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This article reassesses the concept of a house from a non-human perspective. The two worlds that collide in this article are philosophical analyses that are “beyond the human” and sustainable engineering house design. By analyzing the houses of ten animal species for shelter/skin properties, life pedagogy (how to live), materials and resources, thermal dynamics, and structural elements, we speculate on the future of housing. The premise of this article is that “beyond the human” philosophy opens a new visage to comprehend and conceptualize what a house could be. Beyond the human theorizing is defined by philosophy that has gone beyond framing an exploration internally to the benefit of themselves, as human subject(s). This article speculates that considering animal house construction is a way forward for thought in a changing climate.

This study explores the fundamental, molecular- to microscopic-level behavior of methane gas confined into nanoporous silica proxies with different pore diameters and surface-to-volume (S/V) ratios. Surfaces and pore walls of nanoporous silica matrices are decorated with hydroxyl (-OH) groups, resembling natural heterogeneity. High-pressure MAS NMR was utilized to characterize the interactions between methane and the engineered nanoporous silica proxies under various temperature and pressure regimes. There was a change in the chemical shift position of confined methane slightly in the mixtures with nanoporous silica up to 393 K, as shown by high-pressure

Modern cities produce areas of poverty, despite their overall wealth. These pockets of living can exacerbate societal problems, especially because the opposite end of the societal spectrum is often close by. This paper examines an educational initiative in one such district, called Claymore, in the suburbs of outer Sydney. The project deployed a mobile youth van equipped with high-tech educational hardware and software, and encouraged local youth to take advantage of the van, to further high-tech skills acquisition. This paper offers a Deleuze/Guattari (1988) cartographic approach to mapping the effects of the van extracted from their opus maxima, 1000 Plateaus. This approach is a mode of social topology that deepens the type of discourse analysis that one may take from Foucault and its uses in educational research (e.g., Ball, 2012). The social cartography that one might derive from Deleuze/Guattari involves producing a ‘plane of immanence’ and assemblages about the phenomena under scrutiny, in the case of this article, the mobile van initiative in Claymore. This does not mean that hierarchies are diminished, but that they are reset for the purposes of analysis, so that their complex relationships are realized and understood. This paper looks to describe and analyse what is immanent to the situation in Claymore, and what effects the mobile van might have given this state of affairs.

Geological carbon dioxide sequestration in deep saline aquifers can play a key role in the successful mitigation of greenhouse gas emissions. Several conditions have been identified that affect the solubility of CO2 in water, including temperature, pressure, pH, and salinity. At similar conditions, the solubility in bulk fluids differs from the solubility in confined porous media. We conducted equilibrium molecular dynamics (MD) simulations to investigate the solubility of CO2 in water confined in slit-shaped calcite pores. We studied the effects of brine (NaCl and MgCl2). Compared to bulk water/brine, the solubility of CO2 is lower in calcite pores and decreases as the pores narrow. Adsorption energy calculations were performed to compare our results to CO2 solubility in water-filled silica pores. These results indicate that narrower calcite pores are less attractive for the adsorption of CO2. In addition, the simulation results suggest that the difference in the positions where the ions adsorb also affects whether salts increase or decrease the solubility of CO2 in confined water. Confinement and ions also reduce the mobility of CO2 in water. These observations contribute to the design of long-term CO2 sequestration strategies as they provide boundary constraints for the amount of CO2 that can dissolve in hydrated pores, as well as the timing of CO2 transport in such systems.

The fundamental properties of the neutron make it a powerful tool for Earth science investigations because neutrons provide information that cannot be obtained by any other research method. This is because neutrons are magnetically sensitive, nondestructive, and sensitive to the lighter elements, such as hydrogen. They provide a unique, nondestructive method for obtaining information ranging from Ångstrom-scale atomic structures (and related motions) to micron-scale material strain, stress, and texture, and even up to meso-scale porous matrices and defects in materials and functional components. In this article, we introduce neutrons and their unique properties, neutron production and sources, and provide an overview of the different types of neutron methods applicable to the Earth sciences.

