587 research outputs found
Boxed up and locked up, safe and tight! Making the case for unattended electronic locker bank logistics for an innovative solution to NHS hospital supplies (UK)
YesThe lack of separation between urgent and non-urgent medical goods
encourages sub-optimal vehicle fleet operations owing to the time critical
nature of urgent items. An unattended electronic locker bank, to which
individual urgent items can be delivered thereby separating urgent and
non-urgent supply, was proposed for the Great Ormond Street Hospital in
London, UK. This concept was quantified using âbasicâ and âintuitiveâ hill
climbing optimisation models; and qualitatively using staff interviews and
expert reviews. Results indicated that a locker bank with a fixed height (1.7 m)
and depth (0.8 m) required a length of 4 m (basic model) and 3.63 m (intuitive
model), to accommodate 100% of urgent consignments for a typical week.
Staff interviews indicated the wider benefits such as staff personal deliveries
A prototype model for evaluating SKA-LOW station calibration
The Square Kilometre Array telescope at low-frequency (SKA-Low) will be a phased array telescope supporting a wide
range of science cases covering the frequency band 50 - 350 MHz, while at the same time asking for high sensitivity and
excellent characteristics. These extremely challenging requirements resulted in a design using 512 groups of 256 log
periodic dual polarized antennas each (where each group is called âstationâ), for a total of 131072 antennas. The 512
stations are randomly distributed mostly within a dense area around the centre of the SKA-Low, and then in 3 arms having
16 station clusters each.
In preparation for the SKA Phase 1 (SKA1) System Critical Design Review (CDR), prototype stations were deployed at
the Murchison Radio-astronomy Observatory (MRO) site (Western Australia) near the Murchison Widefield Array
(MWA) radio telescope. The project involved multiple parties in an International collaboration building and testing
different prototypes of the SKA1-Low station near the actual site. This resulted in both organisational and logistic
challenges typical of a deployment of the actual telescope.
The test set-up involved a phased build-up of the complex station of log-periodic antennas, by starting from the deployment
of 48 antennas and related station signal processing (called AAVS1.5, where AAVS stands for Aperture Array Verification
System), followed by expansion to a full station (AAVS2.0). As reference a station with dipole antennas EDA2 (EDA:
Engineering Development Array) was deployed. This test set-up was used for an extensive test and evaluation programme.
All test antenna configurations were simulated in detail by electromagnetic (EM) models, and the prediction of the models
was further verified by appropriate tests with a drone-based radio frequency source. Astronomical observations on Sun
and galaxy transit were performed with calibrated stations of both EDA2, AAVS1.5 and AAVS2.0. All 3 configurations
were calibrated. EM modelling and calibration results for the full station AAVS2.0 and EM verification for the AAVS1.5
station are presented.
The comparisons between the behaviour of the log-periodic antennas and the dipoles have advanced our understanding the
calibration quality and the technological maturity of the future SKA1-Low array
Screening a protein kinase inhibitor library against <i>Plasmodium falciparum</i>
Abstract Background Protein kinases have been shown to be key drug targets, especially in the area of oncology. It is of interest to explore the possibilities of protein kinases as a potential target class in Plasmodium spp., the causative agents of malaria. However, protein kinase biology in malaria is still being investigated. Therefore, rather than assaying against individual protein kinases, a library of 4731 compounds with protein kinase inhibitor-like scaffolds was screened against the causative parasite, Plasmodium falciparum. This approach is more holistic and considers the whole kinome, making it possible to identify compounds that inhibit more than one P. falciparum protein kinase, or indeed other malaria targets. Results As a result of this screen, 9 active compound series were identified; further validation was carried out on 4 of these series, with 3 being progressed into hits to lead chemistry. The detailed evaluation of one of these series is described. Discussion This screening approach proved to be an effective way to identify series for further optimisation against malaria. Compound optimisation was carried out in the absence of knowledge of the molecular target. Some of the series had to be halted for various reasons. Mode of action studies to find the molecular target may be useful when problems prevent further chemical optimisation. Conclusions Progressible series were identified through phenotypic screening of a relatively small focused kinase scaffold chemical library
SN 2009kf : a UV bright type IIP supernova discovered with Pan-STARRS 1 and GALEX
We present photometric and spectroscopic observations of a luminous type IIP
Supernova 2009kf discovered by the Pan-STARRS 1 (PS1) survey and detected also
by GALEX. The SN shows a plateau in its optical and bolometric light curves,
lasting approximately 70 days in the rest frame, with absolute magnitude of M_V
= -18.4 mag. The P-Cygni profiles of hydrogen indicate expansion velocities of
9000km/s at 61 days after discovery which is extremely high for a type IIP SN.
