1,480 research outputs found

    Lunar penetrometer Patent

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    Development and characteristics of pentrometer for measuring physical properties of lunar surfac

    Exchange interactions and relaxation in paramagnets

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    This thesis presents some investigations into a variety of paramagnetic systems. Electron paramagnetic resonance is often used to investigate the behaviour of paramagnetic ions present as substitutional impurities in diamagnetic host crystals. Measurements have been carried out at liquid helium temperatures on single crystals of aluminium acetylacetonate doped to 2% with ruthenium 3+ ions. The spectrum at nitrogen temperatures has been reported by Jarrett (1957) who found two ruthenium sites

    Demolishing the Present to Sell off the Future? The Emergence of ‘Financialized Municipal Entrepreneurialism’ in London

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    This article introduces a new mode of urban entrepreneurialism in London through a study of the state-executed, speculative development and financialization of public land. In response to an intensifying housing crisis and austerity-imposed fiscal constraints, municipalities in London are devising entrepreneurial solutions to deliver more housing. Among these ‘solutions’ can be found the early signs of the state-executed financialization of public housing in the UK with the use of speculative council-owned special purpose vehicles (SPVs) that replace existing public housing stock with mixed-tenure developments, creating ambiguous public/private tenancies that function as homes and the basis for liquid financial assets. Drawing together parallel literatures on the financialization of urban governance and housing, and combining these with original empirical research, we situate these developments in contrast to earlier modes of governance, identifying a distinct mode of entrepreneurial governance in London: financialized municipal entrepreneurialism. The local state is no longer merely the enabler—limited to providing strategic oversight of the private sector—but financializes its practice in a reimagined commercialized interventionism, as property speculator. This article concludes that while the architects of this new mode of entrepreneurialism extol the increased capacity and control it provides, any such gains must be set against longer-term financial, democratic and political risks

    Sub-arcsecond imaging of the radio continuum and neutral hydrogen in the Medusa merger

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    We present sub-arcsecond, Multi-Element Radio Linked Interferometer (MERLIN) observations of the decimetre radio continuum structure and neutral hydrogen (HI) absorption from the nuclear region of the starburst galaxy NGC 4194 (the Medusa Merger). The continuum structure of the central kiloparsec of the Medusa has been imaged, revealing a pair of compact radio components surrounded by more diffuse, weak radio emission. Using the constraints provided by these observations and those within the literature we conclude that the majority of this radio emission is related to the ongoing star-formation in this merger system. With these observations we also trace deep HI absorption across the detected radio continuum structure. The absorbing HI gas structure exhibits large variations in column densities. The largest column densities are found toward the south of the nuclear radio continuum, co-spatial with both a nuclear dust lane and peaks in 12^{12}CO (1->0) emission. The dynamics of the HI absorption, which are consistent with lower resolution 12^{12}CO emission observations, trace a shallow north-south velocity gradient of ~320km/s/kpc. This gradient is interpreted as part of a rotating gas structure within the nuclear region. The HI and CO velocity structure, in conjunction with the observed gas column densities and distribution, is further discussed in the context of the fuelling and gas physics of the ongoing starburst within the centre of this merger.Comment: 12 pages, 5 figures, to appear in A&

    Excavations at the Viking Barrow Cemetery at Heath Wood, Ingleby, Derbyshire

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    The cemetery at Heath Wood, Ingleby, Derbyshire, is the only known Scandinavian cremation cemetery in the British Isles. It comprises fifty-nine barrows, of which about one-third have been excavated on previous occasions, although earlier excavators concluded that some were empty cenotaph mounds. From 1998 to 2000 three barrows were examined. Our investigations have suggested that each of the barrows contained a burial, although not all contain evidence of a pyre. A full report of the 1998-2000 excavations is provided, alongside a summary of the earlier finds. The relationship of Heath Wood to the neighbouring site at Repton is examined, in order to understand its significance for the Scandinavian settlement of the Danelaw. It is concluded that Heath Wood may have been a war cemetery of the Viking Great Army of AD 873-8

    ALMA observations of 99 GHz free-free and H40α\alpha line emission from star formation in the centre of NGC 253

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    We present Atacama Large Millimeter/submillimeter Array observations of 99.02 GHz free-free and H40α\alpha emission from the centre of the nearby starburst galaxy NGC 253. We calculate electron temperatures of 3700-4500 K for the photoionized gas, which agrees with previous measurements. We measure a photoionizing photon production rate of (3.2±0.2)×1053(3.2\pm0.2)\times10^{53} s−1^{-1} and a star formation rate of 1.73±0.121.73\pm0.12 M⊙_\odot yr−1^{-1} within the central 20×\times10 arcsec, which fall within the broad range of measurements from previous millimetre and radio observations but which are better constrained. We also demonstrate that the dust opacities are ~3 dex higher than inferred from previous near-infrared data, which illustrates the benefits of using millimetre star formation tracers in very dusty sources.Comment: 5 pages, 3 figures, accepted for publication in MNRAS Letter

    Deep MERLIN 5GHz Radio Imaging of Supernova Remnants in the M82 Starburst

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    The results of an extremely deep, 8-day long observation of the central kpc of the nearby starburst galaxy M82 using MERLIN (Multi-Element Radio Linked Interferometer Network) at 5 GHz are presented. The 17E-06 Jy/beam, rms noise level in the naturally weighted image make it the most sensitive high resolution radio image of M82 made to date. Over 50 discrete sources are detected, the majority of which are supernova remnants, but with 13 identified as HII regions. Sizes, flux densities and radio brightnesses are given for all of the detected sources, which are all well resolved with a majority showing shell or partial shell structures. Those sources within the sample which are supernova remnants have diameters ranging from 0.3 to 6.7 pc, with a mean size of 2.9 pc. From a comparison with previous MERLIN 5 GHz observations made in July 1992, which gives a 9.75 year timeline, it has been possible to measure the expansion velocities of ten of the more compact sources, eight of which have not been measured before. These derived expansion velocities range between 2200 and 10500 km/s.Comment: 34 pages, 10 figures. Accepted by MNRA
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