Neutron scattering is a powerful tool to elucidate the structure and dynamics of systems that are important to geochemists, including ion association in complex aqueous solutions, solvent-exchange reactions at mineral–water interfaces, and reaction and transport of fluids in nanoporous materials. This article focusses on three techniques: neutron diffraction, which can reveal the atomic-level structure of aqueous solutions and solids; quasi-elastic neutron scattering, which measures the diffusional dynamics at mineral–water interfaces; and small-angle neutron scattering, which can show how properties of nanoporous systems change during gas, liquid, and solute imbibition and reaction. The usefulness and applicability of the experimental results are extended by rigorous comparison to computational simulations.

In the South Korean film, The Parasite, the underling family, in an act of desperation, uses deceptive means to infiltrate the rich family. The term parasite refers nominally to the underling family, and their efforts to befriend and inhabit the class territory and social hierarchy of the rich family. How can this be of use for education? To answer this, we ask: what can we learn from Parasite to inform contemporary philosophy of education? Primarily, this experimental piece written from different philosophical viewpoints, suggests that the images, narrative, and social context of the film cannot be read stereotypically. Using a blend of Deleuze and Stiegler ‘cinema-theory’, we present a heuristic perspective on the Parasite from three viewpoints: (1) South Korean society, and how a pedagogy of the parasite helps to understand the dynamics of contemporary philosophy of education in a global context. South Korea is uniquely placed at the cusp and threshold of deterritorializing Western capitalism, given its position next to the only in-tact communist state system; (2) The film shows how theorizing an exceptional notion of time contributes to the overall pedagogy of the parasite. Here, being a parasite is about waiting to attach oneself to a host, yet this waiting is an anxious, perceptive, adherent time, a reciprocal time, and one internally interconnected to that of the host; (3) The ethics of the parasite. The parasite chooses a host from a certain viewpoint before attaching itself and trying to be absorbed into the host. The pedagogy of the parasite suggests a unique ethical treatment of these assimilative processes and allows us to consider cinema as a parasitic means to shake the passive audience out of its stupor when bearing witness to the violence in the film and its own collusion in the trauma and reality of contemporary capitalism.

This philosophy of education paper describes a schizophrenic situation. A new airport is being planned in the locale of a university which is a Centre of Excellence of Education for Sustainable Dev...

Weathering plays a crucial role in a number of environmental processes, and the microstructure and evolution of multi-scale pore space is a critically important factor in weathering. In igneous rocks the infiltration of meteoric water into initially relatively dry material can initiate disaggregation, increasing porosity and surface area, and allowing further disaggregation and weathering. These processes, in turn, allow biota to colonize the rock, further enhancing the weathering rate. In some rocks this may be driven by primary mineral oxidation. One such mineral, biotite, has been repeatedly mentioned as a cause of cracking during oxidation. However, the scale-dependence of the processes by which this occurs are poorly understood. We cannot, therefore, accurately extrapolate laboratory reaction rates to the field in predictive numerical models. In order to better understand the effects of oxidation and test the hypothesis that fracture and disaggregation are initiated by swelling of oxidizing biotites, we reacted granite cores in a selenic acid-rich aqueous solution at 200 °C for up to 438 days. Elevated temperatures and selenic acid were used to provide relatively fast reaction rates and highly oxidizing conditions in sealed reaction vessels. These experiments were analyzed using a combination of imaging, X-ray diffraction, Mossbauer spectroscopy, and small- and ultra-small angle neutron scattering to interrogate porosity and microfracture formation. The experimental results show little observable biotite swelling, but significantly more observable fractures and growth of iron oxides and/or clays along grain boundaries. Pyrite disappeared from the reacted sample. Significant increases in porosity were also observed at the sample rim, likely associated with feldspar alteration. Fractures and transport were observed throughout the core, suggesting that stresses due to crystallization pressures caused by the growing iron phases may be the initiating factors in granite weathering, possibly followed by biotite swelling after sufficient permeability is achieved.

