New insights into silt density index and modified fouling index measurements

2008 ◽  
Vol 8 (4) ◽  
pp. 401-411 ◽  
Author(s):  
A. Nahrstedt ◽  
J. Camargo-Schmale
Keyword(s):  
Boundary Conditions ◽  
Membrane Area ◽  
Filter Holder ◽  
Feed Pressure ◽  
Exact Boundary ◽  
Density Index ◽  
Different Types ◽  
Robust Parameter ◽  
Modified Fouling Index ◽  
Silt Density Index

In order to investigate the accuracy and reproducibility of the parameters SDI (silt density index) and MFI (modified fouling index), tests in diverse conditions were performed: with three different types of filter holder, two microfilter pore sizes, with and without permeate spacer and with two foulants (alginate as organic foulant and silica flour as the particulate). Additionally the effect of pressure on fouling indices was analysed. It was concluded, that there is a need to define more boundary conditions in the ASTM standard (exact type of filter holder, exact type of membrane, start conditions) for the SDI to achieve a parameter with reliable and comparable values. But in comparison to MFI, SDI seems to be a more robust parameter for a use in practice pertaining to the influence of a feed pressure level and the effective membrane area. The MFI gives more insights in acting mechanisms and offers advantages for research. It shows a correlation to a concentration of particulate or organic foulants. Like the SDI, it is necessary to define and standardize exact boundary conditions for the MFI tests (classified by the use of MF, UF or NF filter media).

scholarly journals The sensitivity of SDI and MFI to a change in particle concentration and properties under saline conditions

2012 ◽  
Vol 2 (3) ◽  
pp. 140-148
Author(s):  
N. Prihasto ◽  
Seung-Hyun Kim
Keyword(s):  
Particle Size ◽  
Ionic Strength ◽  
Particle Concentration ◽  
Relative Proportion ◽  
Saline Condition ◽  
Particle Properties ◽  
Silica Suspension ◽  
Density Index ◽  
Modified Fouling Index ◽  
Silt Density Index

The sensitivity of existing fouling indices of SDI (silt density index) and MFI (modified fouling index) to a change in particle concentration and properties was evaluated in this study. The MFI formula predicts an increased fouling tendency when the particle concentration increases and the particle size and density decrease. Consequently, concentration, size and density were selected as parameters to examine. For this purpose, silica particles and Aldrich humic acid (HA) were selected as target foulants because of the substantial difference in their size and density. According to this study, both SDI and MFI were sensitive to a change in particle properties of size and density, while MFI was more sensitive to a change in particle concentration than SDI. It is also found that the fouling tendency could be represented better by separate evaluation of T0 and T15 than SDI, at which the ratio of T0 and T15 is evaluated. T15 is found to be as sensitive as the MFI for both silica suspension and HA solution. The saline condition increased the fouling index. MFI and T15 were sensitive to a change in ionic strength. When inorganic and organic foulants were mixed, their relative proportion determined the fouling index values.

Silt Density Index and Modified Fouling Index relation, and effect of pressure, temperature and membrane resistance

Desalination ◽  
2011 ◽  
Vol 273 (1) ◽  
pp. 48-56 ◽  
Author(s):  
A. Alhadidi ◽  
A.J.B Kemperman ◽  
B. Blankert ◽  
J.C. