6,885 research outputs found

    Pumping and mode-locking techniques for near-infrared dye and colour centre lasers

    Get PDF
    Imperial Users onl

    Photometric Variability in Earthshine Observations

    Full text link
    The identification of an extrasolar planet as Earth-like will depend on the detection of atmospheric signatures or surface non-uniformities. In this paper we present spatially unresolved flux light curves of Earth for the purpose of studying a prototype extrasolar terrestrial planet. Our monitoring of the photometric variability of earthshine revealed changes of up to 23 % per hour in the brightness of Earth's scattered light at around 600 nm, due to the removal of specular reflection from the view of the Moon. This variability is accompanied by reddening of the spectrum, and results from a change in surface properties across the continental boundary between the Indian Ocean and Africa's east coast. Our results based on earthshine monitoring indicate that specular reflection should provide a useful tool in determining the presence of liquid water on extrasolar planets via photometric observations.Comment: To appear in Astrobiology 9(3). 17 pages, 3 figures, 1 tabl

    Pop up bottom seismic recording system

    No full text

    Manipulating biphotonic qutrits

    Get PDF
    Quantum information carriers with higher dimension than the canonical qubit offer significant advantages. However, manipulating such systems is extremely difficult. We show how measurement induced non-linearities can be employed to dramatically extend the range of possible transforms on biphotonic qutrits; the three level quantum systems formed by the polarisation of two photons in the same spatio-temporal mode. We fully characterise the biphoton-photon entanglement that underpins our technique, thereby realising the first instance of qubit-qutrit entanglement. We discuss an extension of our technique to generate qutrit-qutrit entanglement and to manipulate any bosonic encoding of quantum information.Comment: 4 pages, 4 figure

    An Examination Of Traditional Business Case Studies - Are They Outdated In Today's Technology Connected Environment?

    Get PDF
    The paper examines the effectiveness of using business case studies in today's Internet connected environment. The findings show that 87.8% of Harvard Business Review case solutions are commonly available on the Internet and that students can find an answer within 7.37 minutes. Based on this evidence, the authors contend that current use of business case studies as a learning tool requires a different approach. Standard case questions are no longer sufficient to ensure learning. Alternate approaches suggested are: students developing their own case analysis format, using local companies and data, the Real-Time Case Method, changing classifications and framing of cases, and contrasting case analysis