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A model of unfrozen water content in rock during freezing and thawing with experimental validation by nuclear magnetic resonance

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Journal of Rock Mechanics and Geotechnical Engineering 2022年第5期14卷 1545-1555页

作者： Zhouzhou Su Xianjun Tan Weizhong Chen Hailiang Jia Fei Xu State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China University of Chinese Academy of Sciences Beijing100049China College of Architecture and Civil Engineering Xi’an University of Science and TechnologyXi’an710054China Structural Health Monitoring and Control Institute Shijiazhuang Tiedao UniversityShijiazhuang050043China

The unfrozen water content of rock during freezing and thawing has an important influence on its physical and mechanical *** study presented a model for calculating the unfrozen water content of rock during freezing and thawing process,considering the influence of unfrozen water film and rock pore structure,which can reflect the hysteresis and super-cooling *** pore size distribution cu rves of red sandsto ne and its unfrozen water conte nt under different temperatures during the freezing and thawing process were measured using nuclear magnetic resonance(NMR) to validate the proposed *** between the experimental and calculated results indicated that the theoretical model accu rately reflected the water content change law of red sandstone during the freezing and thawing ***,the influences of Hamaker constant and surface relaxation parameter on the model results were *** results showed that the appropriate magnitude order of Hamaker constant for the red sandstone was 10J to 10J;and when the relaxation parameter of the rock surface was within 25-30 μm/ms,the calculated unfrozen water content using the proposed model was consistent with the experimental value.

关键词： freezing and thawing Unfrozen water content Super-cooling and hysteresis Nuclear magnetic resonance(NMR) Unfrozen water calculation model Red sandstone

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Alternate freezing and thawing enhanced the sediment and nutrient runoff loss in the restored soil of the alpine mining area

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Journal of Mountain Science 2022年第6期19卷 1823-1837页

作者： LI Fa-Yong LUO Ren-jie YOU Yong-jun HU Xue-fei QIAN Xiao-yan ZHANG Peng-yan WANG Shan LI Guo-yu KAMEL Mohamed Eltohamy College of Water Resources and Architectural Engineering Tarim UniversityAral City 843300China State Key Laboratory of Frozen Soil Engineering Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China Water Relations and Field Irrigation Department Agricultural and Biological Research DivisionNational Research CentreCairo 12622Egypt

This study highlights the influence of freezing-thawing processes on soil erosion in an alpine mine restoration area. Accordingly, a series of simulation experiments were conducted to investigate runoff, sediment, and nutrient losses, and potential influencing factors under freeze-thaw(FT) conditions. Three FT treatments(i.e., 0, 3, and 5 FT cycles), and two soil moisture contents(SMCs;i.e., 10% and 20% SMC on a gravimetric basis) were assessed. The runoff, sediment yield, ammonia nitrogen(AN), nitrate nitrogen(NN), total phosphorus(TP), and dissolved phosphorus(DP) losses from runoff were characterized under different rainfall durations. The fitting results indicated that the runoff rate and sediment rate, AN, NN, TP, and DP concentrations in runoff could be described by exponential functions. FT action increased the total runoff volume and sediment yield by 14.6%–26.0% and 8.8%–35.2%, respectively. The runoff rate and sediment rate increased rapidly with the increment of FT cycles before stabilizing. At 20% SMC, the total runoff volume and sediment yield were significantly higher than those at 10% SMC. The loss curves of AN and NN concentrations varied due to differences in their chemical properties. FT action and high SMC promoted AN and NN losses, whereas the FT cycles had little effect. FT action increased TP and DP losses by 60.2%–220.1% and 48.4%–129.8%, respectively, compared to cases with no FT action;the highest TP and DP losses were recorded at 20% SMC. This study provides a deep understanding of freezing-thawing mechanisms in the soils of alpine mine restoration areas and the influencing factors of these mechanisms on soil erosion, thereby supporting the development of erosion prevention and control measures in alpine mine restoration areas.

