3,372 research outputs found
Medium-term performance and maintenance of SUDS:a case-study of Hopwood Park Motorway Service Area, UK
One of the main barriers to implementing SUDS is concern about performance and maintenance costs since there are few well-documented case-studies. This paper summarizes studies conducted between 2000 and 2008 of the performance and maintenance of four SUDS management trains constructed in 1999 at the Hopwood Park Motorway Service Area, central England. Assessments were made of the wildlife value and sedimentation in the SUDS ponds, the hydraulic performance of the coach park management train, water quality in all management trains, and soil/sediment composition in the grass filter strip, interceptor and ponds. Maintenance procedures and costs were also reviewed. Results demonstrate the benefits of a management train approach over individual SUDS units for flow attenuation, water treatment, spillage containment and maintenance. Peak flows, pond sediment depth and contaminant concentrations in sediment and water decreased through the coach park management train. Of the 2007 annual landscape budget of £15,000 for the whole site, the maintenance costs for SUDS only accounted for £2,500 compared to £4,000 for conventional drainage structures. Furthermore, since sediment has been attenuated in the management trains, the cost of sediment removal after the recommended period of three years was only £554 and, if the design is not compromised, less frequent removal will be required in future
The Expanded Very Large Array
In almost 30 years of operation, the Very Large Array (VLA) has proved to be
a remarkably flexible and productive radio telescope. However, the basic
capabilities of the VLA have changed little since it was designed. A major
expansion utilizing modern technology is currently underway to improve the
capabilities of the VLA by at least an order of magnitude in both sensitivity
and in frequency coverage. The primary elements of the Expanded Very Large
Array (EVLA) project include new or upgraded receivers for continuous frequency
coverage from 1 to 50 GHz, new local oscillator, intermediate frequency, and
wide bandwidth data transmission systems to carry signals with 16 GHz total
bandwidth from each antenna, and a new digital correlator with the capability
to process this bandwidth with an unprecedented number of frequency channels
for an imaging array. Also included are a new monitor and control system and
new software that will provide telescope ease of use. Scheduled for completion
in 2012, the EVLA will provide the world research community with a flexible,
powerful, general-purpose telescope to address current and future astronomical
issues.Comment: Added journal reference: published in Proceedings of the IEEE,
Special Issue on Advances in Radio Astronomy, August 2009, vol. 97, No. 8,
1448-1462 Six figures, one tabl
Radio Observations of SN 1980K: Evidence for Rapid Presupernova Evolution
New observations of SN 1980K made with the VLA at 20 and 6 cm from 1994 April
through 1996 October show that the supernova (SN) has undergone a significant
change in its radio emission evolution, dropping by a factor of ~2 below the
flux density S \propto t^{-0.73} power-law decline with time t observed
earlier. However, although S at all observed frequencies has decreased
significantly, its current spectral index of \alpha= -0.42\pm0.15 (S \propto
\nu^{+\alpha}) is consistent with the previous spectral index of
\alpha=-0.60_{-0.07}^{+0.04}.
It is suggested that this decrease in emission may be due to the SN shock
entering a new region of the circumstellar material which has a lower density
than that expected for a constant speed (w), constant mass-loss rate (Mdot)
wind from the progenitor. If such an interpretation is correct, the difference
in wind and shock speeds appears to indicate a significant evolution in the
mass-loss history of the SN progenitor ~10^4 years before explosion, with a
change in circumstellar density (\propto Mdot/w) occurring over a time span of
\lesssim 4 kyr. Such features could be explained in terms of a fast
``blue-loop'' evolutionary phase of a relatively massive pre-SN progenitor
star. If so, we may, for the first time, provide a stringent constraint on the
mass of the SN progenitor based solely on the SN's radio emission.Comment: 22 pages, 3 figures, to appear in Ap
Long-term follow-up of residual masses after chemotherapy in patients with non-seminomatous germ cell tumours
This retrospective study was undertaken to determine the outcome of patients with non-seminomatous germ cell tumour who achieved a serological complete response but who had residual radiologic abnormalities upon completion of primary platinum-based chemotherapy. This was an analysis of 76 consecutive patients treated at Mount Vernon Hospital between 1983 and 1997. The patients were placed into two groups based upon whether they had surgical resection (surgery group, 48 patients) or observation (observation group, 28 patients) of residual radiologic masses on completion of initial chemotherapy (to enter the surgery group, complete surgical resection must have been achieved). The primary end-points were progression-free and overall survival. The percentage of patients alive with median follow-up 66 months was 90% for the surgery group and 80% for the observation group (P= 0.53, not significant). The percentage of patients continuously disease-free was 70% in the surgery group and 80% in the observation group (P= 0.31, not significant). In the small sub-group of patients with differentiated teratoma (TD) in the primary lesion who were observed, there was no excess risk of relapse or death. Patients who achieve a serological complete response after primary chemotherapy, but are left with ≤ 2 cm radiological masses that are not cystic and have responded, can be safely observed with diligent follow-up. © 2000 Cancer ResearchCampaig
