405 research outputs found
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Trace gas transport in the subsurface of Mars
The ExoMars Trace Gas Orbiter (TGO) will have the capability of detecting and characterizing a broad suite of trace gases in the atmosphere of Mars. Interpreting the results of this mission will require an understanding of how these trace gases are transported from their sources, which may be deep underground, to the atmosphere. Here we present results of modeling designed to measure the timescales of release from putative subsurface methane sources. These transport timescales are far longer than mixing times in the atmosphere and could be up to 10 million years
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The Beagle 2 environmental sensors: intended measurements and scientific goals
The Beagle 2 lander, due for arrival on Mars in December 2003, carries an Environmental Sensors Suite to monitor the local meteorology and carry out simple dust and oxidant measurements. The suite is described, and the scientific goals are discussed
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Investigating TriHaloMethanes with respect to humidity
The disinfection of potable water has dramatically reduced the instances of Cholera and similar ailments within a population drawing upon that water source. There is however the possibility that Natural Organic Matter (NOM) can interact with the disinfection compounds to form Disinfection By-Products (DBP). One group of DBPs are Trihalomethanes (THMs) with several compounds of the group being suspected carcinogens. Within the UK the total concentration of all THMs within drinking water must not exceed 100”g/l.
At present water authorities take samples of the water supply and return them to a central laboratory for analysis. This provides an accurate test but one which can involve a long lead time in discovering a potential hazard to public health.
A Field Asymmetric Ion Mobility Spectrometer (FAIMS) sensor may be ideally placed to perform in situ continuous monitoring at particular sites. As part of a PhD co-sponsored by The Open University and Owlstone Nanotech Plc an investigation is ongoing to discover how sensitive a FAIMS device is with respect to THMs and humidity when sampling. Initial results and the method of data processing, which involves peak fitting to evolving spectra are presented
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Quantification of ethyl acetate using FAIMS
The enjoyment of wine is based not only on its flavour but also its aroma. The presence of compounds, such as ethyl acetate, can add a desirable depth of body, richness and sweetness to a wine. However, if the levels exceed the human perception threshold (100 - 200 mg/l) an aroma similar to acetone becomes prevalent and the wine is regarded as spoilt.A study was undertaken to determine the concentration of ethyl acetate within wine using a Gas Chromatograph coupled with Field Asymmetric Ion Mobility Spectrometry (FAIMS).
The use of FAIMS (also known as Differential Mobility Spectrometry) as a selective detector has increasingly become prevalent within analytical science. There is now a vibrant community of researchers working with the technique and different commercial systems are readily available. Two such systems are the Tourist and Lonestar instruments available from Owlstone Ltd. The Owlstone systems are characterised by the sensor being a solid state device, which imposes constraints on operational parameters but also offers opportunities over comparable devices.
FAIMS technology requires the interaction of compounds both within the ionisation and separation region. To influence the interactions in these two regions studies were completed at elevated (compared to ambient) pressures and humidity. The study of ethyl acetate within wine provided an opportunity to investigate these effects and also provided a route for optimisation of the instrument for the study.
It was found, in contrast to a previously reported investigation, that increasing the pressure resulted in a greater resolution of compounds. A more complicated relationship was observed with respect to humidity, believed attributable to water being an important constituent of reactive and product ion formation. Additional effects due to the presence of co-solvents were observed and subsequently managed so as to provide increased sensitivity.
