218 research outputs found
The realities of storing carbon dioxide - A response to CO2 storage capacity issues raised by Ehlig-Economides & Economides
In a recent publication, Ehlig-Economides & Economides (2010) have sought to demonstrate that carbon dioxide capture and storage (CCS) is not technically or economically feasible, based on a supposed lack of underground storage capacity. We consider this to be a serious misrepresentation of the scientific, engineering and operational facts surrounding CCS. Ehlig-Economides & Economides raise a number of storage related issues: reservoir boundaries, capacity, pressure management, storage integrity, dissolution and storage in depleted reservoirs. We take each one in turn, highlighting specific errors in the paper but also drawing attention to more general background issues. Finally, we discuss in more detail some inconsistencies in the paper surrounding the reservoir engineering calculations
Developing a comparative marine socio-economic framework for the European Atlantic Area
Availability and easy access to a wide range of natural and human-activity data on the oceans and coastal regions of Europe is the basis for strategic decision-making on coastal and marine policy. Strategies within Europeâs Integrated Maritime Policy, including the Maritime Strategy for the Atlantic Area, Blue Growth, Maritime Spatial Planning and Marine Data and Knowledge, require coherent and comparable socio-economic data across European countries. Similarly, the Marine Strategy Framework Directive requires member states to carry out economic and social analysis of their waters and the reformed Common Fisheries Policy includes a social dimension requiring socio-economic data. However, the availability of consistent, accessible marine socio-economic data for the European Atlantic Arc regions is limited. Ocean economy studies have been undertaken in some countries (for example, Ireland, France, and UK) but timescales and methodologies are not necessarily comparable. Marnet is an EU transnational co-operation project involving eight partners from five member states of the Atlantic Area (Ireland, Spain, UK, France and Portugal). Marnet has developed a methodology to collate comparable marine socio-economic data across the Atlantic regions. The comparative marine socio-economic information system developed by Marnet could provide a template for other European States to follow that could potentially facilitate the construction of a Europe-wide marine economic information system as envisaged under the EU Integrated Maritime Policy
European Science and Technology Network on Unconventional Hydrocarbon Extraction: Annual Report 2015
The present report firstly summarizes the background for creating the "European Science and Technology Network on Unconventional Hydrocarbon Extraction", based on a Communication from the European Commission to the Council and the Parliament. It further describes the organisation and functioning of the Network as well as the status of the foreseen deliverables of the Working Groups realized in 2015.JRC.F.3-Energy Security, Systems and Marke
Two-dimensional hydrodynamic lattice-gas simulations of binary immiscible and ternary amphiphilic fluid flow through porous media
The behaviour of two dimensional binary and ternary amphiphilic fluids under
flow conditions is investigated using a hydrodynamic lattice gas model. After
the validation of the model in simple cases (Poiseuille flow, Darcy's law for
single component fluids), attention is focussed on the properties of binary
immiscible fluids in porous media. An extension of Darcy's law which explicitly
admits a viscous coupling between the fluids is verified, and evidence of
capillary effects are described. The influence of a third component, namely
surfactant, is studied in the same context. Invasion simulations have also been
performed. The effect of the applied force on the invasion process is reported.
As the forcing level increases, the invasion process becomes faster and the
residual oil saturation decreases. The introduction of surfactant in the
invading phase during imbibition produces new phenomena, including
emulsification and micellisation. At very low fluid forcing levels, this leads
to the production of a low-resistance gel, which then slows down the progress
of the invading fluid. At long times (beyond the water percolation threshold),
the concentration of remaining oil within the porous medium is lowered by the
action of surfactant, thus enhancing oil recovery. On the other hand, the
introduction of surfactant in the invading phase during drainage simulations
slows down the invasion process -- the invading fluid takes a more tortuous
path to invade the porous medium -- and reduces the oil recovery (the residual
oil saturation increases).Comment: 48 pages, 26 figures. Phys. Rev. E (in press
Blue Growth: A Transitions Approach to Developing Sustainable Pathways
The sustainable management of Blue Growth is an urgent issue for coastal states. Marine industries have rapidly expanded over the last two decades and this is projected to continue with the European Green Deal and post-COVID economic recovery policies. The intensification of Blue Growth could have adverse socio-ecological implications and must, therefore, be managed in terms of sustainability, natural resource boundaries, and coastal community well-being. Managing Blue Growth in a sustainable manner however, is challenging due to the longstanding inefficiencies and inertia of existing marine governance regimes. Adopting a transitions approach has been advanced as a way of steering regime change so that it is not inhibited by these persistent problems. This paper reports on four case studies that adopt transitions thinking and use the multi-level perspective as a broad analytical framework through which to understand institutional dynamics, drivers and responses within core marine sectors. Our case studies analysis reveals several significant pressures for regime change within key marine sectors. These pressures need to be addressed through the adoption of a transition management approach. By adopting this approach and engaging key stakeholders, national and EU marine governance authorities can develop sustainable Blue Growth pathways that minimize the impact of continued growth on communities and the marine environment, maximizing the implementation of sustainable practices and addressing issues such as biodiversity loss and climate change
Magnitude, impact, and stability of primary headache subtypes: 30 year prospective Swiss cohort study
Objective To determine the prevalence, impact, and stability of different subtypes of headache in a 30 year prospective follow-up study of a general population sample
Three dimensional hysdrodynamic lattice-gas simulations of binary immiscible and ternary amphiphilic flow through porous media
We report the results of a study of multiphase flow in porous media. A
Darcy's law for steady multiphase flow was investigated for both binary and
ternary amphiphilic flow. Linear flux-forcing relationships satisfying Onsager
reciprocity were shown to be a good approximation of the simulation data. The
dependence of the relative permeability coefficients on water saturation was
investigated and showed good qualitative agreement with experimental data.