Understanding the wetting properties of reservoir rocks can be of great benefit for advanced applications such as the effective trapping and geological storage of CO2. Despite their importance, not all mechanisms responsible for wetting mineral surfaces in subsurface environments are well understood. Factors such as temperature, pressure and salinity are often studied, achieving results with little unanimity; other possible factors are left somewhat unexplored. One such factor is the effect of contamination. In the present study, the effects of adding a non-aqueous organic contaminant, ethanol, on the CO2–water interfacial tension (IFT) and the CO2/water/calcite contact angle were investigated using molecular dynamics simulations. Within the conditions studied, relatively small amounts of ethanol cause a significant decrease in the CO2–water IFTs, as well as a pronounced increase in the water-calcite-CO2 three phase contact angle. The latter result is due to the decrease of the IFT between CO2 and water and the strong adsorption of ethanol on the solid substrate. These findings could be helpful for explaining how impurities can affect experimental data and could lead to effective carbon sequestration strategies.

This paper draws on the social ecology of Felix Guattari, to suggest that young children learn in complex social and natural situations, in this case ‘getting muddy’. The notion of social ecology w...

In this contribution, the relaxation and diffusional behaviors of low viscous fluids, water and methanol confined into mesoporous silica and controlled size pore glass were investigated. The engineered porous systems are relevant to geologically important subsurface energy materials. The engineered porous proxies were characterized by Brunauer–Emmett–Teller (BET) surface analyzer, nuclear magnetic resonance (NMR) spectroscopy, and electron microscopy (EM) to determine surface area, pore-wall protonation and morphology of these materials, respectively. The confined behavior of the low viscous fluids was studied by varying pore diameter, fluid-to-solid ratio, temperature, and pressure, and then compared to bulk liquid state. Both relaxation and diffusion behaviors for the confined fluids showed increasing deviation from pure bulk fluids as the fluid-to-solid ratio was decreased, and surface-to-volume ratio (S/V) was varied. Variable pressure deuteron NMR relaxation of confined D2O and confined methanol, deuterated at the hydroxyl or methyl positions, were performed to exploit the sensitivity of the deuteron quadrupole moment to molecular rotation. The methanol results demonstrated greater pressure dependence than those for water only in bulk. The deviations from bulk liquid behavior arise from different reasons such as confinement and the interactions between confined fluid and the nano-pore wall. The results of the present report give insight into the behavior of low viscosity fluid in nano-confined geometries under different state conditions.

The dynamics of water on or in a mineral substrate plays an important role in interfacial processes. This is because the structure and dynamics of interfacial water deviate from those of bulk water...

Various aspects of electrospun fibers prepared from terpolymer of tetrafluoroethylene (TFE), hexafluoropropylene (HFP), and vinylidene fluoride (VDF) (THV)/acetone solutions at two applied voltages, THV/acetone solutions having Texas montmorillonite with two ratios, and THV/ethyl acetate solutions using two needle sizes are described. Fibers from THV/acetone and THV/ethyl acetate solutions showed shallow indentations and pores, respectively. The clay, functioning as electrospinning agent, did not influence the fiber morphology, but yielded narrower fiber diameter distribution and the thinnest fibers. Heterogeneous fiber diameter distribution and increase in the fiber diameters were observed by lowering the voltage for fibers of THV/acetone solutions. Fibers from THV/ethyl acetate solutions had the largest diameter and the broadest diameter distribution. Electrospun THV fibers having both hydrophobic characteristics with nearly 140° water contact angles and oleophilic properties with oil contact angles less than 45° might have applications in areas such as water/oil separation.

Adsorption of fluids in nanoporous materials is important for a variety of industries including catalysis and is a promising strategy for hydrogen storage and CO2 sequestration. It has therefore been studied extensively. In a typical adsorption experiment, the sorbent sample is usually in powder form which consists of several crystallites separated by an inter-crystalline space. This inter-crystalline space may compete with the nanopores in engineered as well as natural materials for fluid adsorption. While in computer simulations that are used to complement experiments, much attention is focused on the choice of force-field parameters, the effect of inter-crystalline spaces on the properties of adsorbed fluids remains largely ignored. We attempt to study the effects of inter-crystalline space on the simulated adsorption of ethane and CO2 modelled in TraPPE formalism in a silicalite model composed of crystallites separated by different inter-crystalline spaces. The effect of inter-crystalline space is found to be profound and differs for the two sorbates. Presence of quadrupole moment makes CO2 adsorption in the inter-crystalline space more favorable and suggests that increasing surface area of a catalytic substrate for enhanced adsorption might be a relatively more effective strategy for adsorption of a quadrupolar molecule as compared to an apolar molecule. Also, the results imply that in experiments investigating molecules confined in porous media using powder samples, apolar molecules are less likely to give undesired bulk-like contribution from inter-crystalline spaces to the experimental data. CO2 molecules adsorbed on the crystallite surfaces are found to exhibit a high degree of orientational ordering and exhibit a preferred orientation favorable for higher amounts of adsorption. While larger inter-crystalline spacings lead to higher adsorption, the effect of using a larger crystallite is to reduce the amount of adsorption. The mutual negation of these two effects explains the apparent agreement of the experimental data obtained on a powder sample and the simulation data obtained using a perfect crystal model. This work has implications for both simulations of adsorption isotherms in nanoporous materials and the interpretation of experimental data obtained for these systems.

