159 research outputs found
Capillary Heterogeneity in Sandstone Rocks During CO2/Water Core-flooding Experiments
AbstractWe have successfully applied a novel experimental technique to measure drainage capillary pressure curves in reservoir rocks with representative reservoir fluids at high temperatures and pressures. The method consists of carrying out 100% CO2 flooding experiments at increasingly higher flow rates on a core that is initially saturated with water and requires that the wetting-phase pressure is continuous across the outlet face of the sample. Experiments have been carried out on a Berea Sandstone core at 25 and 50°C and at 9MPa pore pressure, while keeping the confining pressure at 12MPa. Measurements are in good agreement with data from mercury intrusion porosimetry. The technique possesses a great potential of applicability due to the following reasons: (a) it can be applied in conjunction with steady-state relative permeability measurements, as it shares a very similar experimental configuration; (b) it is faster than traditional (porous-plate) techniques used for measuring capillary pressure on rock cores with reservoir fluids; (c) by comparison with results from mercury porosimetry, it allows for the estimation of the interfacial and wetting properties of the CO2/water system, the latter being unknown for most rocks; (d) by combination with X-ray CT scanning, the method allows for the observation of capillary pressure–saturation relationships on mm-scale subsets of the rock core. The latter are of high relevance as they directly and non- destructively measure capillary pressure curve heterogeneity in sandstone rocks
Microplastic accumulation in endorheic river basins: – The example of the Okavango Panhandle (Botswana)
The Okavango Panhandle is themain influent watercourse of the Okavango Delta, an inland sink of the entire sediment
load of the Cubango-Okavango River Basin (CORB). The sources of pollution in the CORB, and other endorheic basins,
are largely understudied when compared to exorheic systems and the world's oceans. We present the first study of the
distribution of microplastic (MP) pollution in surface sediments of the Okavango Panhandle in Northern Botswana. MP
concentrations (64 μm-5 mm size range) in sediment samples from the Panhandle range between 56.7 and 399.5 particles
kg−1 (dry weight) when analysed with fluorescence microscopy. The concentrations ofMP in the 20 μm to 5mm
grain size range (analysed with Raman spectroscopy) range between 1075.7 and 1756.3 particles kg−1. One shallow
core (15 cm long) from an oxbow lake suggests that MP size decreases with depth while MP concentration increases
downcore. Raman Spectroscopy revealed that the compositions of the MP are dominated by polyethene terephthalate
(PET), polypropylene (PP), polyethene (PE), polystyrene (PS), and polyvinyl chloride (PVC). Fromthis novel data set it
was possible to estimate that 10.9–336.2 billion particles could be transported into the Okavango Delta annually, indicating
that the region represents a significant sink for MP, raising concerns for the unique wetland ecosystem
DARE: A Reflective Platform Designed to Enable Agile Data-Driven Research on the Cloud
The DARE platform has been designed to help research developers deliver user-facing applications and solutions over diverse underlying e-infrastructures, data and computational contexts. The platform is Cloud-ready, and relies on the exposure of APIs, which are suitable for raising the abstraction level and hiding complexity. At its core, the platform implements the cataloguing and execution of fine-grained and Python-based dispel4py workflows as services. Reflection is achieved via a logical knowledge base, comprising multiple internal catalogues, registries and semantics, while it supports persistent and pervasive data provenance. This paper presents design and implementation aspects of the DARE platform, as well as it provides directions for future development.PublishedSan Diego (CA, USA)3IT. Calcolo scientific
Against academic identity
‘Academic identity’ is a key issue for debates about the professionalisation of university teaching and research, as well as the meaning and purpose of higher education. However, the concept of ‘academic identity’ is not adequate to the critical task for which it is utilised as it fails to deal with the real nature of work in capitalist society. It is important to move on from the mystifying and reified politics of identity and seek to understand academic life so that its alienated forms can be transformed. This can be done by grasping the essential aspects of capitalist work in both its abstract and concrete forms, as well as the historical and social processes out of which academic labour has emerged
DARE: A Reflective Platform Designed to Enable Agile Data-Driven Research on the Cloud
The DARE platform has been designed to help research developers deliver user-facing applications and solutions over diverse underlying e-infrastructures, data and computational contexts. The platform is Cloud-ready, and relies on the exposure of APIs, which are suitable for raising the abstraction level and hiding complexity. At its core, the platform implements the cataloguing and execution of fine-grained and Python-based dispel4py workflows as services. Reflection is achieved via a logical knowledge base, comprising multiple internal catalogues, registries and semantics, while it supports persistent and pervasive data provenance. This paper presents design and implementation aspects of the DARE platform, as well as it provides directions for future development.PublishedSan Diego (CA, USA)3IT. Calcolo scientific
Using low-cost sensor technologies and advanced computational methods to improve dose estimations in health panel studies: results of the AIRLESS project.
BACKGROUND: Air pollution epidemiology has primarily relied on fixed outdoor air quality monitoring networks and static populations. METHODS: Taking advantage of recent advancements in sensor technologies and computational techniques, this paper presents a novel methodological approach that improves dose estimations of multiple air pollutants in large-scale health studies. We show the results of an intensive field campaign that measured personal exposures to gaseous pollutants and particulate matter of a health panel of 251 participants residing in urban and peri-urban Beijing with 60 personal air quality monitors (PAMs). Outdoor air pollution measurements were collected in monitoring stations close to the participants' residential addresses. Based on parameters collected with the PAMs, we developed an advanced computational model that automatically classified time-activity-location patterns of each individual during daily life at high spatial and temporal resolution. RESULTS: Applying this methodological approach in two established cohorts, we found substantial differences between doses estimated from outdoor and personal air quality measurements. The PAM measurements also significantly reduced the correlation between pollutant species often observed in static outdoor measurements, reducing confounding effects. CONCLUSIONS: Future work will utilise these improved dose estimations to investigate the underlying mechanisms of air pollution on cardio-pulmonary health outcomes using detailed medical biomarkers in a way that has not been possible before.This project is funded under the Newton Fund Programme awarded by Natural Environmental Research Council (NERC Grant NE/N007018/1) with support from Medical Research Council (MRC) and by the National Natural Science Foundation of China (NSFC Grant 81571130100). The NSFC funding is mainly used to support the field work in China, and NERC funding is mainly used for coordination and the further analysis
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