| 1. |
- Wu, Mousong, et al.
(författare)
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Coupled water transport and heat flux in seasonally frozen soils : uncertainties identification in multi-site calibration
- 2020
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Ingår i: Environmental Earth Sciences. - : Springer Nature. - 1866-6280 .- 1866-6299. ; 79:23
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Tidskriftsartikel (refereegranskat)abstract
- The modeling of seasonally frozen soils is significant for understanding the hydrological process in cold regions. The water and heat transports of two seasonally frozen sites in northern China were simulated with the process-oriented CoupModel, and a more efficient Monte Carlo based method was employed to identify the uncertainties in multi-site calibration. Results showed that water and heat measured at different sites could be explained by 15 merged parameters includingFreezepoint FWi (d(1)), EquilAdjustPsi (psi(eg)), AlbedoKExp (ka), RoughLBareSoilMom (z0M) etc. with common ranges to some extent and three parameters MinimumCondValue (k(min,uc)), WindLessExchangeSoil (r(a,max)(-1)), and SThermalCondCoef (s(k)) related to soil hydraulic conductivity, surface aerodynamic resistance and snow thermal conductivity respectively were identified to be site-dependent with site-specific ranges. The promotion in performance indices of interest variables indicated that the proposed systematic method had the potential to improve the multi-site simulation of heat and water in frozen soils based on CoupModel. However, the range ratios and posterior distributions of the merged parameters indicated the model structural uncertainty in CoupModel. And the comparison of the simulated variables between two sites demonstrated that the model structure uncertainty originated from the lack of consideration for the detailed processes related to ice cover and freezing point depression induced by soil solute. More detailed information on study sites as well as consideration of more detailed processes in frozen soil water-energy balance will expand the scope of model application in cold regions.
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| 2. |
- Qiu, Bo, et al.
(författare)
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Enhanced gut microbiota delivery of a model probiotic (Faecalibacterium prausnitzii) : Layer-by-layer encapsulation using riboflavin-conjugated sodium alginate and glycol chitosan
- 2024
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Ingår i: Food Hydrocolloids. - : Elsevier. - 0268-005X .- 1873-7137. ; 154
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Tidskriftsartikel (refereegranskat)abstract
- Faecalibacterium prausnitzii (F. prausnitzii) exhibits a variety of biological functions that make it suitable for use as a next-generation probiotic. However, its high sensitivity to oxygen and digestive fluids currently limits its application. Riboflavin is known to support the growth of F. prausnitzii in oxygen environments, but it is important that it is in close proximity to the probiotics. Layer-by-layer assembly can be used to form protective coatings around probiotics, which can protect them from adverse environmental conditions. Moreover, riboflavin can be conjugated to these coatings, thereby increasing its efficacy by bringing it close to probiotic surfaces. In this study, we therefore evaluated the potential of electrostatic layer-by-layer assembly to protect F. prausnitzii by coating them with riboflavin-alginate and glycol-chitosan layers. Initially, we showed that riboflavin could be successfully conjugated to alginate, with a grafting ratio of around 4.35%. Then, the layer-by-layer method was used to coat F. prausnitzii using cationic glycol chitosan and anionic riboflavin-alginate. The coating formed was found to have a thickness of approximately 18.5 nm. Encapsulation did not adversely affect the growth of F. prausnitzii, but it significantly enhanced its resistance to oxygen and digestive fluids. The encapsulated probiotic was shown to have enhanced mucoadhesive properties using an in vitro intestinal monolayer model. Furthermore, the encapsulated probiotics colonized the colons of rats for longer than nonencapsulated ones. These results show that coating F. prausnitzii with riboflavin-rich biopolymer layers improves its resistance to oxygen and digestive fluids, and enhances its mucoadhesion and colonization properties, which should enhance its potential as an orally administered probiotic.
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| 3. |
- Tan, Xiao, et al.
(författare)
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Design of a new TDR probe to measure water content and electrical conductivity in highly saline soils
- 2018
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Ingår i: Journal of Soils and Sediments. - : Springer Science and Business Media LLC. - 1439-0108 .- 1614-7480. ; 18:3, s. 1087-1099
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: The inappropriate irrigation is accelerating the soil salinization in western irrigation districts of China. The amelioration of salinized land must be based on large amount of water content and salinity data. Plastic coated TDR has been designed to measure water content accurately in highly saline soil, but the soil bulk electrical conductivity cannot be measured due to the coated materials. In order to measure the volumetric water content and bulk electrical conductivity in highly saline soils at the same time, a parallel three-wire TDR probe with central rod coated which was used to measure water content and a triangle three-wire TDR probe which was used to measure electrical conductivity were integrated in one probe with four rods and one slide switch. Materials and methods: The influence of angle in triangle three-wire TDR probe and the non-working rod on water content or electrical conductivity measurement were fully discussed through HFSS simulation and NaCl solution test. In the soil column experiment, four levels of salinity, 0.2, 0.4, 0.6, and 1.0% were set, the soil water content decreased from 30% in mass through the evaporation and measured by TDR and electronic balance. Then the probe was calibrated by model of Topp and Evett with these data. Results and discussion: The results show that probe has the largest EPA (polarization degree index) in angle from 97° to 138°; the non-working rod will enhance the EPA during this angle range and the four-wire probe with angle of 120° is optimal; the PVC is a better insulated material which can improve the effective salinity scope; the Evett model could improve the water content measurement greatly especially in soil with higher salinity. Conclusions: This new four-wire insulated probe can be applied as a beneficial use to monitor the moisture and electrical conductivity in highly saline soils.
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| 4. |
- Wu, Mousong, et al.
(författare)
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Simulation of dynamical interactions between soil freezing/thawing and salinization for improving water management in cold/arid agricultural region
- 2019
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Ingår i: Geoderma. - : ELSEVIER SCIENCE BV. - 0016-7061 .- 1872-6259. ; 338, s. 325-342
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Tidskriftsartikel (refereegranskat)abstract
- In cold/arid agricultural regions seasonal freezing/thawing of soils can result in soil salinization in winter; therefore, it is crucial to understand the mechanisms behind soil salinization during winter for better water management in agriculture. In Hetao Irrigation District of Inner Mongolia, northern China, we used the CoupModel (version 5) considering dynamical impacts of salt on soil freezing point to simulate soil salt dynamics and soil freezing/thawing in three winters during 2012-2015. The simulated soil temperature at different depths was improved by 10% with respect to the Nash-Sutcliffe coefficient NSE R-2 when dynamical salt impact on freezing point was taken into accounted. Simulations revealed that ice coverage on soil surface as well as water stored in drainage ditches during winter cause more severe salinization in spring due to improper Al (Autumn Irrigation) practices combining poor drainage systems. A new Al practice with earlier irrigation date (i.e. 10 d earlier than 2012/2013 winter regulation), longer irrigation period (i.e. 7 d instead of 3 d), but with less irrigation water (reduced by 20% from 2012/2013 winter regulation) was then proposed. The new AI practice can control groundwater level and salt accumulation better during winters, Our results highlight the importance of combining detailed field irrigation tests with a process-based model accounting for interactions between soil freezing/thawing and salinization to improve water management efficiency in cold/arid agricultural regions.
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| 5. |
- Wu, Mousong, et al.
(författare)
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Solute and water effects on soil freezing characteristics based on laboratory experiments
- 2015
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Ingår i: Cold Regions Science and Technology. - : Elsevier BV. - 0165-232X .- 1872-7441. ; 115, s. 22-29
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Tidskriftsartikel (refereegranskat)abstract
- Laboratory experiments were conducted to study effects of water and solute on soil freezing using TDR and temperature sensor combination methods. ANOVA methods were applied for analyzing significance for solute influences on soil freezing characteristic curve (SFCC). Results showed that higher initial water content influenced the SFCC by increasing liquid water content at the same temperature due to more water connection with soil pores, and adsorbed by soil particles. ANOVA results showed solute content and solute type all had significant effects (P < 0.001 to P < 0.5) on soil freezing processes. And solute in soil resulted in a lower freezing point of soil, which made more liquid water co-exist with ice at negative temperatures. And solute concentration condensing due to liquid water decline would also impede soil freezing processes by decreasing osmotic potential. Due to the physical and chemical process of soil solution, different ions also presented some differences in SFCC parameter estimation. Based on a trial and error method, a prediction model was also built, and it behaved well in predicting SFCC under different water and solute conditions.
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