1,143 research outputs found
Replication Data for: Flow and Transport of Methane from Leaking Underground Pipelines: Effects of Soil Surface Conditions and Implications for Natural Gas Leak Classification
No full textReplication Data for: Jayarathne, J. R. R. N., R. S. Kolodziej, S. N. Riddick, D. J. Zimmerle, and K. M. Smits. 2023. Flow and Transport of Methane from Leaking Underground Pipelines: Effects of Soil Surface Conditions and Implications for Natural Gas Leak Classification. Env. Sci. Tech. Letters, In revie
Dataset associated with "A cautionary report of calculating methane emissions using low-cost fence-line sensors"
No full textA simulated fence-line was constructed at the Colorado State University Methane Emissions Technology Evaluation Center (METEC) site in Fort Collins, CO, USA between the August 27th and September 4th 2020. Four Figaro TGS2611-E00 sensors (Figaro Engineering, Inc.) were deployed with control from a Raspberry Pi and power supplied by solar panels. The sensors were mounted in holes in the bottom of a weather-resistant box and exposed to sample air passing the bottom of the box. Each sensor box also contained a DHT22 temperature and relative humidity sensor (Adafruit Industries). Data presented here were collected by the “Node 1” sensor 30 m away at 45 °N to the emission point, “Node 2” sensor 30 m away at 215 °N to the emission point, “Node 3” sensor 30 m away at 225 °N to the emission point, and “Node 4” sensor 30 m away at 315 °N to the emission point. Methane concentration data were collected every 5 seconds during a natural gas emission of 84 g CH4 h-1 between 2020-08-27 1800 UTC and 2020-08-29 1559 UTC, 167 g CH4 h-1 between 2020-08-29 1600 UTC and 2020-08-31 1559 UTC, and 313 g CH4 h-1 between 2020-08-31 1600 UTC and 2020-09-02 1457 UTC.Methane is emitted during extraction, processing, and transport processes in the natural gas industry. As a powerful greenhouse gas, methane releases are harmful to the environment. Operators aim to minimize methane loss, and continuous monitoring using low-cost fence-line sensors are now being developed to observe methane enhancements downwind of operations. However, it is not clear how useful these systems are and whether they can be used to quantify emissions or simply identify the presence of a leak. To investigate this, we deployed four calibrated low-cost sensors 30 m from emissions of known rates over a 48-hour period. The aims were to determine: 1) how much of the time a fence-line system would detect a leakage event from a single, point source of the size typically seen at oil and gas production well pads; and 2) how accurately a fence-line system can estimate emissions using a relatively simple downwind dispersion method. Our results show that during the 48-hour measurement period the sensors could detect mixing ratios greater than an enhancement threshold of 2 ppm for methane releases of 84 g h-1 40% of the time, 100% of the time for emissions of 167 g h-1 and 100% of the time downwind of the 313 g h-1. We show that emissions can be overestimated by as much as 4 x 10102 times using a simple Gaussian plume equation, which was attributed to the inability of the equation to parameterize lateral dispersion at distances less than 100 m. Using two other methods, near real-time average emissions can be calculated to be within 23% of a known emission rate of the source, however individual emissions can vary by -100% and +1,885%. This study provides evidence to support the use of low-cost sensors as autonomous fence-line monitoring systems to detect and potentially quantify emissions. If the sensors are properly calibrated and sensor deployment location is optimized for prevailing wind directions at each site, fence-line systems could be used routinely to quantify emissions from oil and gas infrastructure.This work was funded by the METEC Industry Advisory Board (IAB) at Colorado State University
John Stuart Mill’s projected science of society: 1827-1848
No full textThe purpose of the thesis is to examine John Stuart Mill’s political thought from
about 1827 to 1848 as an exercise in intellectual history. It focuses, first, on Mill’s view,
formulated by the late 1830s, that contemporary society was ‘civilized’, and second, on
his project of a science of society, which he aspired to develop in the late 1830s and
early 1840s.
By the late 1830s, Mill came to the view that his contemporary society was a
‘commercial society or civilization’, dominated by the middle, commercial class. The
first part of my thesis, constituted by Chapters 2-4, discusses the way in which Mill
formed his notion of civilization, and what he meant by the term ‘civilization’. Mill paid
attention to the implications of the rise of the middle class, and regarded such
phenomena of contemporary society as the corruption of the commercial spirit and
excessive social conformity as an inevitable consequence of the rise of the middle class.
The second part of the thesis, constituted by Chapters 5-9, examines Mill’s
projected science of society. In the late 1830s and early 1840s, Mill attempted to
develop a new science of society whose subject-matter was the nature and prospects of
commercial, civilized society. This aspiration culminated in A System of Logic,
published in 1843. In examining Mill’s projected science, I pay particular attention to
the fact that he conceived new sciences of history and of the formation of character,
both of which were indispensable in his project, although he failed to give a complete
account of these sciences. My thesis shows that the implications of his interest both in
history and in the formation of character are more significant than Mill scholars have
assumed
Methane emissions from oil and gas platforms in the North Sea.
