A new method to calibrate ionospheric pulse dispersion for UHE cosmic ray and neutrino detection using the Lunar Cherenkov technique

UHE particle detection using the lunar Cherenkov technique aims to detect nanosecond pulses of Cherenkov emission which are produced during UHE cosmic ray and neutrino interactions in the Moon's regolith. These pulses will reach Earth-based telescopes dispersed, and therefore reduced in amplitude, due to their propagation through the Earth's ionosphere. To maximise the received signal to noise ratio and subsequent chances of pulse detection, ionospheric dispersion must therefore be corrected, and since the high time resolution would require excessive data storage this correction must be made in real time. This requires an accurate knowledge of the dispersion characteristic which is parameterised by the instantaneous Total Electron Content (TEC) of the ionosphere. A new method to calibrate the dispersive effect of the ionosphere on lunar Cherenkov pulses has been developed for the LUNASKA lunar Cherenkov experiments. This method exploits radial symmetries in the distribution of the Moon's polarised emission to make Faraday rotation measurements in the visibility domain of synthesis array data (i. e. instantaneously). Faraday rotation measurements are then combined with geomagnetic field models to estimate the ionospheric TEC. This method of ionospheric calibration is particularly attractive for the lunar Cherenkov technique as it may be used in real time to estimate the ionospheric TEC along a line-of-sight to the Moon and using the same radio telescope.Comment: 4 pages, 2 figures, Proceedings of ARENA 2010, Nantes, France; doi:10.1016/j.nima.2010.10.12

Beyond technology and finance: pay-as-you-go sustainable energy access and theories of social change

Two-thirds of people in sub-Saharan Africa lack access to electricity, a precursor of poverty reduction and development. The international community has ambitious commitments in this regard, e.g. the UN's Sustainable Energy for All by 2030. But scholarship has not kept up with policy ambitions. This paper operationalises a sociotechnical transitions perspective to analyse for the first time the potential of new, mobileenabled, pay-as-you-go approaches to financing sustainable energy access, focussing on a case study of pay-as-you-go approaches to financing solar home systems in Kenya. The analysis calls into question the adequacy of the dominant, two-dimensional treatment of sustainable energy access in the literature as a purely financial/technology, economics/ engineering problem (which ignores sociocultural and political considerations) and demonstrates the value of a new research agenda that explicitly attends to theories of social change – even when, as in this paper, the focus is purely on finance. The paper demonstrates that sociocultural considerations cut across the literature's traditional two-dimensional analytic categories (technology and finance) and are material to the likely success of any technological or financial intervention. It also demonstrates that the alignment of new payas- you-go finance approaches with existing sociocultural practices of paying for energy can explain their early success and likely longevity relative to traditional finance approaches

Local government and society in early modern England: Hertfordshire and Essex, C. 1590-- 1630

This administrative and social history of Hertfordshire and Essex tracks the careers, social relationships, and personal tribulations of justices of the peace and other county officials from 1590 through 1630. The study addresses the nature of the relationship between local government and the central government, the social structure of the two counties as reflected in the annual lists of the justices of the peace, and any administrative or social connections between Hertfordshire and Essex. Office holding was not only an administrative duty but also intertwined the lives of real people. Did local officials rise or fall because of central government actions, or did inter-county faction drive the successes or failures of the ruling elite? Was there any underlying social connection among the gentry of the two contiguous counties that influenced local administration? Finally, how did local government function? What role did it play on the lives of the people? The study was accomplished through first examining the annual commissions of the peace for each county; from these lists, information was compiled regarding the nature of local office holding as well as the individuals likely to serve in county government. Manuscript sources revealed the social backgrounds and personal stories of individual justices of the peace. Local records showed the workings of county administration and the jurisdiction of the shires’ ruling elite. Other printed sources tied the counties to the Crown and explored issues of religion, economics, and politics. Local governance in Hertfordshire and Essex was successful to the extent that it provided order and stability to the Crown, the ruling elite, and the inhabitants of the counties. For the most part, the magistracy did fulfill this function and the result was a marked continuity in local government and society. Although disorder could erupt on occasion, changes initiated by the central government caused the most tension in the shires. By the late-1620’s, the lords lieutenant, their deputies, and the justices of the peace were stretched to the breaking point by the open-ended threat of economic, political, religious, and social innovations imposed from above

Pion Production in 300 Gev Nucleon-Nucleon Collisions

Recent theoretical investigations of high energy nucleon-nucleon collisions support the two-center model of multiple meson production as discussed by Ciok, et al. To facilitate a prediction of the most probable distribution of shower particles as a function of laboratory energy, Farley's kinematical treatment of the "two-fireball" model is employed. A statistical determination of the multiplicity of pion (including neutrals) production per collision is assumed to be valid with possible corrections suggested through restrictions imposed by experimental values of the inelasticity, Κ_π

On the Unpulsed Radio Emission from J0737-3039

The double pulsar system J0737-3039 appears associated with a continuous radio emission, nearly three times stronger than that of the two pulsars together. If such an emission comes from a tranparent cloud its spatial extent (> 10^13 cm) should be substantially larger than the orbital separation. Assuming homogeneity and equipartition, the cloud magnetic field is 0.03 G and the electron characteristic energy ~ 60 MeV. This is consistent with supposing that relativistic electrons produced in the shock formed by the interaction of the more luminous pulsar wind with the magnetosphere of the companion flow away filling a larger volume. Alternatively, the unpulsed emission may directly come from the bow shock if some kind of coherent mechanism is at work. Possible observational signatures that can dicriminate between the two pictures are shortly discussed.Comment: 4 pages, no figures, accepted for publication in A&A (Letters

Operational experience and design recommendations for teleoperated flight hardware

Teleoperation (remote manipulation) will someday supplement/minimize astronaut extravehicular activity in space to perform such tasks as satellite servicing and repair, and space station construction and servicing. This technology is being investigated by NASA with teleoperation of two space-related tasks having been demonstrated at the Oak Ridge National Lab. The teleoperator experiments are discussed and the results of these experiments are summarized. The related equipment design recommendations are also presented. In addition, a general discussion of equipment design for teleoperation is also presented

Radio Emission Signatures in the Crab Pulsar

Our high time resolution observations of individual pulses from the Crab pulsar show that both the time and frequency signatures of the interpulse are distinctly different from those of the main pulse. Main pulses can occasionally be resolved into short-lived, relatively narrow-band nanoshots. We believe these nanoshots are produced by soliton collapse in strong plasma turbulence. Interpulses at centimeter wavelengths are very different. Their dynamic spectrum contains regular, microsecond-long emission bands. We have detected these bands, proportionately spaced in frequency, from 4.5 to 10.5 GHz. The bands cannot easily be explained by any current theory of pulsar radio emission; we speculate on possible new models.Comment: 26 pages, 10 figures, to appear in Ap