The quantification of ethyl acetate within wine was accomplished considerably below the human perception threshold providing the opportunity to better manage this multifarious compound throughout manufacture and the product lifecycle
Lessons learned from the introduction of autonomous monitoring to the EUVE science operations center
The University of California at Berkeley's (UCB) Center for Extreme Ultraviolet Astrophysics (CEA), in conjunction with NASA's Ames Research Center (ARC), has implemented an autonomous monitoring system in the Extreme Ultraviolet Explorer (EUVE) science operations center (ESOC). The implementation was driven by a need to reduce operations costs and has allowed the ESOC to move from continuous, three-shift, human-tended monitoring of the science payload to a one-shift operation in which the off shifts are monitored by an autonomous anomaly detection system. This system includes Eworks, an artificial intelligence (AI) payload telemetry monitoring package based on RTworks, and Epage, an automatic paging system to notify ESOC personnel of detected anomalies. In this age of shrinking NASA budgets, the lessons learned on the EUVE project are useful to other NASA missions looking for ways to reduce their operations budgets. The process of knowledge capture, from the payload controllers for implementation in an expert system, is directly applicable to any mission considering a transition to autonomous monitoring in their control center. The collaboration with ARC demonstrates how a project with limited programming resources can expand the breadth of its goals without incurring the high cost of hiring additional, dedicated programmers. This dispersal of expertise across NASA centers allows future missions to easily access experts for collaborative efforts of their own. Even the criterion used to choose an expert system has widespread impacts on the implementation, including the completion time and the final cost. In this paper we discuss, from inception to completion, the areas where our experiences in moving from three shifts to one shift may offer insights for other NASA missions
Negotiating queer and religious identities in higher education: queering âprogressionâ in the âuniversity experienceâ
This article addresses the negotiation of âqueer religiousâ student identities in UK higher education. The âuniversity experienceâ has generally been characterised as a period of intense transformation and self-exploration, with complex and overlapping personal and social influences significantly shaping educational spaces, subjects and subjectivities. Engaging with ideas about progressive tolerance and becoming, often contrasted against âbackwardsâ religious homophobia as a sentiment/space/subject âoutsideâ education, this article follows the experiences and expectations of queer Christian students. In asking whether notions of âqueering higher educationâ (Rumens 2014 Rumens, N. 2014. âQueer Business: Towards Queering the Purpose of the Business School.â In The Entrepreneurial University: Public Engagements, Intersecting Impacts, edited by Y. Taylor, 82â104. Basingstoke: Palgrave Macmillan.) âfitâ with queer-identifying religious youth, the article explores how educational experiences are narrated and made sense of as âprogressiveâ. Educational transitions allow (some) sexual-religious subjects to negotiate identities more freely, albeit with ongoing constraints. Yet perceptions of what, where and who is deemed âprogressiveâ and âbackwardsâ with regard to sexuality and religion need to be met with caution, where the âuniversity experienceâ can shape and shake sexual-religious identity
Utilizing image texture to detect land-cover change in Mediterranean coastal wetlands
Land-use/cover change dynamics were investigated in a Mediterranean coastal wetland. Change Vector Analysis (CVA) without and with image texture derived from the co-occurrence matrix and variogram were evaluated for detecting land-use/cover change. Three Landsat Thematic Mapper (TM) scenes recorded on July 1985, 1993 and 2005 were used, minimizing change detection error caused by seasonal differences. Images were geometrically, atmospherically and radiometrically corrected. CVA without and with texture measures were implemented and assessed using reference images generated by object-based supervised classification. These outputs were used for cross-classification to determine the âfromâtoâ change used to compare between techniques. The Landsat TM image bands together with the variogram yielded the most accurate change detection results, with Kappa statistics of 0.7619 and 0.7637 for the 1985â1993 and 1993â2005 image pairs, respectively
âI just think itâs dirty and lazyâ: Fat surveillance and erotic capital
Contextualised within the UK mediascape, this article discusses how fat signifies the classed failures of neoliberalism. Because class aspiration, entrepreneurialism and the myth of the competitive individual are pivotal to the political economy of neoliberalism, fat is increasingly and vehemently vilified as abject across media platforms. Fat-surveillance media, which are marketed specifically to women by their visuals, gendered community, language, and structures of feeling, participate in a âgynaeopticonâ where the controlling gaze is female, and the many women regulate the many women. Rather than being a top-down form of governance and discipline such as in the panopticon, control is affectively devolved among systems or networks of the policing gaze. As well as monitoring women along the lines of class, I argue that these media circumscribe the de-individualising possibilities and passions of the libido
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