Influence of micro-particles on gas hydrate formation kinetics: Potential application to methane storage and transportation

Methane hydration is a safe, stable and environmentally friendly technology to bind and utilize excess coalbed methane gas. However, a limiting factor of the commercial application of coalbed methane hydration technology is the sluggish hydration reaction kinetics of methane hydrate formation, which needs to be improved. In this work, different micro-particle suspensions are prepared from an initial solution containing gellan gum and L-tryptophan, along with varying mass fractions of NiMnGa, Cu and carboxylated multi-walled carbon nanotubes, and their influence on the reaction kinetics in methane hydrate formation is examined. The results show that the formation of methane hydrate is enhanced by these micro-particles to varying degrees. Micro-particles show a synergistic solubilization effect with L-tryptophan and gellan gum at 6.2 MPa. The induction times of 1 wt.% NiMnGa system and 1 wt.% Cu system are the shortest. The 2 wt.% NiMnGa system has a pronounced impact on methane gas consumption, and the average gas consumption rates of the 0.1 wt.% Cu system and 1 wt.% NiMnGa system are faster. However, as the concentration of Cu micro-particles increases, both gas consumption and the average generation rate exhibits a linear decrease. This work offers valuable recommendations for choosing the experimental settings, micro-particle types and concentrations. We also lay the groundwork for the practical and sustainable application of coalbed methane storage and transportation technology employing the hydrate approach.Document Type: Original articleCited as: Wu, Q., Tang, T., Zhao, Z., Li, L., Elhefnawey, M., Zhang, B. Influence of micro-particles on gas hydrate formation kinetics: Potential application to methane storage and transportation. Advances in Geo-Energy Research, 2023, 10(3): 189-199. https://doi.org/10.46690/ager.2023.12.0

ALTA: a simple nutritional prognostic score for patients with hepatitis B virus-related acute-on-chronic liver failure

BackgroundMalnutrition, despite being a common complication, is often neglected in patients with hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF). The objective of this study was to develop a simplified nutritional prognostic score to accurately predict mortality in HBV-ACLF patients.MethodsIn this multicenter retrospective study, clinical data from 530 HBV-ACLF patients were used to create a new prognostic score, which was then validated in two external cohorts (n = 229 and 248).ResultsFour independent factors were significantly associated with 28-day mortality in HBV-ACLF patients, forming a novel prognostic score (ALTA score = 0.187 × age—0.849 × lymphocyte count—2.033 × total cholesterol—0.148 × albumin—0.971). Notably, the AUROC of ALTA score for 28/90-day mortality (0.950/0.967) were significantly higher than those of three other ACLF prognostic scores (COSSH-ACLF II, 0.864/0.734; MELD, 0.525/0.488; MELD-Na, 0.546/0.517; all P < 0.001), and three known nutritional scores (CONUT, 0.739/0.861; OPNI, 0.279/0.157; NRS-2002, 0.322/0.286; all P < 0.001). The prediction error rates of ALTA score for 28-day mortality were significantly lower than COSSH-ACLF II (7.3%), MELD (14.4%), MELD-Na (12.7%), CONUT (9.0%), OPNI (30.6%), and NRS2002 (34.1%) scores. Further classifying ALTA score into two strata, the hazard ratios of mortality at 28/90 days were notably increased in the high-risk groups compared to the low-risk group (15.959 and 5.740). These results were then validated in two external cohorts.ConclusionALTA, as a simplified nutritional prognostic score for HBV-ACLF, demonstrates superiority over the COSSH-ACLF II and other scores in predicting short-term mortality among HBV-ACLF patients. Therefore, it may be used to guide clinical management, particularly in primary care settings

Inferring plant–plant interactions using remote sensing

Rapid technological advancements and increasing data availability have improved the capacity to monitor and evaluate Earth's ecology via remote sensing. However, remote sensing is notoriously ‘blind’ to fine-scale ecological processes such as interactions among plants, which encompass a central topic in ecology. Here, we discuss how remote sensing technologies can help infer plant–plant interactions and their roles in shaping plant-based systems at individual, community and landscape levels. At each of these levels, we outline the key attributes of ecosystems that emerge as a product of plant–plant interactions and could possibly be detected by remote sensing data. We review the theoretical bases, approaches and prospects of how inference of plant–plant interactions can be assessed remotely. At the individual level, we illustrate how close-range remote sensing tools can help to infer plant–plant interactions, especially in experimental settings. At the community level, we use forests to illustrate how remotely sensed community structure can be used to infer dominant interactions as a fundamental force in shaping plant communities. At the landscape level, we highlight how remotely sensed attributes of vegetation states and spatial vegetation patterns can be used to assess the role of local plant–plant interactions in shaping landscape ecological systems. Synthesis. Remote sensing extends the domain of plant ecology to broader and finer spatial scales, assisting to scale ecological patterns and search for generic rules. Robust remote sensing approaches are likely to extend our understanding of how plant–plant interactions shape ecological processes across scales—from individuals to landscapes. Combining these approaches with theories, models, experiments, data-driven approaches and data analysis algorithms will firmly embed remote sensing techniques into ecological context and open new pathways to better understand biotic interactions