Mg-MOF-74 is a metal-organic framework (MOF) that exhibits a high capacity for CO$_2$ adsorption. Given the importance of CO$_2$ confinement in Mg-MOF-74 for capture and storage applications, it is important to understand the structural and dynamical behavior of CO$_2$ in Mg-MOF-74 pores. While most molecular simulation studies use ideal single crystal models of nano-porous substrates, the existence of inter-crystalline space has been shown to have profound effects on the sorption, structure and dynamics of the adsorbed fluid. To address these issues, we report a molecular dynamics simulation study at 300 K, of CO$_2$ confined in several models of Mg-MOF-74 with systematically inserted inter-crystalline spacing of different widths. Both structural and dynamical behavior of CO$_2$ is studied in 5 models of Mg-MOF-74, each at 4 different loadings. Six strong sites of CO$_2$ adsorption are found at the periphery of the pores of Mg-MOF-74 in addition to a relatively weak adsorption at the center of the pore. On insertion of inter-crystalline spacing, additional six sites of strong adsorption are seen in the inter-crystalline space close to the pore opening. These additional sites delocalize as the inter-crystalline space is widened and the population of guest molecules adsorbed at the pore center grows at the expense of peripheral population. This redistribution of guest molecules has important implications for their dynamics. While in the model without inter-crystalline space, translation motion is found to be slower at higher loadings, as wider inter-crystalline space is introduced, anomalous loading dependence of translational diffusivity is observed. In general, inserting inter-crystalline spacing is found to enhance both translational as well as rotational motion of the guest molecules. The results reported here provide valuable insight to carbon capture and storage., 15 pages, 9 figures

Understanding the wetting properties of reservoir rocks can be of great benefit for advanced applications such as the effective trapping and geological storage of CO

The philosophy of Gilles Deleuze has become popular in recent moves to embed approaches such as the new materialist and the posthuman in environmental education. Certainly, a newfound respect for the material universe, including the comprehension of the human place in it, and the tendency to a posthuman theoretical position, are both important given the contemporary environmental crisis, named as the Anthropocene. However, this article will argue that both these philosophies do not go far enough. This is because they must retain a political, social and critical edge if they are to be effective, and this edge can be too easily disregarded in the pursuit of increased engagement with the material and everything not human. In contrast, this article will put forward a Deleuzian approach to environmental education, based on the intellectual quadrant of Spinoza-Marx-Nietzsche-Bergson (Figure 1). It will be argued that only by fully connecting these often conflicting and disparate philosophies that a workable new synthesis for environmental education and a cartography for learning can be achieved. The Deleuzian approach to environmental education will be exemplified through an analysis of current environmental practises in schools as assemblage.

Acidification of pore water in geological formations by carbon dioxide (CO2) results in the release of trapped gases, the detection of which can potentially be used to signal leakage of CO2 from storage reservoirs at carbon sequestration sites. In a set of laboratory tests, core materials from a stratigraphic borehole at the proposed FutureGen 2.0 carbon storage site (Jacksonville, IL, USA) were reacted with phosphoric acid to simulate contact with aqueous CO2. Gas released by the reaction was collected and analysed for the composition of the major and noble gases (including isotopes). These experiments yielded several promising tracer candidates for intrinsic monitoring of CO2 leakage at the proposed FutureGen 2.0 site. The most robust signals are the CH4 and 4He released by carbonates in the dolomite and siltstone formations that comprise the proposed primary containment zone. Xenon released from the primary-containment zone also showed promise as a tracer, but a more robust analysis requires a different experimental set up. A general enrichment of CH4, N2 and light noble-gas isotopes with respect to Ar abundance was observed and is consistent with the addition of major gases (CO2, CH4, and to a lesser extent, N2) released by decomposition of carbonate mineral phases and/or organic matter in the dolomite and siltstone formations. No useful signal was obtained from the sandstone formation (representing the proposed injection zone) due to its very low yield of gas when acidified.