No full textDownload the README.txt file for a detailed description of this dataset's contentSince 1850 the concentration of atmospheric methane (CH4), a potent greenhouse gas, has more than doubled. Recent studies suggest that emission inventories may be missing sources and underestimating emissions. To investigate whether offshore oil and gas platforms leak CH4 during normal operation, we measured CH4 mole fractions around eight oil and gas production platforms in the North Sea which were neither flaring gas nor off-loading oil. We use the measurements from summer 2017, along with meteorological data, in a Gaussian plume model to estimate CH4 emissions from each platform. We find CH4 mole fractions of between 11 and 370 ppb above background concentrations downwind of the platforms measured, corresponding to a median CH4 emission of 6.8 g CH4 s-1 for each platform, with a range of 2.9 to 22.3 g CH4 s-1. When matched to production records, during our measurements individual platforms lost between 0.04% and 1.4% of gas produced with a median loss of 0.23%. When the measured platforms are considered collectively, (i.e. the sum of platforms’ emission fluxes weighted by the sum of the platforms’ production), we estimate the CH4 loss to be 0.19% of gas production. These estimates are substantially higher than the emissions most recently reported to the National Atmospheric Emission Inventory (NAEI) for total CH4 loss from United Kingdom platforms in the North Sea. The NAEI reports CH4 losses from the offshore oil and gas platforms we measured to be 0.13% of gas production, with most of their emissions coming from gas flaring and offshore oil loading, neither of which were taking place at the time of our measurements. All oil and gas platforms we observed were found to leak CH4 during normal operation and much of this leakage has not been included in UK emission inventories. Further research is required to accurately determine total CH4 leakage from all offshore oil and gas operations and to properly include the leakage in national and international emission inventories
Corrigendum: Pneumococcal vaccine impacts on the population genomics of non-typeable haemophilus influenzae: (Microbial Genomics 2021; 9, 10.1099/mgen.0.000209)
No full textThere was a change in the author names in the published article. The new list should read: David W. Cleary1,2, Vanessa T. Devine3, Denise E. Morris1, Karen L. Osman1, Rebecca A. Gladstone4, Stephen D. Bentley4, Saul N. Faust1,5, Stuart C. Clarke1,2,6 1Faculty of Medicine and Institute for Life Sciences, University of Southampton, Southampton, UK. 2NIHR Southampton Biomedical Research Centre, University Hospital Southampton Foundation NHS Trust, Southampton, UK. 3Northern Ireland Centre for Stratified Medicine and Clinical Translational Research Innovation Centre, Londonderry, UK. 4Pathogen Genomics, Wellcome Trust Sanger Institute, UK. 5NIHR Southampton Clinical Research Facility, University Hospital Southampton Foundation NHS Trust, Southampton, UK. 6Global Health Research Institute, University of Southampton, Southampton, UK.</p
Advance Australia fair [music] /
No full textNew ed. For chorus (SATB); Issued as a postcard.; "Commonwealth anthem and patriotic song".; "Performed by the massed bands at the Naming of the Federal Capital Celebrations, Canberra".; "The author of this song ... is indebted to the late Professor Stuart Blackie, of Edinburgh for improvement in last verse".; 3rd verse begins: 'Beneath our radiant Southern Cross ...'; Also available online http://nla.gov.au/nla.mus-an6397900; MUS: N, A, N/A, B, C, JAF.Advance Australia fair. Chorus scor
Electromagnetic control of an oscillating turbulent jet in a confined cavity
No full textControl of self-sustained jet oscillations in confined cavities is of importance for many industrial applications. It has been shown that the mechanism underlying these oscillations consists of three stages: (i) growth of the oscillation, (ii) amplitude limitation and (iii) delayed destruction of the recirculation zone bounding the jet. It has also been shown that oscillations may be enhanced or suppressed by applying (e.g. electromagnetic) body forces. In the current paper we study the influence of electromagnetic forces oriented aligned with or opposite to the direction of the jet on the oscillation mechanism. The influence of the forcing is found to depend on the Stuart number N in relation to a critical Stuart number Ncrit. We demonstrate that for |N| < Ncrit , the oscillation mechanism is essentially unaltered, with moderate modifications in the jet oscillation amplitude and frequency compared to N=0N=0. For N > Ncrit, electromagnetic forcing leads to total suppression of the self-sustained oscillations. For N < Ncrit , electromagnetic forces dominate over inertia and lead to strongly enhanced oscillations, which for N≪−NcritN≪−Ncrit become irregular. As was earlier demonstrated for N=0,N=0, the present paper shows that for −6Ncrit<N<Ncrit−6Ncrit<N<Ncrit the oscillatory behaviour, i.e. frequencies, oscillation amplitudes and wave shapes, can be described quantitatively with a zero-dimensional model of the delay differential equation (DDE) type, with model constants that can be a priori determined from the Reynolds and Stuart number and geometric ratios.Accepted Author ManuscriptChemE/Transport PhenomenaFluid Mechanic
DNA fusion gene vaccination mobilizes effective anti-leukemic cytotoxic T lymphocytes from a tolerized repertoire