关键词： freezing and thawing Mine restoration area nitrogen loss Phosphorus loss Rainfall simulation Soil moisture content

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The Relations of Change Rate of Constitutive Variables for the freezing and thawing of Water Saturated Porous Media

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Journal of Modern Transportation 1999年第2期16卷 173-180页

作者：陆宏轮

The relations of change rate of an independent variable, volumetric strain of the porous skeleton, with the change rates of a kind of constitutive variables, such as porosity, volumetric strain of the solid matrix, are derived from the definition of the porosity of water saturated porous media; and the relations of the change rates of another two independent variables, pressure of the pore liquid water and temperature, with the change rates of another kind of constitutive variables, such as pressure of the pore ice, average pressure of the pore liquid water and ice, and average stress of the solid matrix, are obtained from the Clausius Clapeyron relation in the process of freezing or thawing, definitions of the average pore pressure and effective stress. Based on the hypothesis of linear thermoelasticity, principle of effective stress and these relations, the change rates of all constitutive variables may be described with the change rates of the three independent variables.

关键词： change rate constitutive variables independent variables freezing and thawing porous media

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Update on techniques for cryopreservation of human spermatozoa

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Asian Journal of Andrology 2022年第6期24卷 563-569页

作者： Chuan Huang Yu-Lin Tang Jian-Ling Hu Wen-Jun Zhou Zeng-Hui Huang Xue-Feng Luo Zheng Li Wen-Bing Zhu Institute of Reproductive and Stem Cell Engineering Basic Medicine CollegeCentral South UniversityChangsha 410000China Reproductive and Genetic Hospital of CITIC-Xiangya Changsha 410000China Department of Andrology Center for Men's HealthShanghai General HospitalShanghai Key Lab of Reproductive MedicineShanghai 200025China

In the 1960s,sperm cryopreservation was developed as a method to preserve ***,techniques for the cryopreservation of human spermatozoa have been widely used in assisted ***,although sperm cryobiology has made notable achievements,the optimal method for the recovery of viable spermatozoa after cryopreservation remains *** sperm quality can be affected by cryoprotectants,ice formation,storage conditions,and osmotic stress during the freezing *** review discusses recent advances in different cryopreservation techniques,cryoprotectants,and freezing and thawing methods during cryopreservation and new indications for the use of cryopreserved spermatozoa.

关键词： cryodamage cryoprotectant dry preservation freezing and thawing sperm cryopreservation

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Study on the Possibility of Raw Seawater into Drinking Water—A Religious Water Literacy

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Journal of Water Resource and Protection 2023年第11期15卷 631-676页

作者： Akira Hiratsuka Yoshiro Yasuda Marco Ruggiero Japan International Cooperation Agency (Former Expert) Kyoto Japan Department of Management University of Hyogo Kobe Japan National Coalition of Independent Scholars Battleboro USA

This paper explores the conversion of raw seawater into drinking water from a religious water literacy (RWL) perspective. RWL is here defined as a socially just water literacy that is based on the respect for the dignity of life of all living beings on the Earth. It discusses the importance of sustainable water sources and proposes purification methods. That is, the study aims to show a brief outline of the drinking water source (inland waters;mainly river water) and their purification technologies in recent times and today and propose the purification method (freezing-thawing-UV method) in case of taking the seawater as the source. And, it emphasizes the need for dialogue and cooperation between countries in order to proceed. The paper also discusses the relationship among religion, culture, and civilization, and highlights the similarities between Marx’s historical materialism and Umesao’s ecological view. It further discusses the importance of water purification technology, separation methods, and the potential for seawater as an energy source. The paper concludes by discussing the importance of dialogue, communication and understanding environmental decision-making. In order to carry them forward, it is convinced that citizens in the world are nothing but people with self-awareness of “Bodhisattvas of the Earth” as identities. As a result, the new findings that suggest the possibility of raw seawater into drinking water from a religious water literacy perspective through the lens of Kawakatsu’s maritime view have been obtained.

关键词： Raw Seawater Drinking Water freezing and thawing UV-A&B Religious Water Literacy

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