rev. Lett. (to be published
The Apparent Anomalous, Weak, Long-Range Acceleration of Pioneer 10 and 11
Recently we reported that radio Doppler data generated by NASA's Deep Space
Network (DSN) from the Pioneer 10 and 11 spacecraft indicate an apparent
anomalous, constant, spacecraft acceleration with a magnitude cm s, directed towards the Sun (gr-qc/9808081). Analysis of
similar Doppler and ranging data from the Galileo and Ulysses spacecraft
yielded ambiguous results for the anomalous acceleration, but it was useful in
that it ruled out the possibility of a systematic error in the DSN Doppler
system that could easily have been mistaken as a spacecraft acceleration. Here
we present some new results, including a critique suggestions that the
anomalous acceleration could be caused by collimated thermal emission. Based
partially on a further data for the Pioneer 10 orbit determination, the data
now spans January 1987 to July 1998, our best estimate of the average Pioneer
10 acceleration directed towards the Sun is cm
s.Comment: Latex, 7 pages and 2 figures. Invited talk at the XXXIV-th Rencontres
de Moriond Meeting on Gravitational Waves and Experimental Gravity. Les Arcs,
Savoi, France (January 23-30,1999). Corrected typo
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Antimicrobial activity of Extracts and Fractions of the Leaves of \u3cem\u3eFicus thonningii\u3c/em\u3e (Blume) and \u3cem\u3eFicus natalensis\u3c/em\u3e (Hochst) on Methicillin-Resistant \u3cem\u3eStaphylococcus aureus\u3c/em\u3e (MRSA)
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