156 research outputs found
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Measured Water Temperature Characteristics in a Pipeline Distribution System
YesThis paper describes the design, development, deployment and performance assessment of a
prototype system for monitoring the 'health' of a water distribution network based on the
temperature distribution and time-dependent variations in temperature across the network. It
has been found that the water temperature can reveal unusual events in a water distribution
network, indicated by dynamic variations in spatial temperature differential. Based on this
indication it is shown how patterns of changes in the water temperature can be analysed using
AQUIS pipeline distribution software and used in conjunction with hydraulic (e.g. flow and
pressure) sensors to indicate the state of ÂżhealthÂż of the network during operation
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Artificial Neural Network Model for a Low Cost Failure Sensor: Performance Assessment in Pipeline Distribution
YesThis paper describes an automated event detection and
location system for water distribution pipelines which is based upon
low-cost sensor technology and signature analysis by an Artificial
Neural Network (ANN). The development of a low cost failure
sensor which measures the opacity or cloudiness of the local water
flow has been designed, developed and validated, and an ANN based
system is then described which uses time series data produced by
sensors to construct an empirical model for time series prediction and
classification of events. These two components have been installed,
tested and verified in an experimental site in a UK water distribution
system. Verification of the system has been achieved from a series of
simulated burst trials which have provided real data sets. It is
concluded that the system has potential in water distribution network
management
Recent developments in scholarly publishing to improve research practices in the life sciences
This is the author accepted manuscript. The final version is available from Portland Press via the DOI in this record.We outline recent developments in scholarly publishing that we think will improve the working environment and career prospects for life scientists. Most prominently, we discuss two key developments. (1) Life scientists are now embracing a preprint culture leading to rapid dissemination of research findings. (2) We outline steps to overcome the reproducibility crisis. We also briefly describe other innovations in scholarly publishing, along with changes to open access mandates from funding agencies.John Templeton Foundatio
Modelling both the continual erosion and regeneration of discolouration material in drinking water distribution systems
The erosion of the cohesive layers of particulate matter that causes discolouration in water
distribution system mains has previously been modelled using the Prediction of Discolouration in
Distribution Systems (PODDS) model. When first proposed, PODDS featured an unvalidated
means by which material regeneration on pipe walls could be simulated. Field and laboratory studies
of material regeneration have yielded data that suggest that the PODDS formulations incorrectly
model these processes.
A new model is proposed to overcome this shortcoming. It tracks the relative amount of
discolouration material that is bound to the pipe wall over time at each of a number of shear
strengths. The model formulations and a mass transport model have been encoded as software,
which has been used to verify the modelâs constructs and undertake sensitivity analyses. The new
formulations for regeneration are conceptually consistent with field and laboratory observed data
and has potential value in the proactive management of water distribution systems, such as
evaluating change in discolouration risk and planning timely interventions
Comparing and contrasting threat assessments of plant species at the global and sub-global level
Evidence-based assessments of extinction risk are established tools used to inform the conservation of plant species, and form the basis of key targets within the framework of the Global Strategy for Plant Conservation (GSPC). An overall picture of plants threat assessments is challenging due to the use of a variety of methodologies and range in scope from global to subnational. In this study, we quantify the state of progress in assessing the extinction risk of all land plants, determine the key geographic and taxonomic gaps with respect to our understanding of plant extinction risk, and evaluate the impact of different sources and methodologies on the utility of plant assessments. To this end, we have analyzed a cleaned dataset compiled from IUCN Red List of Threatened Species and Regional Red Lists. We reveal that there are assessments available for 89,810 distinct species or 25% of all accepted land plant species. However unlike with other major organismal lineages the bulk of the plant species assessments are derived from Regional Red Lists, and not the Global IUCN Red List. We demonstrate that this bias towards regional assessments results in distinct taxonomic and geographic strengths and weaknesses, and we identify substantial taxonomic and geographic gaps in the assessment coverage. With species that have been assessed in common at both global and regional levels, we explore the implications of combining threat assessments from different sources. We find that half of global and regional assessments do not agree on the exact category of extinction risk for a species. Regional assessments assign a higher risk of extinction; or underestimate extinction risk with almost equal frequency. We conclude with recommended interventions, but support the suggestion that all threat assessments should be pooled to provide more data and broaden the scope of threat assessments for monitoring progress towards GSPC targets
Magnetic Impurities in the Pnictide Superconductor BaKFeAs
NMR measurements have been performed on single crystals of
BaKFeAs (x = 0, 0.45) and CaFeAs grown from Sn
flux. The Ba-based pnictide crystals contain significant amounts of Sn in their
structure, %, giving rise to magnetic impurity effects evident in the
NMR spectrum and in the magnetization. Our experiments show that the large
impurity magnetization is broadly distributed on a microscopic scale,
generating substantial magnetic field gradients. There is a concomitant 20%
reduction in the transition temperature which is most likely due to magnetic
electron scattering. We suggest that the relative robustness of
superconductivity () in the presence of severe magnetic inhomogeneity
might be accounted for by strong spatial correlations between impurities on the
coherence length scale.Comment: 14 pages, 6 figures (submitted to New Journal of Physics
Estimating lung cancer risk from chest x-ray and symptoms: a prospective cohort study
Background Chest X-ray (CXR) is the first-line investigation for lung cancer in many countries but previous research has suggested that the disease is not detected by CXR in approximately 20% of patients. The risk of lung cancer, with particular symptoms, following a negative CXR is not known.
Aim To establish the sensitivity and specificity of CXR requested by patients who are symptomatic; determine the positive predictive values (PPVs) of each presenting symptom of lung cancer following a negative CXR; and determine whether symptoms associated with lung cancer are different in those who had a positive CXR result compared with those who had a negative CXR result.
Design and setting A prospective cohort study was conducted in Leeds, UK, based on routinely collected data from a service that allowed patients with symptoms of lung cancer to request CXR.
Method Symptom data were combined with a diagnostic category (positive or negative) for each CXR, and the sensitivity and specificity of CXR for lung cancer were calculated. The PPV of lung cancer associated with each symptom or combination of symptoms was estimated for those patients with a negative CXR.
Results In total, 114 (1.3%) of 8996 patients who requested a CXR were diagnosed with lung cancer within 1 year. Sensitivity was 75.4% and specificity was 90.2%. The PPV of all symptoms for a diagnosis of lung cancer within 1 year of CXR was <1% for all individual symptoms except for haemoptysis, which had a PPV of 2.9%. PPVs for a diagnosis of lung cancer within 2 years of CXR was <1.5% for all single symptoms except for haemoptysis, which had a PPV of 3.9%.
Conclusion CXR has limited sensitivity; however, in a population with a low prevalence of lung cancer, its high specificity and negative predictive value means that lung cancer is very unlikely to be present following a negative result. Findings also support guidance that unexplained haemoptysis warrants urgent referral, regardless of CXR result
Automated Data-Driven Approaches to Evaluating and Interpreting Water Quality Time Series Data from Water Distribution Systems
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