195 research outputs found

    Recent advances on fluid flow in porous media using digital core analysis technology

    Get PDF
    The scientific and engineering challenges of research on porous media have gained substantial attention in recent decades. These intricate issues span different disciplines and fields, manifesting in natural and industrial systems like soils, oil and gas reservoirs, tissues, plants, etc. Meanwhile, digital core analysis technology has rapidly developed, proving invaluable not just in oil and gas reservoirs development, but also in geothermal energy, carbon and hydrogen storage. The China InterPore Chapter and the Research Center of Multiphase Flow in Porous Media at China University of Petroleum (East China) have established a conference platform for global scholars to exchange ideas and research in porous media utilizing digital core analysis technology. The 6th International Conference on Digital Core Analysis & the 2023 China Interpore Conference on Porous Media was successfully held in Qingdao from July 5 to 7, 2023. The conference facilitated discussions among 150 participants, including over 20 invited experts from academia and industry, and the recent advances in research of fluid flow in porous media using digital core analysis technology were thoroughly presented.Document Type: EditorialCited as: Yang, Y., Horne, R. N., Cai, J., Yao, J. Recent advances on fluid flow in porous media using digital core analysis technology. Advances in Geo-Energy Research, 2023, 9(2): 71-75. https://doi.org/10.46690/ager.2023.08.0

    A SCALING METHOD FOR SPONTANEOUS IMBIBITION IN SYSTEMS WITH DIFFERENT WETTABILITY

    Get PDF
    ABSTRACT Wettability is a dominant parameter governing spontaneous imbibition. However less attention has been paid to the effect of wettability on the scaling of spontaneous imbibition data. A scaling model has been developed for oil-water-rock systems with different wettability based on the fluid flow mechanisms in porous media. Relative permeability, capillary pressure, initial water saturation, and wettability are considered in the scaling model. Theoretically this scaling model is suitable for both cocurrent and countercurrent spontaneous imbibition. The experimental data of countercurrent spontaneous water imbibition at different wettability cannot be scaled using the frequently used scaling model but can be scaled satisfactorily using the scaling model developed in this study. An analytical solution to the relationship between oil recovery and imbibition time for linear spontaneous imbibition has also been derived. The analytical solution predicts a linear correlation between the oil recovery by spontaneous water imbibition and the square root of imbibition time, which has been verified against experimental data

    Contributions of 3D printed fracture networks to development of flow and transport models

    Get PDF
    Conventional experiments using natural rock samples have trouble in observing rock structures and controlling fracture properties. Taking advantage of 3D printing technologies, a complex fracture network was made by using a 3D printer. This approach allowed us to control the properties of the fracture networks and to prepare identical geometries for both simulation and experiment. A tracer response curve from the flow experiment was obtained and compared with numerical simulations. The result of the computational fluid dynamics (CFD) simulation based on the Navier–Stokes equations was in good agreement with experimental result, which suggested that the results of experiment and the CFD simulation are reliable. On the other hand, comparison with an equivalent permeability model based on the cubic law showed a discrepancy from the experimental result. This validation approach enabled discussion of the limitation of the flow model. Because 3D printed fracture networks could reduce uncertainty between numerical simulation and laboratory experiment, they will be useful for understanding more detailed and more complicated phenomena in fracture networks

    Coordinated transcriptional regulation of bone homeostasis by Ebf1 and Zfp521 in both mesenchymal and hematopoietic lineages

