The relevance of microbial processes in geo-energy applications

The subsurface is a vast reservoir which we exploit in various ways. We extract energy in the form of oil/gas or heat from it. We use it for the storage of energy, e.g., in shallow geothermal applications or for the underground storage of natural gas. A lot of recent research has studied the potential for storing hydrogen (H2) in the subsurface. We also use the subsurface to dispose of energy-related waste, e.g., radioactive materials, carbon dioxide (CO2), and acid gas.For a long time, the subsurface was considered sterile below a few metres, probably stemming from work carried out in the 1950s which suggested that bacteria in Pacific sediments most likely disappeared somewhere just below 8m (Morita and ZoBell, 1955). This observation seems to have been extrapolated to the subsurface in general, but over time, as methods developed and microbiologists probed harder, this view changed, and it is now recognised that microbial communities exist at depths where the subsurface is exploited for most types of geo-energy. This raises questions about what sort of microbial community exists, how active it is, what limits and drives that activity and how this might impact geo-energy operations.Cited as: Ebigbo, A., Gregory, S. P. The relevance of microbial processes in geo-energy applications. Advances in Geo-Energy Research, 2021, 5(1): 5-7, doi: 10.46690/ager.2021.01.0

Pore-scale modelling of biofilm activity in the underground storage of hydrogen

The storage of hydrogen in the subsurface to compensate fluctuations in energy demand and supply is considered an important part of future energy strategies. It has been observed that, within the period of storage, there is a partial conversion of hydrogen in the presence of carbon dioxide to methane. This has been attributed to the activity of microorganisms (archaea and bacteria) indigenous to the storage site. The talk will look at pore-scale phenomena including the interplay of different microbes (methanogens, acetogens, and acetotrophs) within a biofilm at the gas—water interface, the growth and decay of the multi-species biofilm, and the diffusion, consumption, and production of the dissolved gases. A numerical model with interface tracking, based on a volume-of-fluid method, is proposed for investigating these effects. The aim of the study is the description and quantification of the dominant processes which determine the amount of biomass such a reservoir can support and the rate at which the microorganisms produce methane as a contribution to explaining the observed field-scale phenomenon

Role of artificial intelligence in diagnosing Barrett’s esophagus-related neoplasia

Barrett’s esophagus is associated with an increased risk of adenocarcinoma. Thorough screening during endoscopic surveillance is crucial to improve patient prognosis. Detecting and characterizing dysplastic or neoplastic Barrett’s esophagus during routine endoscopy are challenging, even for expert endoscopists. Artificial intelligence-based clinical decision support systems have been developed to provide additional assistance to physicians performing diagnostic and therapeutic gastrointestinal endoscopy. In this article, we review the current role of artificial intelligence in the management of Barrett’s esophagus and elaborate on potential artificial intelligence in the future

Synchrotron-based pore-network modeling of two-phase flow in Nubian Sandstone and implications for capillary trapping of carbon dioxide

Depleted oil fields in the Gulf of Suez (Egypt) can serve as geothermal reservoirs for power generation using a CO2-Plume Geothermal (CPG) system, while geologically sequestering CO2. This entails the injection of a substantial amount of CO2 into the highly permeable brine-saturated Nubian Sandstone. Numerical models of two-phase flow processes are indispensable for predicting the CO2-plume migration at a representative geological scale. Such models require reliable constitutive relationships, including relative permeability and capillary pressure curves. In this study, quasi-static pore-network modelling has been used to simulate the equilibrium positions of fluid-fluid interfaces, and thus determine the capillary pressure and relative permeability curves. Three-dimensional images with a voxel size of 0.65 micro m3 of a Nubian Sandstone rock sample have been obtained using Synchrotron Radiation X-ray Tomographic Microscopy. From the images, topological properties of pores/throats were constructed. Using a pore-network model, we performed a sequential primary drainage-main imbibition cycle of quasi-static invasion in order to quantify (1) the CO2 and brine relative permeability curves, (2) the effect of initial wetting-phase saturation (i.e. the saturation at the point of reversal from drainage to imbibition) on the residual-trapping potential, and (3) study the relative permeability-saturation hysteresis. The results improve our understanding of the potential magnitude of capillary trapping in Nubian Sandstone, essential for future field-scale simulations. Further, an initial basin-scale assessment of CO2 storage capacity, which incorporates capillary trapping, yields a range of 14-49 GtCO2 in Nubian Sandstone, Gulf of Suez Basin

Artificial intelligence in the management of barrett’s esophagus and early esophageal adenocarcinoma

Esophageal adenocarcinoma is increasing in incidence and is the most common subtype of esophageal cancer in Western societies. The stepwise progression of Barrett´s metaplasia to high-grade dysplasia and invasive adenocarcinoma provides an opportunity for screening and surveillance. There are important unresolved issues, which include (i) refining the definition of the screening population in order to avoid unnecessary invasive diagnostics, (ii) a more precise prediction of the (very heterogeneous) individual progression risk from metaplasia to invasive cancer in order to better tailor surveillance recommendations, (iii) improvement of the quality of endoscopy in order to reduce the high miss rate for early neoplastic lesions, and (iv) support for the diagnosis of tumor infiltration depth in order to guide treatment decisions. Artificial intelligence (AI) systems might be useful as a support to better solve the above-mentioned issues

Problem and pro-social behavior among Nigerian children with intellectual disability: the implication for developing policy for school based mental health programs

<p>Abstract</p> <p>Background</p> <p>School based mental health programs are absent in most educational institutions for intellectually disabled children and adolescents in Nigeria and co-morbid behavioral problems often complicate intellectual disability in children and adolescents receiving special education instructions. Little is known about prevalence and pattern of behavioral problems existing co-morbidly among sub-Saharan African children with intellectual disability. This study assessed the prevalence and pattern of behavioral problems among Nigerian children with intellectual disability and also the associated factors.</p> <p>Method</p> <p>Teachers' rated Strengths and Difficulties Questionnaire (SDQ) was used to screen for behavioral problems among children with intellectual disability in a special education facility in south eastern Nigeria. Socio-demographic questionnaire was used to obtain socio-demographic information of the children.</p> <p>Results</p> <p>A total of forty four (44) children with intellectual disability were involved in the study. Twenty one (47.7%) of the children were classified as having behavioral problems in the borderline and abnormal categories on total difficulties clinical scale of SDQ using the cut-off point recommended by Goodman. Mild mental retardation as compared to moderate, severe and profound retardation was associated with highest total difficulties mean score. Males were more likely to exhibit conduct and hyperactivity behavioral problems compared to the females. The inter-clinical scales correlations of teachers' rated SDQ in the studied population also showed good internal consistency (Cronbach Alpha = 0.63).</p> <p>Conclusion</p> <p>Significant behavioral problems occur co-morbidly among Nigerian children with intellectual disability receiving special education instructions and this could impact negatively on educational learning and other areas of functioning. There is an urgent need for establishing school-based mental health program and appropriate screening measure in this environment. These would afford early identification of intellectually disabled children with behavioral problems and appropriate referral for clinical evaluation and interventions. The need to focus policy making attention on hidden burden of intellectual disability in sub-Saharan African children is essential.</p