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Chen X, Liu Y, Jiang Y, Feng S. Radon transport carried by geogas: prediction model. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:86656-86675. [PMID: 37436618 DOI: 10.1007/s11356-023-28616-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 07/01/2023] [Indexed: 07/13/2023]
Abstract
This paper provides an overview and information on radon migration in the crust. In the past several decades, numerous studies on radon migration have been published. However, there is no there is no comprehensive review of large-scale radon transport in the earth crust. A literature review was conducted to present the research on the mechanism of radon migration, geogas theory, investigation of multiphase flow, and modeling method of fractures. Molecular diffusion was long considered the primary mechanism for radon migration in the crust. However, a molecular diffusion mechanism cannot explain the understanding of anomalous radon concentrations. In contrast with early views, the process of radon migration and redistribution within the Earth may be determined by geogas (mainly CO2 and CH4). Microbubbles rising in fractured rocks may be a rapid and efficient way of radon migration, as reported by recent studies. All these hypotheses on the mechanisms of geogas migration are summarized into a theoretical framework, defined as "geogas theory." According to geogas theory, fractures are the principal channel of gas migration. The development of the discrete fracture network (DFN) method is expected to supply a new tool for fracture modeling. It is hoped that this paper will contribute to a deeper understanding of radon migration and fracture modeling.
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Affiliation(s)
- Xiaojie Chen
- School of Resource Environment and Safety Engineering, University of South China, Hengyang, 421001, Hunan, China
- Safety Technology Center, University of South China, Hengyang, 421001, Hunan, China
| | - Yong Liu
- College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060, China
| | - Yourui Jiang
- School of Resource Environment and Safety Engineering, University of South China, Hengyang, 421001, Hunan, China
| | - Shengyang Feng
- School of Resource Environment and Safety Engineering, University of South China, Hengyang, 421001, Hunan, China.
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Ettoumi FE, Zhang R, Belwal T, Javed M, Xu Y, Li L, Weide L, Luo Z. Generation and characterization of nanobubbles in ionic liquid for a green extraction of polyphenols from Carya cathayensis Sarg. Food Chem 2022; 369:130932. [PMID: 34461511 DOI: 10.1016/j.foodchem.2021.130932] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 08/16/2021] [Accepted: 08/19/2021] [Indexed: 12/26/2022]
Abstract
Nanobubbles (NBs) generated-nanojets membrane poration have gained enormous attention. In this study, NBs were fabricated as a novel green approach to assist ionic liquid (IL) [C4C1im][BF4] extraction of polyphenols from Carya cathayensis Sarg. husk. NBs were successfully generated with mean size of 85.47 ± 5 nm, zeta potential of +39 ± 2.24 mV, and concentration of 21.15 ± 0.75 × 108 particles/mL (stable for over 48 h in IL solution). Compared to common solutions extract, IL-NBs extract showed significantly higher (p < 0.05) antioxidant activity and polyphenols yields with a total polyphenol, total flavonoid, and total tannins contents of 85.67 ± 2.05 mg GAE/g DW, 42.44 ± 1.17 mg CE/g DW, and 8.2 ± 0.05 mg TAE/g DW, respectively. The SEM results confirmed that NBs' nanojets caused morphological destruction of the husk powder. Overall, IL-NBs solution showed better extraction efficiency of polyphenols than other solutions, giving insight into a new "green" nanotechnology-based extraction method.
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Affiliation(s)
- Fatima-Ezzahra Ettoumi
- Zhejiang University, College of Biosystems Engineering and Food Science, Hangzhou 310058, People's Republic of China
| | - Ruyuan Zhang
- Zhejiang University, College of Biosystems Engineering and Food Science, Hangzhou 310058, People's Republic of China
| | - Tarun Belwal
- Zhejiang University, College of Biosystems Engineering and Food Science, Hangzhou 310058, People's Republic of China
| | - Miral Javed
- Zhejiang University, College of Biosystems Engineering and Food Science, Hangzhou 310058, People's Republic of China
| | - Yanqun Xu
- Zhejiang University, College of Biosystems Engineering and Food Science, Hangzhou 310058, People's Republic of China; Ningbo Research Institute, Zhejiang University, Ningbo 315100, People's Republic of China
| | - Li Li
- Zhejiang University, College of Biosystems Engineering and Food Science, Hangzhou 310058, People's Republic of China
| | - Lv Weide
- Hangzhou Vocational & Technical College, Hangzhou 310018, People's Republic of China
| | - Zisheng Luo
- Zhejiang University, College of Biosystems Engineering and Food Science, Hangzhou 310058, People's Republic of China; National-Local Joint Engineering Laboratory of Intelligent Food Technology and Equipment, Key Laboratory of Agro-Products Postharvest Handling of Ministry of Agriculture and Rural Affairs, Zhejiang Key Laboratory for Agri-Food Processing, Hangzhou 310058, People's Republic of China; Ningbo Research Institute, Zhejiang University, Ningbo 315100, People's Republic of China; Fuli Institute of Food Science, Hangzhou 310058, People's Republic of China.