SN 2009kf is also remarkably bright in the near-ultraviolet (NUV) and shows a
slow evolution 10-20 days after optical discovery. The NUV and optical
luminosity at these epochs can be modelled with a black-body with a hot
effective temperature (T ~16,000 K) and a large radius (R ~1x10^{15} cm). The
bright bolometric and NUV luminosity, the lightcurve peak and plateau duration,
the high velocities and temperatures suggest that 2009kf is a type IIP SN
powered by a larger than normal explosion energy. Recently discovered high-z
SNe (0.7 < z < 2.3) have been assumed to be IIn SNe, with the bright UV
luminosities due to the interaction of SN ejecta with a dense circumstellar
medium (CSM). UV bright SNe similar to SN 2009kf could also account for these
high-z events, and its absolute magnitude M_NUV = -21.5 +/- 0.5 mag suggests
such SNe could be discovered out to z ~2.5 in the PS1 survey.Comment: Accepted for publication in APJ
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The social consequences of minor innovations in construction
Innovation studies in construction focus on a desire to increase economics and efficiency at a large scale. This has resulted in a skewed perspective that sees only major corporations with substantial R&D resources, complex projects, or national interests at the heart of innovation. By adopting anthropological methods, it becomes possible to examine the two aims of this paper: to demonstrate that an accumulation of minor innovations can have significant consequences; and to show that these are inherently social rather than purely economic. Results come from fieldwork studying the improvisatory house-building practices of the Kelabit people of rural Borneo, tracing changes to the technologies used for roofing and foundations, and describes how these are mutually entangled with new social structures. The conclusion is that we should think more broadly about the forms and effects of innovation in construction, and recognise the significance of improvisation at the level of the individual or small group
The giant lobes of Centaurus A observed at 118 MHz with the Murchison Widefield Array
We present new wide-field observations of Centaurus A (Cen A) and the surrounding region at 118MHz with the Murchison Widefield Array (MWA) 32-tile prototype, with which we investigate the spectral-index distribution of Cen A's giant radio lobes.We compa
SkyMapper and the Southern Sky Survey
This paper presents the design and science goals for the SkyMapper telescope.
SkyMapper is a 1.3m telescope featuring a 5.7 square degree field-of-view
Cassegrain imager commissioned for the Australian National University's
Research School of Astronomy and Astrophysics. It is located at Siding Spring
Observatory, Coonabarabran, NSW, Australia and will see first light in late
2007. The imager possesses 16kx16k 0.5 arcsec pixels. The primary scientific
goal of the facility is to perform the Southern Sky Survey, a six colour and
multi-epoch (4 hour, 1 day, 1 week, 1 month, 1 year sampling) photometric
survey of the southerly 2pi steradians to g~23 mag. The survey will provide
photometry to better than 3% global accuracy and astrometry to better than 50
mas. Data will be supplied to the community as part of the Virtual Observatory
effort. The survey will take five years to complete
On the complete classification of the unitary N=2 minimal superconformal field theories
Aiming at a complete classification of unitary N=2 minimal models (where the
assumption of space-time supersymmetry has been dropped), it is shown that each
modular invariant candidate of a partition function for such a theory is indeed
the partition function of a minimal model. A family of models constructed via
orbifoldings of either the diagonal model or of the space-time supersymmetric
exceptional models demonstrates that there exists a unitary N=2 minimal model
for every one of the allowed partition functions in the list obtained from
Gannon's work.
Kreuzer and Schellekens' conjecture that all simple current invariants can be
obtained as orbifolds of the diagonal model, even when the extra assumption of
higher-genus modular invariance is dropped, is confirmed in the case of the
unitary N=2 minimal models by simple counting arguments.Comment: 53 pages; Latex; minor changes in v2: intro expanded, references
added, typos corrected, footnote added on p31; renumbering of sections; main
theorem reformulated for clarity, but contents unchanged. Minor revisions in
v3: typos corrected, footnotes 5, 6 added, lemma 1 and section 3.3.2
rewritten for greater generality, section 3.3 review removed. To appear in
Comm. Math. Phy
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