No full textThe majority of known human tumor-associated antigens derive from non-mutated self proteins. T cell tolerance, essential to prevent autoimmunity, must therefore be cautiously circumvented to generate cytotoxic T cell responses against these targets. Our strategy uses DNA fusion vaccines to activate high levels of peptide-specific CTL. Key foreign sequences from tetanus toxin activate tolerance-breaking CD4+ T cell help. Candidate MHC class Ibinding tumor peptide sequences are fused to the C terminus for optimal processing and presentation. To model performance against a leukemia-associated antigen in a tolerized setting, we constructed a fusion vaccine encoding an immunodominant CTL epitopederived from Friend murine leukemia virus gag protein (FMuLVgag) and vaccinated tolerant FMuLVgag-transgenic (gag-Tg) mice. Vaccination with the construct induced epitopespecificIFN-c-producing CD8+ T cells in normal and gag-Tg mice. The frequency and avidity of activated cells were reduced in gag-Tg mice, and no autoimmune injury resulted. However, these CD8+ T cells did exhibit gag-specific cytotoxicity in vitro and in vivo. Also, epitope-specific CTL killed FBL-3 leukemia cells expressing endogenous FMuLVgag antigen and protected against leukemia challenge in vivo. These results demonstrate a simple strategy to engage anti-microbial T cell help to activate epitope-specific polyclonal CD8+ T cell responses from a residual tolerized repertoire
Quantifying Methane Emission Rates Using Downwind Measurements
No full textThis entry describes the methods used to quantify methane emissions from either point or area sources using downwind methods. The methods described could be used as a practical guide to quantify emissions of any trace gas type from either a point or area emission source. Methane is a relatively strong greenhouse gas, its GWP is 25 times larger than CO2 over a 100-year period, and an increase in methane anthropogenic emissions has been correlated to a changing global climate. Emission estimates that are calculated and used for national inventories are usually derived from bottom-up approaches, however there is now an increasing pressure for these to be validated by direct measurement. Calculating emission rates from downwind measurements has proven to be a versatile and relatively simple approach for direct measurement. Downwind measurement method descriptions are presented here as a practicable guide to quantifying point and area source emissions. Emission quantification is a two-stage process where methane concentration and meteorological data must be measured downwind of a source and then converted to emissions using an atmospheric dispersion model. Only four technology types currently measure in the range typical of downwind methane concentrations: metal oxide sensors, non-dispersive infrared sensors, tunable diode laser absorption spectrometers and optical cavity instruments. The choice of methane measurement is typically determined by the size of the emission source, location and the budget of the project. Meteorological data are essential to quantifying emissions, especially regarding wind speed and direction. In most cases, simple atmospheric dispersion approaches can be used to quantify both area and point emissions using these downwind measurements. Emissions can be generated using limited data (only methane concentration, wind speed, wind direction, and locations are necessary), but quantification uncertainty can be reduced using more input data. Site selection and location of instrument deployment are essential because quantification approaches assume a flat fetch (no aerodynamic obstructions) and constant wind fields. When modeling assumptions are violated, quantification uncertainty can range between +250% and −100% of the actual emission rate. At present there, is no happy medium between modeling complexity and computational time, and this remains the biggest challenge for downwind emission quantification
Author Impact Metrics in Communication Sciences and Disorder Research
No full text
Purpose
The purpose was to examine author-level impact metrics for faculty in the communication sciences and disorder research field across a variety of databases.
Method
Author-level impact metrics were collected for faculty from 257 accredited universities in the United States and Canada. Three databases (i.e., Google Scholar, ResearchGate, and Scopus) were utilized.
Results
Faculty expertise was in audiology (24.4%;
n
= 490) and speech-language pathology (75.6%;
n
= 1,520). Women comprised 68.1% of faculty, and men comprised 31.9% of faculty. The percentage of faculty in the field of communication sciences and disorders identified in each database was 10.5% (
n
= 212), 44.0% (
n
= 885), and 84.4% (
n
= 1,696) for Google Scholar, ResearchGate, and Scopus, respectively. In general, author-level impact metrics were positively skewed. Metric values increased significantly with increasing academic rank (
p
< .05), were greater for men versus women (
p
< .05), and were greater for those in audiology versus speech-language pathology (
p
< .05). There were statistically significant positive correlations between all author-level metrics (
p
< .01).
Conclusions
These author-level metrics may serve as a benchmark for scholarly production of those in the field of communication sciences and disorders and may assist with professional identity management, tenure and promotion review, grant applications, and employment.
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