It is known that pore confinement affects the structure and transport properties of fluids. It has also been shown that confinement can affect the equilibrium composition of a reactive system. Such...

In the last decade, extensive application of hydraulic fracturing technologies to unconventional low-permeability hydrocarbon-rich formations has significantly increased natural-gas production in the United States and abroad. The injection of surface-sourced fluids to generate fractures in the deep subsurface introduces microbial cells and substrates to low-permeability rock. A subset of injected organic additives has been investigated for their ability to support biological growth in shale microbial community members; however, to date, little is known on how complex xenobiotic organic compounds undergo biotransformations in this deep rock ecosystem. Here, high-resolution chemical, metagenomic, and proteomic analyses reveal that widely-used surfactants are degraded by the shale-associated taxa Halanaerobium, both in situ and under laboratory conditions. These halotolerant bacteria exhibit surfactant substrate specificities, preferring polymeric propoxylated glycols (PPGs) and longer alkyl polyethoxylates (AEOs) over polyethylene glycols (PEGs) and shorter AEOs. Enzymatic transformation occurs through repeated terminal-end polyglycol chain shortening during co-metabolic growth through the methylglyoxal bypass. This work provides the first evidence that shale microorganisms can transform xenobiotic surfactants in fracture fluid formulations, potentially affecting the efficiency of hydrocarbon recovery, and demonstrating an important association between injected substrates and microbial growth in an engineered subsurface ecosystem.

Water-rich fracturing fluids are injected into gas shale formations to promote the effective development of gas. However, the relationship between gas production decreases and the variability flow-back fluid behavior (rate and amount) remains a significant challenge to the industry. This study focused on the effects of water hydration on the rock fracture properties of a major gas shale formation in China. Shale from hydration experiments was characterized for a number of key parameters including length, volume, width, surface area, thickness and fracture frequency. X-ray computed tomography (CT) scanning was conducted on shale reservoir samples exposed to water at zero overburden stress and under three different confining pressures (725 psi, 2175 psi, and 2900 psi). CT scanning images were obtained to evaluate fracture evolutions during hydration for both the connected and unconnected fracture networks. In addition, permeabilities before and after hydration were also quantified. Results from the ambient condition experiment revealed the propagation of fractures, the formation of new fractures, and the formation of better connectivity caused by a more complicated fracture network. However, the fracture evolution of the other three samples under confining pressures are markedly different, including: more unconnected fracture networks, less fracture volume, and a poorer connectivity of fractures.

Using Deleuzian theory for educational research and practice has become an increasingly popular activity (e.g., Cole 2011). However, there are many theoretical complexities to the straightforward application of Deleuze to the educational context. For example, the ‘new materialism’ that Deleuze refers to in the 1960s takes its inspiration from Spinoza, and is an emancipatory (and very human) project. Contrariwise, the ‘new materialism’ of the present moment is frequently applied to educational research and practice specifically as a way out of anthropocentric limits and enclosure. This paper explores the combined forces of humanism and naturalism which are at work in Deleuze’s ‘new materialism’, as type of ‘more-than-human’ emancipation method derived from Bergson and Nietzsche; it is a mode of overcoming human limits, which fully takes into account the connections to and with the non-human world and the ecological consequences of human action. This paper will draw out the specific consequences for educational research and practice in schools of the ‘vitalist-nihilism’ we may derive from Bergson and Nietzsche to analyse matter flows as they enter, mingle with, and exit schools.

The Duke of Edinburgh’s International Award (as it is named in Australia) is an extremely widespread and popular youth development program. Participants (14–25 year olds) navigate the Bronze, Silve...