A Case Study on Artefact-based RE Improvement in Practice
Most requirements engineering (RE) process improvement approaches are
solution-driven and activity-based. They focus on the assessment of the RE of a
company against an external norm of best practices. A consequence is that
practitioners often have to rely on an improvement approach that skips a
profound problem analysis and that results in an RE approach that might be
alien to the organisational needs. In recent years, we have developed an RE
improvement approach (called \emph{ArtREPI}) that guides a holistic RE
improvement against individual goals of a company putting primary attention to
the quality of the artefacts. In this paper, we aim at exploring ArtREPI's
benefits and limitations. We contribute an industrial evaluation of ArtREPI by
relying on a case study research. Our results suggest that ArtREPI is
well-suited for the establishment of an RE that reflects a specific
organisational culture but to some extent at the cost of efficiency resulting
from intensive discussions on a terminology that suits all involved
stakeholders. Our results reveal first benefits and limitations, but we can
also conclude the need of longitudinal and independent investigations for which
we herewith lay the foundation
Chandra Observation of the Globular Cluster NGC 6440 and the Nature of Cluster X-ray Luminosity Functions
As part of our campaign to determine the nature of the various source
populations of the low-luminosity globular cluster X-ray sources, we have
obtained a Chandra X-ray Observatory ACIS-S3 image of the globular cluster NGC
6440. We detect 24 sources to a limiting luminosity of ~2 times 10^31 erg/s
(0.5-2.5keV) inside the cluster's half-mass radius, all of which lie within ~2
core radii of the cluster center. We also find excess emission in and around
the core which could be due to unresolved point sources. Based upon X-ray
luminosities and colors, we conclude that there are 4-5 likely quiescent
low-mass X-ray binaries and that most of the other sources are cataclysmic
variables. We compare these results to Chandra results from other globular
clusters and find the X-ray luminosity functions differ among the clusters.Comment: 9 pages, 4 figures, accepted by ApJ, minor changes, added table of
clusters' physical parameter
Transgenic camelina oil is an effective source of eicosapentaenoic acid and docosahexaenoic acid in diets for farmed rainbow trout, in terms of growth, tissue fatty acid content, and fillet sensory properties
The oilseed Camelina sativa was genetically engineered to produce eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) at levels similar to fish oil (FO), which we tested as a lipid source in diets for rainbow trout. Three experimental diets were tested, a FO control, a low‐level transgenic camelina oil (LCO) diet (no FO with 12.5 g/kg camelina), and a high‐level transgenic camelina oil (HCO) diet (no FO with 130 g/kg transgenic camelina). Trout (initial weight 49.8 ± 11 g/fish) were fed for 12 weeks and were evaluated for growth performance, fatty acid content (muscle, liver, brain, and eye), and sensory properties of fillets. The final lengths and weights of fish fed LCO and HCO diets were higher compared to fish fed FO. There were no differences in weight gain, condition factor, specific growth rate, feed intake, and feed conversion ratio. EPA in muscle tissue was higher in fish fed HCO and FO diets compared to the LCO diet. Compound‐specific stable isotope analysis revealed that rainbow trout fed the FO diet stored isotopically enriched DHA compared to the lighter DHA in fish fed HCO. Trout fillets from the HCO treatment were firmer in texture and had a higher orange intensity compared to the FO group
The clinical effectiveness and cost-effectiveness of cetuximab (mono- or combination chemotherapy), bevacizumab (combination with non-oxaliplatin chemotherapy) and panitumumab (monotherapy) for the treatment of metastatic colorectal cancer after first-line chemotherapy (review of technology appraisal No.150 and part review of technology appraisal No. 118): a systematic review and economic model
Colorectal cancer is the third most commonly diagnosed cancer in the UK after breast and lung cancer. People with metastatic disease who are sufficiently fit are usually treated with active chemotherapy as first- or second-line therapy. Recently, targeted agents have become available including anti-epidermal growth factor receptor (EGFR) agents, for example cetuximab and panitumumab, and anti-vascular endothelial growth factor (VEGF) receptor agents, for example bevacizumab
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