The Experts below are selected from a list of 1086 Experts worldwide ranked by ideXlab platform

Bingcai Pan - One of the best experts on this subject based on the ideXlab platform.

  • a Settling Curve modeling method for quantitative description of the dispersion stability of carbon nanotubes in aquatic environments
    Journal of Environmental Sciences-china, 2015
    Co-Authors: Lixia Zhou, Dunxue Zhu, Shujuan Zhang, Bingcai Pan
    Abstract:

    Abstract Understanding the aggregation and deposition behavior of carbon nanotubes (CNTs) is of great significance in terms of their fate and transport in the environment. Attachment efficiency is a widely used index for well-dispersed CNT solutions. However, in natural waters, CNTs are usually heterogeneous in particle size. The attachment efficiency method is not applicable to such systems. Describing the dispersion stability of CNTs in natural aquatic systems is still a challenge. In this work, a Settling Curve modeling (SCM) method was developed for the description of the aggregation and deposition behavior of CNTs in aqueous solutions. The effects of water chemistry (natural organic matter, pH, and ionic strength) on the aggregation and deposition behavior of pristine and surface-functionalized multi-walled carbon nanotubes (MWCNTs) were systematically studied to evaluate the reliability of the SCM method. The results showed that, as compared to particle size and optical density, the centrifugal sedimentation rate constant (ks) from the Settling Curve profile is a practical, useful and reliable index for the description of heterogeneous CNT suspensions. The SCM method was successfully applied to MWCNT in three natural waters. The constituents in water, especially organic matter, determine the dispersion stability of MWCNTs in natural water bodies.

Michael K Stenstrom - One of the best experts on this subject based on the ideXlab platform.

  • practical identifiability and uncertainty analysis of the one dimensional hindered compression continuous Settling model
    Water Research, 2016
    Co-Authors: Michael K Stenstrom
    Abstract:

    The practical application of the one-dimension hindered-compression Settling models remains a challenge, since the model calibration strongly depends on experimental observations with limited information. In this study, the identifiability of parameter subsets of the hindered-compression models is evaluated for various experimental layouts. Global sensitivity analysis is used to preliminarily select the influential parameters which can be reasonably estimated, while the identifiability analysis of parameter subsets is conducted based on the local sensitivity functions and collinearity measures. The batch Settling Curve observations are informative for calibrating hindered parameters, and to determine the compression parameters, the concentration profile observations may need to be collected. For different experimental layouts, at least three parameters are identifiable, and the number of identifiable parameters can potentially increase to five, if both batch Settling Curve and concentration observations are available. The parameter subset identifiability is sensitive to the choice of initial parameter values, and determining the initial values of hindered parameters and gel concentration by measuring the hindered Settling velocities and the top concentration of the static sediment respectively allows efficient reduction of the sensitivity. Parameter subset estimates are sensitive to the values of fixed parameters, and reliable estimation of identifiable parameter subsets is possible to significantly decrease model prediction uncertainties.

Esa K Renko - One of the best experts on this subject based on the ideXlab platform.

  • modelling hindered batch Settling part i a model for linking zone Settling velocity and stirred sludge volume index
    Water SA, 1998
    Co-Authors: Esa K Renko
    Abstract:

    A new type of model for describing the relationship between zone Settling velocity (V s) and stirred sludge volume index (SSVI) is developed. Compared to the earlier studies which link SSVI and V s (to reduce multiple batch tests when collecting X-V s data), the proposed model is more advantageous because it also describes regions of low solids concentrations. The model is derived fr om the model for batch Settling Curve and is expressed as , where C and β are parameters describing zone Settling velocity and X is the activated sludge concentration. The applicability of the relationship was tested by analysing data publis hed earlier in the literature. Based on these data it was found that the model can be used in wide ranges of SSVI and sludge conce ntration. A modified Vesilind model is also introduced and written as , where n and ν are parameters describing zone Settling velocity.

  • modelling hindered batch Settling part ii a model for computing solids profile of calcium carbonate slurry
    Water SA, 1998
    Co-Authors: Esa K Renko
    Abstract:

    This study suggests a hypothesis for determining and a model for computing suspended solids behaviour during batch Settling aimed at better understanding of the Settling process and more accurate and convenient determination of solids profiles. The approach is built on the graphical approach of Work and Kohler taking into account the effect of scale (i.e . initial height of suspension) on the Settling of the surface of suspension. It is shown that the proposed approach includes the same information as the traditional Kynch theory of sedimentation. The proposed model, derived from the hypothesis and a model for a batch Settling Curve, introduces a mathematical tool for determining the solids layers and it also eliminates the disadvantage of the Kynch th eory which only offers a graphical procedure for the determination. The applicability of the model was tested with calcium carbonate (CaCO3) suspension. The experimental study proves that the model can be successfully utilised in computing the behaviour of calcium carbonate during a batch Settling test.

Tong F - One of the best experts on this subject based on the ideXlab platform.