    Get PDF
    Bone homeostasis is maintained by the coupled actions of hematopoietic bone-resorbing osteoclasts (OCs) and mesenchymal bone-forming osteoblasts (OBs). Here we identify early B cell factor 1 (Ebf1) and the transcriptional coregulator Zfp521 as components of the machinery that regulates bone homeostasis through coordinated effects in both lineages. Deletion of Zfp521 in OBs led to impaired bone formation and increased OB-dependent osteoclastogenesis (OC-genesis), and deletion in hematopoietic cells revealed a strong cell-autonomous role for Zfp521 in OC progenitors. In adult mice, the effects of Zfp521 were largely caused by repression of Ebf1, and the bone phenotype of Zfp521+/− mice was rescued in Zfp521+/−:Ebf1+/− mice. Zfp521 interacted with Ebf1 and repressed its transcriptional activity. Accordingly, deletion of Zfp521 led to increased Ebf1 activity in OBs and OCs. In vivo, Ebf1 overexpression in OBs resulted in suppressed bone formation, similar to the phenotype seen after OB-targeted deletion of Zfp521. Conversely, Ebf1 deletion led to cell-autonomous defects in both OB-dependent and cell-intrinsic OC-genesis, a phenotype opposite to that of the Zfp521 knockout. Thus, we have identified the interplay between Zfp521 and Ebf1 as a novel rheostat for bone homeostasis

    OGLE-2005-BLG-071Lb, the Most Massive M-Dwarf Planetary Companion?

    Get PDF
    We combine all available information to constrain the nature of OGLE-2005-BLG-071Lb, the second planet discovered by microlensing and the first in a high-magnification event. These include photometric and astrometric measurements from Hubble Space Telescope, as well as constraints from higher order effects extracted from the ground-based light curve, such as microlens parallax, planetary orbital motion and finite-source effects. Our primary analysis leads to the conclusion that the host of Jovian planet OGLE-2005-BLG-071Lb is an M dwarf in the foreground disk with mass M= 0.46 +/- 0.04 Msun, distance D_l = 3.3 +/- 0.4 kpc, and thick-disk kinematics v_LSR ~ 103 km/s. From the best-fit model, the planet has mass M_p = 3.8 +/- 0.4 M_Jup, lies at a projected separation r_perp = 3.6 +/- 0.2 AU from its host and so has an equilibrium temperature of T ~ 55 K, i.e., similar to Neptune. A degenerate model less favored by \Delta\chi^2 = 2.1 (or 2.2, depending on the sign of the impact parameter) gives similar planetary mass M_p = 3.4 +/- 0.4 M_Jup with a smaller projected separation, r_\perp = 2.1 +/- 0.1 AU, and higher equilibrium temperature T ~ 71 K. These results from the primary analysis suggest that OGLE-2005-BLG-071Lb is likely to be the most massive planet yet discovered that is hosted by an M dwarf. However, the formation of such high-mass planetary companions in the outer regions of M-dwarf planetary systems is predicted to be unlikely within the core-accretion scenario. There are a number of caveats to this primary analysis, which assumes (based on real but limited evidence) that the unlensed light coincident with the source is actually due to the lens, that is, the planetary host. However, these caveats could mostly be resolved by a single astrometric measurement a few years after the event.Comment: 51 pages, 12 figures, 3 tables, Published in Ap

    Distinctiveness of psychological obstacles to recovery in low back pain patients in primary care

    Get PDF
    Many psychological factors have been suggested to be important obstacles to recovery from low back pain, yet most studies focus on a limited number of factors. We compared a more comprehensive range of 20 factors in predicting outcome in primary care. Consecutive patients consulting 8 general practices were eligible to take part in a prospective cohort study; 1591 provided data at baseline and 810 at 6 months. Clinical outcome was defined using the Roland and Morris Disability Questionnaire (RMDQ). The relative strength of the baseline psychological measures to predict outcome was investigated using adjusted multiple linear regression techniques. The sample was similar to other primary care cohorts (mean age 44 years, 59% women, mean baseline RMDQ 8.6). The 20 factors each accounted for between 0.04% and 33.3% of the variance in baseline RMDQ score. A multivariate model including all 11 scales that were associated with outcome in the univariate analysis accounted for 47.7% of the variance in 6 months RMDQ score; rising to 55.8% following adjustment. Four scales remained significantly associated with outcome in the multivariate model explaining 56.6% of the variance: perceptions of personal control, acute/chronic timeline, illness identify and pain self-efficacy. When all independent factors were included, depression, catastrophising and fear avoidance were no longer significant. Thus, a small number of psychological factors are strongly predictive of outcome in primary care low back pain patients. There is clear redundancy in the measurement of psychological factors. These findings should help to focus targeted interventions for back pain in the future
    corecore