Non-steady state invasion flows were investigated, with particular interest in
the asymptotic residual oil saturation. The addition of surfactant to the
invasive fluid was shown to significantly reduce the residual oil saturation.Comment: To appear in Phys. Rev.
Challenges in measuring indicators of progress for the Atlantic Action Plan
The EU Atlantic Action Plan (AAP) has recently been updated and revised to support âblue growthâ along Europeâs western coastal regions. The revisions reflect recent challenges facing the Atlantic Arc maritime economies including the Covid-19 crisis, Brexit and the new requirements of the European Green Deal. This new revision, termed AAP 2.0, also addresses some of the weaknesses highlighted in the original Atlantic Action Plan particularly regarding identifying indicators that may be used to measure progress in the achievement of the Planâs objectives. Using a database with comparable marine socio-economic data across the Atlantic regions, a number of indicators are identified that may be used to monitor progress of the AAP 2.0. Recent trends and spatial distributions across the Atlantic Arc region are shown for these indicators. The challenges in measuring progress are also highlighted, including where some AAP objectives and associated indicators may conflict with other EU policy aims and where the current monitoring framework can be bolstered with the inclusion of new indicators
Geoelectrical characterization of carbonate and silicate porous media in the presence of supercritical CO 2
This article has been accepted for publication in Geophysical Journal International ©: 2015 The authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.The relative permittivity (Δr) and the electrical conductivity (Ï) of porous media are known to be functions of water saturation (S). As such, their measurements can be useful in effective characterisations and monitoring of geological carbon sequestration using geoelectrical measurement techniques. In this work, the effects of pressure, temperature and salt concentration on bulk ΔrâS and ÏâS relationships were investigated for carbonate (limestone) and silicate porous media (both unconsolidated domains) under dynamic and quasi-static supercritical CO2 (scCO2)-brine/water flow. In the silica sand sample, the bulk Δr (Δb) for scCO2âwater decreases as the temperature increases. On the contrary, slight increase was seen in the Δb with temperature in the carbonate sample for the scCO2-water system. These trends are more conspicuous at high water saturation. The ΔbâS curves for the scCO2âwater flow in the silica sand also show clear dependency on the domain pressure, where Δb increases as the domain pressure increases. Furthermore, the bulk Ï (Ïb), at any particular saturation for the scCO2-brine system rises as the temperature increases with more significant increase found at very high water saturation. Both Δb and Ïb values are found to be greater in the limestone than silica sand porous samples for similar porosity values. Based on different injection rates investigated, we do not find significant dynamic effects in the ΔbâS and ÏbâS relationships for the scCO2-brine/water system. As such, geoelectrical characteristics can be taken as reliable in the monitoring of two-phase flow system in the porous media. It can be inferred from the results that the geoelectrical techniques are highly dependent on water saturation. This dependence is more conspicuous at higher water saturation. Different mathematical models examined show their reliability at different water saturation ranges. The polynomial fit developed in this work takes into consideration the fluid pressure in the system as well as the initial bulk relative permittivity prior to the injection of CO2. The polynomial fit shows a good reliability in the prediction of the geo-electrical properties of the CO2âwaterâporous media system, especially at higher water saturation. In comparison, the mixing model from the literature shows more reliability in the prediction of similar property at lower water saturation
Transtorno autĂstico e doença celĂaca : sem evidĂȘncias de associação
Objective: To evaluate the possible association between celiac disease (CD) and/or gluten sensitivity (GS) and autism spectrum disorder
(ASD). Methods: Occurrences of CD were determined in a group of children and adolescents affected by ASD and, conversely, occurrences
of ASD were assessed in a group of biopsy-proven celiac patients. To detect the possible existence of GS, the levels of antigliadin antibodies in ASD patients were assessed and compared with the levels in a group of non-celiac children. Results: The prevalence of CD or GS in
ASD patients was not greater than in groups originating from the same geographical area. Similarly the prevalence of ASD was not greater
than in a group of biopsy-proven CD patients. Conclusion: No statistically demonstrable association was found between CD or GS and ASD.
Consequently, routine screening for CD or GS in all patients with ASD is, at this moment, neither justifed nor cost-effective. ___________________________________________________________________________________ RESUMOObjetivo: Avaliar a possĂvel associação entre doença celĂaca (DC) e/ou sensibilidade ao glĂșten (SG) e transtorno do espectro autista (TEA).
MĂ©todos: OcorrĂȘncias de DC foram determinadas em um grupo de crianças e adolescentes afetados pelo TEA e a ocorrĂȘncia d TEA foi
avaliada em um grupo de pacientes com DC comprovada por biĂłpsia. Para detectar a possĂvel existĂȘncia de SG, foram determinados nĂveis
de anticorpos antigliadina em pacientes com TEA e comparados ao grupo de crianças sem a doença celĂaca. Resultados: A prevalĂȘncia de
DC ou SG nĂŁo foi maior no grupo de pacientes com TEA quando comparada a grupos de indivĂduos originĂĄrios da mesma regiĂŁo geogrĂĄfca.
De modo similar, a prevalĂȘncia do TEA nĂŁo foi maior ao ser comparada ao grupo de pacientes com DC. ConclusĂŁo: NĂŁo houve associação
estatisticamente demonstråvel entre DC ou SG e TEA. Consequentemente, não são justifcåveis, no momento, exames de rotina para detecção de DC ou SG em pacientes com TEA
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