  • Experimental study on complete consolidation behavior of Hong Kong marine deposits
    Taylor & Francis, 2012
    Co-Authors: Tong F, Jh Yin, Pei H
    Abstract:

    The time-dependent feature of soft soils has gained intensive attraction in recent years. Due to the high water content and viscous property, the Hong Kong marine deposit (HKMD) frequently poses a challenge to geotechnical practice, particularly to the reclamation in Hong Kong. A key issue related to reclamation design, foundation construction and maintenance is excess settlement/deformation of the ground. Formation of HKMD typically goes through sedimentation and self-weight consolidation. A series of one-dimensional Settling column consolidation tests, together with conventional oedometer tests were conducted on the HKMD. By normalizing parameter in Settling stage, a unique global relationship of effective stress, σ z′ and strain, ε{lunate} z could be established. Results reveal that the Settling Curve and Settling rate are significantly affected by the sediment concentration in self-weight consolidation. After the primary self-weight consolidation, the Settling rate is reduced in the "secondary self-weight consolidation.".Department of Civil and Environmental Engineerin

  • Experimental study on Settling consolidation behavior of Hong Kong marine deposits
    Faculty of Construction and Land Use Hong Kong Polytechnic University, 2011
    Co-Authors: Tong F, Jh Yin
    Abstract:

    The time-dependent feature of soft soils has gained intensive attraction in recent years. Due to the high water content and viscous property, the Hong Kong marine deposit (HKMD) frequently poses challenge to geotechnical practice, particularly to the reclamation in Hong Kong. A key issue regarding reclamation design, foundation construction and maintenance is excess settlement/deformation of the ground. Formation of HKMD typically goes through sedimentation and self-weight consolidation. A series of one-dimensional Settling column consolidation tests are conducted on the HKMD. Results reveal that the Settling Curve and Settling rate are significantly affected by the sediment concentration. Further study is conducted on the viscous behaviour in self-weight consolidation. Related parameters from sketches are evaluated for a better interpretation of the whole Settling and consolidation behaviors.Department of Civil and Environmental Engineerin

  • Experimental investigation on Settling behaviour of Hong Kong marine deposits in Settling column condition
    2011
    Co-Authors: Tong F, Jh Yin, Gf Zhu
    Abstract:

    Due to the high water content and viscous property, the Hong Kong marine deposit (HKMD) frequently poses challenge to geotechnical practice, particularly to the reclamation in Hong Kong. Formation of HKMD typically goes through sedimentation and self-weight consolidation. These behaviours are time-dependent and hard to describe. A series of one-dimensional Settling column consolidation tests were conducted on the HKMD. Results reveal that the Settling Curve and Settling rate are significantly affected by the sediment concentration in self-weight consolidation. Soils even exhibit viscosity in self-weight consolidation. After the primary self-weight consolidation, the Settling rate is reduced in the "secondary consolidation". Related parameters from sketches are evaluated for a better interpretation of the consolidation behaviour.Department of Civil and Environmental Engineerin

Jh Yin - One of the best experts on this subject based on the ideXlab platform.

  • Experimental study on complete consolidation behavior of Hong Kong marine deposits
    Taylor & Francis, 2012
    Co-Authors: Tong F, Jh Yin, Pei H
    Abstract:

    The time-dependent feature of soft soils has gained intensive attraction in recent years. Due to the high water content and viscous property, the Hong Kong marine deposit (HKMD) frequently poses a challenge to geotechnical practice, particularly to the reclamation in Hong Kong. A key issue related to reclamation design, foundation construction and maintenance is excess settlement/deformation of the ground. Formation of HKMD typically goes through sedimentation and self-weight consolidation. A series of one-dimensional Settling column consolidation tests, together with conventional oedometer tests were conducted on the HKMD. By normalizing parameter in Settling stage, a unique global relationship of effective stress, σ z′ and strain, ε{lunate} z could be established. Results reveal that the Settling Curve and Settling rate are significantly affected by the sediment concentration in self-weight consolidation. After the primary self-weight consolidation, the Settling rate is reduced in the "secondary self-weight consolidation.".Department of Civil and Environmental Engineerin

  • Experimental study on Settling consolidation behavior of Hong Kong marine deposits
    Faculty of Construction and Land Use Hong Kong Polytechnic University, 2011
    Co-Authors: Tong F, Jh Yin
    Abstract:

    The time-dependent feature of soft soils has gained intensive attraction in recent years. Due to the high water content and viscous property, the Hong Kong marine deposit (HKMD) frequently poses challenge to geotechnical practice, particularly to the reclamation in Hong Kong. A key issue regarding reclamation design, foundation construction and maintenance is excess settlement/deformation of the ground. Formation of HKMD typically goes through sedimentation and self-weight consolidation. A series of one-dimensional Settling column consolidation tests are conducted on the HKMD. Results reveal that the Settling Curve and Settling rate are significantly affected by the sediment concentration. Further study is conducted on the viscous behaviour in self-weight consolidation. Related parameters from sketches are evaluated for a better interpretation of the whole Settling and consolidation behaviors.Department of Civil and Environmental Engineerin

  • Experimental investigation on Settling behaviour of Hong Kong marine deposits in Settling column condition
    2011
    Co-Authors: Tong F, Jh Yin, Gf Zhu
    Abstract:

    Due to the high water content and viscous property, the Hong Kong marine deposit (HKMD) frequently poses challenge to geotechnical practice, particularly to the reclamation in Hong Kong. Formation of HKMD typically goes through sedimentation and self-weight consolidation. These behaviours are time-dependent and hard to describe. A series of one-dimensional Settling column consolidation tests were conducted on the HKMD. Results reveal that the Settling Curve and Settling rate are significantly affected by the sediment concentration in self-weight consolidation. Soils even exhibit viscosity in self-weight consolidation. After the primary self-weight consolidation, the Settling rate is reduced in the "secondary consolidation". Related parameters from sketches are evaluated for a better interpretation of the consolidation behaviour.Department of Civil and Environmental Engineerin