1,494 research outputs found
Lunar penetrometer Patent
Development and characteristics of pentrometer for measuring physical properties of lunar surfac
Exchange interactions and relaxation in paramagnets
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
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
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 CO (1->0) emission. The dynamics of the HI absorption,
which are consistent with lower resolution 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
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 H40 line emission from star formation in the centre of NGC 253
We present Atacama Large Millimeter/submillimeter Array observations of 99.02
GHz free-free and H40 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 s and
a star formation rate of M yr within the central
2010 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
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
- …