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Wrinkling of a polymeric gel during transient swelling

When exposed to an external solvent, a dry polymeric network imbibes the solvent and undergoes large deformation. The resulting aggregate is known as a hydrogel. This swelling process is diffusion driven and thus results in differential swelling during transient swelling. When subjected to external geometrical constraints, such as being rigidly fixed or attachment to a compliant substrate, wrinkles have been shown to appear due to mechanical instabilities. In the case of free swelling, there are no external constraints to induce the instabilities accounting for wrinkling patterns. However, during the transient swelling process, the swelling differential between the gel on the exterior and the interior causes compressive stresses and gives rise to mechanical instabilities. It is also observed that the time dependence of the swelling profile causes the wrinkles to evolve with time. In this work, we investigate this interesting phenomenon of transient wrinkle mode evolution using the finite element and state-space methods. From our simulations and prediction, we find that there is an inverse relation between critical wave number and time, which has earlier been observed in experiments

Asymmetric Wacker-type oxyallenylation and azaallenylation of cyclic alkenes

Palladium-catalyzed three-component carboetherification of cyclic alkenes proceeded to give trans adducts exclusively with excellent enantioselectivity through a Wacker-type pathway. The reaction is also applicable to other oxygen nucleophiles, such as water, phenols, and carboxylic acids, as well as some electron-poor aryl amines.Agency for Science, Technology and Research (A*STAR)Economic Development Board (EDB)Accepted versionWe acknowledge financial support from Peking University Shenzhen Graduate School, Shenzhen Bay Laboratory (21230011-Scripps), Nanyang Technological University, the GSK-EDB Trust Fund (2017 GSK-EDB Green and Sustainable Manufacturing Award), and A*STAR Science and Engineering Research Council (AMEIRGA1783c0010).

A Wearable Biofeedback Device for Monitoring Tibial Load During Partial Weight-Bearing Walking

Patients with tibial fractures are usually advised to follow a partial weight-bearing gait rehabilitation program after surgery to promote bone healing and lower limb functional recovery. Currently, the biofeedback devices used for gait rehabilitation training in fracture patients use ground reaction force (GRF) as the indicator of tibial load. However, an increasing body of research has shown that monitoring GRF alone cannot objectively reflect the load on the lower limb bones during human movement. In this study, a novel biofeedback system was developed utilizing inertial measurement units and custom instrumented insoles. Based on the data collected from experiments, a hybrid approach combining a physics-based model and neural network architectures was used to predict tibial force. Compared to the traditional physics-based algorithm, the physical guided neural networks method showed better predictive performance. The study also found that regardless of the type of weight-bearing walking, the peak tibial force was significantly higher than the peak tibial GRF, and the time at which the peak tibial compression force occurs may not be consistent with the time at which the peak vertical GRF occurs. This further supports the idea that during gait rehabilitation training for patients with tibial fractures, monitoring and providing feedback on the actual tibial force rather than just the GRF is necessary. The developed device is a non-invasive and reliable portable device that can provide audio feedback, providing a viable solution for gait rehabilitation training outside laboratory and helping to optimize patients’ rehabilitation treatment strategies

3D S-wave velocity structure of the Ningdu basin in Jiangxi province inferred from ambient noise tomography with dense array

The Ningdu basin, located in southern Jiangxi province of southwest China, is one of the Mesozoic basin groups which has exploration prospects for geothermal energy. A study on the detailed velocity structure of the Ningdu basin can provide important information for geothermal resource exploration. In this study, we deployed a dense seismic array in the Ningdu basin to investigate the 3D velocity structure and discuss implications for geothermal exploration and geological evolution. Based on the dense seismic array including 35 short-period (5 s-100 ​Hz) seismometers with an average interstation distance of ∼5 ​km, Rayleigh surface wave dispersion curves were extracted from the continuous ambient noise data for surface wave tomographic inversion. Group velocity tomography was conducted and the 3D S-wave velocity structure was inverted by the neighborhood algorithm. The results revealed obvious low-velocity anomalies in the center of the basin, consistent with the low-velocity Cretaceous sedimentary rocks. The basement and basin-controlling fault can also be depicted by the S-wave velocity anomalies. The obvious seismic interface is about 2 ​km depth in the basin center and decreases to 700 ​m depth near the basin boundary, suggesting spatial thickness variations of the Cretaceous sediment. The fault features of the S-wave velocity profile coincide with the geological cognition of the western boundary basin-controlling fault, which may provide possible upwelling channels for geothermal fluid. This study suggests that seismic tomography with a dense array is an effective method and can play an important role in the detailed investigations of sedimentary basins