6 research outputs found

    Application of upscaling methods for fluid flow and mass transport in multi-scale heterogeneous media : A critical review

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    Physical and biogeochemical heterogeneity dramatically impacts fluid flow and reactive solute transport behaviors in geological formations across scales. From micro pores to regional reservoirs, upscaling has been proven to be a valid approach to estimate large-scale parameters by using data measured at small scales. Upscaling has considerable practical importance in oil and gas production, energy storage, carbon geologic sequestration, contamination remediation, and nuclear waste disposal. This review covers, in a comprehensive manner, the upscaling approaches available in the literature and their applications on various processes, such as advection, dispersion, matrix diffusion, sorption, and chemical reactions. We enclose newly developed approaches and distinguish two main categories of upscaling methodologies, deterministic and stochastic. Volume averaging, one of the deterministic methods, has the advantage of upscaling different kinds of parameters and wide applications by requiring only a few assumptions with improved formulations. Stochastic analytical methods have been extensively developed but have limited impacts in practice due to their requirement for global statistical assumptions. With rapid improvements in computing power, numerical solutions have become more popular for upscaling. In order to tackle complex fluid flow and transport problems, the working principles and limitations of these methods are emphasized. Still, a large gap exists between the approach algorithms and real-world applications. To bridge the gap, an integrated upscaling framework is needed to incorporate in the current upscaling algorithms, uncertainty quantification techniques, data sciences, and artificial intelligence to acquire laboratory and field-scale measurements and validate the upscaled models and parameters with multi-scale observations in future geo-energy research.© 2021 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)This work was jointly supported by the National Key Research and Development Program of China (No. 2018YFC1800900 ), National Natural Science Foundation of China (No: 41972249 , 41772253 , 51774136 ), the Program for Jilin University (JLU) Science and Technology Innovative Research Team (No. 2019TD-35 ), Graduate Innovation Fund of Jilin University (No: 101832020CX240 ), Natural Science Foundation of Hebei Province of China ( D2017508099 ), and the Program of Education Department of Hebei Province ( QN219320 ). Additional funding was provided by the Engineering Research Center of Geothermal Resources Development Technology and Equipment , Ministry of Education, China.fi=vertaisarvioitu|en=peerReviewed

    Discrimination between 5‑Hydroxymethylcytosine and 5‑Methylcytosine in DNA via Selective Electrogenerated Chemiluminescence (ECL) Labeling

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    DNA methylation is used to dynamically reprogram cells in the course of early embryonic development in mammals. 5-Hydroxymethylcytosine in DNA (5-hmC-DNA) plays essential roles in the demethylation processes. 5-Methylcytosine in DNA (5-mC-DNA) is oxidized to 5-hmC-DNA by 10–11 translocation proteins, which are relatively high abundance in embryonic stem cells and neurons. A new method was developed herein to quantify 5-hmC-DNA based on selective electrogenerated chemiluminescence (ECL) labeling with the specific oxidation of 5-hmC to 5-fC by KRuO<sub>4</sub>. A thiolated capture probe (ssDNA, 35-mer) for the target DNA containing 5-hmC was self-assembled on a gold surface. The 5-hmC in the target DNA was selectively transformed to 5-fC via oxidation by KRuO<sub>4</sub> and then subsequently labeled with <i>N</i>-(4-aminobutyl)-<i>N</i>-ethylisoluminol (ABEI). The ABEI-labeled target DNA was hybridized with the capture probe on the electrode, resulting in a strong ECL emission. An extremely low detection limit of 1.4 × 10<sup>–13</sup> M was achieved for the detection of 5-hmC-DNA. In addition, this ECL method was useful for the quantification of 5-hmC in serum samples. This work demonstrates that selective 5-hmC oxidation in combination with an inherently sensitive ECL method is a promising tactic for 5-hmC biosensing

    Fungal-Modified Lignin-Enhanced Physicochemical Properties of Collagen-Based Composite Films

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    Renewable and biodegradable materials have attracted broad attention as alternatives to existing conventional plastics, which have caused serious environmental problems. Collagen is a potential material for developing versatile film due to its biosafety, renewability, and biodegradability. However, it is still critical to overcome the low mechanical, antibacterial and antioxidant properties of the collagen film for food packaging applications. To address these limitations, we developed a new technology to prepare composite film by using collagen and fungal-modified APL (alkali pretreatment liquor). In this study, five edible and medical fungi, Cunninghamella echinulata FR3, Pleurotus ostreatus BP3, Ganoderma lucidum EN2, Schizophyllum commune DS1 and Xylariaceae sp. XY were used to modify the APL, and that showed that the modified APL significantly improved the mechanical, antibacterial and antioxidant properties of APL/Collagen composite films. Particularly, the APL modified by BP3, EN2 and XY showed preferable performance in enhancing the properties of the composite films. The tensile strength of the film was increased by 1.5-fold in the presence of the APL modified by EN2. To further understand the effect of fungal-biomodified APL on the properties of the composite films, a correlation analysis between the components of APL and the properties of composite films was conducted and indicated that the content of aromatic functional groups and lignin had a positive correlation with the enhanced mechanical and antioxidant properties of the composite films. In summary, composite films prepared from collagen and fungal biomodified APL showed elevated mechanical, antibacterial and antioxidant properties, and the herein-reported novel technology prospectively possesses great potential application in the food packaging industry
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