The Dover 33 Reef, part of the Niagaran Reef Complex in Northern Michigan (USA), has been the focus of an enhanced oil recovery/carbon capture utilization and storage (EOR/CCUS) project as part of the Phase III-Midwest Regional Carbon Sequestration Partnership (Gupta et al., 2013a,b). The Dover 33 structure has experienced significant CO2 flooding in the past two decades, and over the course of the current injection study (between February 2013 and July 2016) has received approximately 100 to 1000 tonnes/day into the central injection well (L-M) 1–33). As part of the geochemical monitoring effort of the study, gas and fluid samples were collected from Dover 33 reef, and several other nearby reef structures, to assess the impact of CO2 injection on the geochemical processes occurring within in the reef. The injected gas is composed of approximately 95% CO2, with a δ13CCO2 of ∼20.5‰, which is consistent with previously published compositions of Antrim shale gas, the source of the CO2. The concentrations and isotopic compositions of higher pressure gas collected from the L-M 5–33 monitoring well were similar to those measured in the injection well, but did exhibit a small but systematic shift in isotopic composition towards lower values over the course of the study, suggesting mixing and dilution between the gas in the reservoir and the injected gas. In contrast the δ13CCO2 of gas samples from the monitoring well with the lower surface pressure, L-M 2–33, are consistently lower throughout the study, ∼18.5‰, indicating that reactions with the injected CO2 are occurring within the reef or with the well casing. Fluid samples were collected to assess the extent of interaction among the injected gas, the reservoir rock, and the brine. The brine samples are acidic (pH ∼ 4.1 to 4.9) with a total salt content of nearly 400 g/L. Analysis of the isotopic composition of dissolved inorganic carbon (DIC) in the Dover 33 brine shows that δ13C is higher than the injected gas (27–33‰) suggesting that the gas is not in equilibrium with DIC in the brine, and that there has been little isotopic exchange with carbonate minerals in the reef. The water isotope composition of the brine, δ18O and δD, plot below the meteoric water line, indicating that the water is not of recent meteoric origin and has undergone isotopic exchange with both gas and minerals within the reef structure. The 87Sr/86Sr ratios of the brine samples range from 0.70865 to 0.70869, consistent with Silurian seawater composition. Geochemical modelling of the brine composition shows that the predicted CO2 solubility as DIC is much greater than the measured DIC, and that the brines are supersaturated with respect to carbonate minerals, suggesting the potential for significant trapping of CO2 in both dissolved and mineral form.

We have investigated the effect of molecular shape and charge asymmetry on the translation dynamics of confined hydrocarbon molecules having different shapes but similar kinetic diameters, inside ZSM-5 pores using molecular dynamics simulations. The mean square displacement of propane, acetonitrile, acetaldehyde, and acetone in ZSM-5 exhibit two different regimes - ballistic and diffusive/sub-diffusive. All the molecules except propane exhibit sub-diffusive motion at time scales greater than 1 ps. The intermediate scattering functions reveal that there is a considerable rotational- translational coupling in the motion of all the molecules, due to the strong geometrical restriction imposed by ZSM-5. Overall the difference in shape and asymmetry in charge imposes severe restriction inside the ZSM-5 channels for all the molecules to different extents. Further, the behavior of molecules confined in ZSM-5 in the present study, quantified wherever possible, is compared to their behavior in bulk or in other porous media reported in literature., 10 Pages, 10 Figures

Adsorption of fluids in nanoporous materials is important for a variety of industries including catalysis and is a promising strategy for hydrogen storage and CO

