Particle fractionation controls Escherichia coli release from solid manure

Bacteria transport through soil is a complex process particularly when the cells are released from solid manures and co-transported with particles. This study focuses on understanding of the Escherichia coli release from different particle fractions (0.25-, 0.5-, 1-, and 2-mm) of solid manure and evaluating different influent boundary conditions during cell release from manure and when a solid manure is applied to the soil. The 0.25-mm and 2-mm particle sizes resulted a greater cell release compared to 0.5-mm and 1-mm fractions (p < 0.05). The shape and magnitude of the cell release curves (CRCs) from the original manure bulk were mainly influenced by the two 0.25-mm and 2-mm fractions, respectively. The arithmetic mean for normalizing the CRCs and the time variable- based normalized CRCs for the manure-treated soil were the robust variables in evaluation of the experimental data. However, a single maximum bacteria concentration could provide the realistic dataset for the modeling process. Evaluation of the root-mean-squared-error and Akaike criterion showed that the two- and three-parametric models are recommended for simulating the cell release from solid manure in comparison with one parametric models. This study also suggests considering separate microbial release evaluations, with regards to influent concentration, for manure and manure-treated soils to propose best management practices for controlling bacteria pollution. Further research will reveal the key roles of different woody components and soluble material ratios for the various solid manures in bacteria release

Particle fractionation controls Escherichia coli release from solid manure

Funding Information: This work was supported by Shahrekord University . Nasrollah Sepehrnia was supported by Alexander von Humboldt Foundation and Postdoctoral Fellowship at Leibniz University of Hannover, Germany. Publisher Copyright: © 2021 The Author(s)Peer reviewedPublisher PD

Contrasting transport and fate of hydrophilic and hydrophobic bacteria in wettable and water-repellent porous media: Straining or attachment?

Acknowledgements This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie Grant agreement no. 101026287. We acknowledge University of Aberdeen, UK for supporting this project.Peer reviewedPublisher PD

Meshfree Methods: Moving Beyond the Cumulan! Lattice Boltzmann Method

En aquesta tesi primer s'utilitza les propietats acústiques fonamentals del métode Cumulan! Lattice Boltzmann (CLBM). Després s'aplica el métode d'elements finits als CLBM per predir l'efecte d'afegir aleles en cilindres sobre I' emissió de soroll acústica elevats nombres de Reynolds. El métode CLBM ofereix un bon resulta! compara! amb els resultats teórics, encara que pateix de problemes de precisió en utilitzar malla! uniforme. En aquest estudi es desenvolupen dos métodes MFree local weak-form CLBM, el métode local de interpolació radial puntual CLBM (LRPIC-LBM) i el métode sense malla! local Petrov-Galerkin CLBM (MLPGC-LBM). Per solucionar l'equació LB s' utilitzen dues etapes: col·lisió i propagació. L'etapa de col·lisió es modelitza mitjanc;ant el métode cumulan!. En la integració temporal de l'etapa de propagació s'utilitza el métode Lax-Wendroff i perla integració espacial s'usa la interpolació local radial i puntual per el LRPIC-LBM i el métode sense malla local de Petrov-Galerkin peral MLPGC-LBM. L'análisi deis resultats mostra la concordanc;a entre el métode LRPIC-LBM i els resultats analítics. El métode MLPGC-LBM utilitza temps de computació més curts. Finalment, aquests dos nous métodes ofereixen una alternativa al CLBM, sense tenir en compte la dependencia deis parámetres del Nppw i a.Primero se considera las propiedades acústicas fundamentales del método Cumulan! Lattice Boltzmann (CLBM). Después se aplica el método de elementos finitos acoplado al CLBM para predecir el efecto de añadir aletas en cilindros en la emisión de ruido acústico a elevados números de Reynolds. El método CLBM ofrece un buen resultado comparado con los resultados teóricos, aunque sufre de problemas de precisión al utilizar mallado uniforme. Se desarrollan dos métodos MFree local weak-form CLBM, el método local de interpolación radial puntual CLBM (LRPIC-LBM) y el método sin mallado local Petrov-Galerkin CLBM (MLPGC-LBM). La ecuación LB se divide en dos etapas: colisión y propagación. La colisión se modeliza con el método de "cumulan!". En la integración temporal de la propagación se utiliza el método de Lax-Wendroff y para la integración espacial se usa la interpolación local radial y puntual para el LRPIC-LBM y el método sin malla local de Petrov-Galerkin para el MLPGC-LBM. Los resultados muestran la concordancia entre el método LRPIC-LBM y los resultados analíticos. El método MLPGC-LBM reproduce con mas precisión los resultados del método CLBM y el método LRPIC-LBM utiliza tiempos de computación más cortos. Estos dos nuevos métodos ofrecen una alternativa al CLBM, sin dependencia de los parámetros del Nppw y a.In this dissertation, the fundamental acoustical properties of the cumulan! lattice Boltzmann method (CLBM) are first considered. Then, the coupled CLBM- finite element method is applied to predict the effect of adding hairy flaps to a cylinder on the noise emission at high Reynolds numbers. The CLBM provides a good agreement with theoretical results, while suffering from issues of accuracy related to the use of uniform meshes. Therefore, two MFree local weak-form CLB methods, the local radial point interpolation CLBM (LRPIC-LBM) and the meshless local Petrov-Galerkin CLBM (MLPGC-LBM) are suggested. The LB equation is divided into collision and streaming steps. The collision step is modeled by the cumulan! method. The streaming step is discretized in time using the Lax-Wendroff scheme. lt is discretized in space, using the local radial point interpolation method and the meshless local Petrov-Galerkin method, for LRPIC-LBM and MLPGC-LBM, respectively. The study of the results illustrates the LRPIC-LBM replicates the analytical results. The MLPGC-LBM predicts better results than the CLBM, reproducing LRPIC-LBM results with relatively shorter runtimes. Therefore, these new methods can offer an alternative to the CLBM, without parametric dependency on Nppw and a