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LuTheryn G, Glynne-Jones P, Webb JS, Carugo D. Ultrasound-mediated therapies for the treatment of biofilms in chronic wounds: a review of present knowledge. Microb Biotechnol 2020; 13:613-628. [PMID: 32237219 PMCID: PMC7111087 DOI: 10.1111/1751-7915.13471] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Accepted: 07/21/2019] [Indexed: 12/11/2022] Open
Abstract
Bacterial biofilms are an ever-growing concern for public health, featuring both inherited genetic resistance and a conferred innate tolerance to traditional antibiotic therapies. Consequently, there is a growing interest in novel methods of drug delivery, in order to increase the efficacy of antimicrobial agents. One such method is the use of acoustically activated microbubbles, which undergo volumetric oscillations and collapse upon exposure to an ultrasound field. This facilitates physical perturbation of the biofilm and provides the means to control drug delivery both temporally and spatially. In line with current literature in this area, this review offers a rounded argument for why ultrasound-responsive agents could be an integral part of advancing wound care. To achieve this, we will outline the development and clinical significance of biofilms in the context of chronic infections. We will then discuss current practices used in combating biofilms in chronic wounds and then critically evaluate the use of acoustically activated gas microbubbles as an emerging treatment modality. Moreover, we will introduce the novel concept of microbubbles carrying biologically active gases that may facilitate biofilm dispersal.
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Affiliation(s)
- Gareth LuTheryn
- Faculty of Engineering and Physical Sciences, University of Southampton, Southampton, UK
- National Biofilms Innovation Centre, University of Southampton, Southampton, UK
| | - Peter Glynne-Jones
- Faculty of Engineering and Physical Sciences, University of Southampton, Southampton, UK
- Institute for Life Sciences, University of Southampton, Southampton, UK
| | - Jeremy S Webb
- National Biofilms Innovation Centre, University of Southampton, Southampton, UK
- Institute for Life Sciences, University of Southampton, Southampton, UK
- Centre for Biological Sciences, University of Southampton, Southampton, UK
| | - Dario Carugo
- Faculty of Engineering and Physical Sciences, University of Southampton, Southampton, UK
- National Biofilms Innovation Centre, University of Southampton, Southampton, UK
- Institute for Life Sciences, University of Southampton, Southampton, UK
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Marion S, Davis SJ, Wu ZQ, Radenovic A. Nanocapillary confinement of imidazolium based ionic liquids. NANOSCALE 2020; 12:8867-8874. [PMID: 32255450 DOI: 10.1039/d0nr01164a] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Room temperature ionic liquids are salts which are molten at or around room temperature without any added solvent or solution. In bulk they exhibit glass like dependence of conductivity with temperature as well as coupling of structural and transport properties. Interfaces of ionic liquids have been found to induce structural changes with evidence of long range structural ordering on solid-liquid interfaces spanning length scales of 10-100 nm. Our aim is to characterize the influence of confinement on the structural properties of ionic liquids. We present the first conductivity measurements on ionic liquids of the imidazolium type in single conical glass nanopores with confinements as low as tens of nanometers. We probe glassy dynamics of ionic liquids in a large range of temperatures (-20 to 70 °C) and nanopore opening sizes (20-600 nm) in silica glass nanocapillaries. Our results indicate no long range freezing effects due to confinement in nanopores with diameters as low as 20 nm. The studied ionic liquids are found to behave as glass like liquids across the whole accessible confinement size and temperature range.
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Affiliation(s)
- Sanjin Marion
- Laboratory of Nanoscale Biology, Institute of Bioengineering, School of Engineering, EPFL, 1015 Lausanne, Switzerland.
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Comparison of Bubble Size Distributions Inferred from Acoustic, Optical Visualisation, and Laser Diffraction. COLLOIDS AND INTERFACES 2019. [DOI: 10.3390/colloids3040065] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Bubble measurement has been widely discussed in the literature and comparison studies have been widely performed to validate the results obtained for various forms of bubble size inferences. This paper explores three methods used to obtain a bubble size distribution—optical detection, laser diffraction and acoustic inferences—for a bubble cloud. Each of these methods has advantages and disadvantages due to their intrinsic inference methodology or design flaws due to lack of specificity in measurement. It is clearly demonstrated that seeing bubbles and hearing them are substantially and quantitatively different. The main hypothesis being tested is that for a bubble cloud, acoustic methods are able to detect smaller bubbles compared to the other techniques, as acoustic measurements depend on an intrinsic bubble property, whereas photonics and optical methods are unable to “see” a smaller bubble that is behind a larger bubble. Acoustic methods provide a real-time size distribution for a bubble cloud, whereas for other techniques, appropriate adjustments or compromises must be made in order to arrive at robust data. Acoustic bubble spectrometry consistently records smaller bubbles that were not detected by the other techniques. The difference is largest for acoustic methods and optical methods, with size differences ranging from 5–79% in average bubble size. Differences in size between laser diffraction and optical methods ranged from 5–68%. The differences between laser diffraction and acoustic methods are less, and range between 0% (i.e., in agreement) up to 49%. There is a wider difference observed between the optical method, laser diffraction and acoustic methods whilst good agreement between laser diffraction and acoustic methods. The significant disagreement between laser diffraction and acoustic method (35% and 49%) demonstrates the hypothesis, as there is a higher proportion of smaller bubbles in these measurements (i.e., the smaller bubbles ‘hide’ during measurement via laser diffraction). This study, which shows that acoustic bubble spectrometry is able to detect smaller bubbles than laser diffraction and optical techniques. This is supported by heat and mass transfer studies that show enhanced performance due to increased interfacial area of microbubbles, compared to fine bubbles.
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