Fundamental understanding of the subcritical/supercritical behavior of key hydrocarbon species inside nano-porous matrices at elevated pressure and temperature is less developed compared to bulk fluids, but this knowledge is of great importance for chemical and energy engineering industries. This study explores in detail the structure and dynamics of ethane (C(2)H(6)) fluid confined in silica nanopores, with a focus on the effects of pressure and different ratios of C(2)H(6) and CO(2) at non-ambient temperature. Quasi-elastic neutron scattering (QENS) experiments were carried out for the pure C(2)H(6), C(2)H(6):CO(2) = 3:1, and 1:3 mixed fluids confined in 4-nm cylindrical silica pores at three different pressures (30 bars, 65 bars, and 100 bars) at 323 K. Two Lorentzian functions were required to fit the spectra, corresponding to fast and slow translational motions. No localized motions (rotations and vibrations) were detected. Higher pressures resulted in hindrances of the diffusivity of C(2)H(6) molecules in all systems investigated. Pore size was found to be an important factor, i.e., the dynamics of confined C(2)H(6) is more restricted in smaller pores compared to the larger pores used in previous studies. Molecular dynamics simulations were performed to complement the QENS experiment at 65 bars, providing supportive structure information and comparable dynamic information. The simulations indicate that CO(2) molecules are more strongly attracted to the pore surface compared to C(2)H(6). The C(2)H(6) molecules interacting with or near the pore surface form a dense first layer (L1) close to the pore surface and a second less dense layer (L2) extending into the pore center. Both the experiments and simulations revealed the role that CO(2) molecules play in enhancing C(2)H(6) diffusion (“molecular lubrication”) at high CO(2):C(2)H(6) ratios. The energy scales of the two dynamic components, fast and slow, quantified by both techniques, are in very good agreement. Herein, the simulations identified the fast component as the main contributor to the dynamics. Molecule motions in the L2 region are mostly responsible for the dynamics (fast and slow) that can be detected by the instrument.

The wettability behavior of reservoir rocks plays a vital role in determining CO2 storage capacity and containment security. Several experimental studies characterized the wettability of CO2/brine/rock systems for a wide range of realistic conditions. To develop a fundamental understanding of the molecular mechanisms responsible for such observations, the results of molecular dynamics simulations, conducted at atomistic resolution, are reported here for representative systems in a wide range of pressure and temperature conditions. Several force fields are considered, achieving good agreement with experimental data for the structure of interfacial water but only partial agreement in terms of contact angles. In general, the results suggest that, at the conditions chosen, water strongly wet calcite, resulting in water contact angles either too low to be determined accurately with the algorithms implemented here or up to ∼46°, depending on the force field implemented. These values are in agreement with some, but not all experimental data available in the literature, some of which report contact angles as high as 90°. One supercritical CO2 droplet was simulated in proximity of the wet calcite surface. The results show pronounced effects due to salinity, which are also dependent on the force field implemented to describe the solid substrate. When the force field predicts complete water wettability, increasing NaCl salinity seems to slightly increase the calcite affinity for CO2, monotonically as the NaCl concentration increases, because of the preferential adsorption of salt ions at the water–rock interface. When the other force field was implemented, it was not possible to quantify salt effects, but the simulations suggested strong interactions between the supercritical CO2 droplet and the second hydration layer on calcite. The results presented could be relevant for predicting the longevity of CO2 sequestration in geological repositories.

Because gas injection into geological formations is a common technology deployed for enhanced oil recovery (EOR), it is important to understand at the molecular level the relations between competit...

About 60% of natural gas production in the United States comes from hydraulic fracturing of unconventional reservoirs, such as shales or organic-rich micrites. This process inoculates and enriches for halotolerant microorganisms in these reservoirs over time, resulting in a saline ecosystem that includes methane producing archaea. Here, we survey the biogeography of methanogens across unconventional reservoirs, and report that members of genus Methanohalophilus are recovered from every hydraulically fractured unconventional reservoir sampled by metagenomics. We provide the first genomic sequencing of three isolate genomes, as well as two metagenome assembled genomes (MAGs). Utilizing six other previously sequenced isolate genomes and MAGs, we perform comparative analysis of the 11 genomes representing this genus. This genomic investigation revealed distinctions between surface and subsurface derived genomes that are consistent with constraints encountered in each environment. Genotypic differences were also uncovered between isolate genomes recovered from the same well, suggesting niche partitioning among closely related strains. These genomic substrate utilization predictions were then confirmed by physiological investigation. Fine-scale microdiversity was observed in CRISPR-Cas systems of Methanohalophilus, with genomes from geographically distinct unconventional reservoirs sharing spacers targeting the same viral population. These findings have implications for augmentation strategies resulting in enhanced biogenic methane production in hydraulically fractured unconventional reservoirs.