Multiphase Phase-Field Lattice Boltzmann Method for Simulation of Soluble Surfactants

This paper proposes a phase-field model for the lattice Boltzmann method which has discretized symmetrical directions of velocities in a cartesian grid, to simulate the soluble surfactant in a Multicomponent multiphase system. Despite other existing phase-field models following Langmuir relation, the interfacial tension can be calculated analytically in this proposed model. Parameters playing roles in the models and controlling the surfactant’s strength and interaction with other phases are obtained directly from a given initial interfacial tension and bulk surfactant. Consequently, there is no further need for trial-and-error simulations, and a real system, e.g., oil-water-surfactant, can be simulated with given initial parameters. The model is validated with the analytical result for a planar oil–water-surfactant system. Furthermore, the method for reobtaining numerical interfacial tension for five different cases is tested and compared with the given initial values for an oil droplet surrounded by water and surfactant. The results show that the obtained interfacial tension from the method is in good agreement with the given initial interfacial tension. Furthermore, the spurious velocity of the model is calculated and seen that the magnitude of spurious velocities is proportional to interfacial tension

Analysis of Aeroacoustic Properties of the Local Radial Point Interpolation Cumulant Lattice Boltzmann Method

The lattice Boltzmann method (LBM) has recently been used to simulate wave propagation, one of the challenging aspects of wind turbine modeling and simulation. However, standard LB methods suffer from the instability that occurs at low viscosities and from its characteristic lattice uniformity, which results in issues of accuracy and computational efficiency following mesh refinement. The local radial point interpolation cumulant lattice Boltzmann method (LRPIC-LBM) is proposed in this paper to overcome these shortcomings. The LB equation is divided into collision and streaming steps. The collision step is modeled by the cumulant method, one of the stable LB methods at low viscosities. In addition, the streaming step, which is naturally a pure advection equation, is discretized in time and space using the Lax–Wendroff scheme and the local radial point interpolation method (RPIM), a mesh free method. We describe the propagation of planar acoustic waves, including the temporal decay of a standing plane wave and the spatial decay of a planar acoustic pulse. The analysis of these specific benchmark problems has yielded qualitative and quantitative data on acoustic dispersion and dissipation, and their deviation from analytical results demonstrates the accuracy of the method. We found that the LRPIC-LBM replicates the analytical results for different viscosities, and the errors of the fundamental acoustic properties are negligible, even for quite low resolutions. Thus, this method may constitute a useful platform for effectively predicting complex engineering problems such as wind turbine simulations, without parameter dependencies such as the number of points per wavelength Nppw and resolution σ or the detrimental effect caused by the use of coarse grids found in other accurate and stable LB models

Analysis of Aeroacoustic Properties of the Local Radial Point Interpolation Cumulant Lattice Boltzmann Method

The lattice Boltzmann method (LBM) has recently been used to simulate wave propagation, one of the challenging aspects of wind turbine modeling and simulation. However, standard LB methods suffer from the instability that occurs at low viscosities and from its characteristic lattice uniformity, which results in issues of accuracy and computational efficiency following mesh refinement. The local radial point interpolation cumulant lattice Boltzmann method (LRPIC-LBM) is proposed in this paper to overcome these shortcomings. The LB equation is divided into collision and streaming steps. The collision step is modeled by the cumulant method, one of the stable LB methods at low viscosities. In addition, the streaming step, which is naturally a pure advection equation, is discretized in time and space using the Lax–Wendroff scheme and the local radial point interpolation method (RPIM), a mesh free method. We describe the propagation of planar acoustic waves, including the temporal decay of a standing plane wave and the spatial decay of a planar acoustic pulse. The analysis of these specific benchmark problems has yielded qualitative and quantitative data on acoustic dispersion and dissipation, and their deviation from analytical results demonstrates the accuracy of the method. We found that the LRPIC-LBM replicates the analytical results for different viscosities, and the errors of the fundamental acoustic properties are negligible, even for quite low resolutions. Thus, this method may constitute a useful platform for effectively predicting complex engineering problems such as wind turbine simulations, without parameter dependencies such as the number of points per wavelength Nppw and resolution σ or the detrimental effect caused by the use of coarse grids found in other accurate and stable LB models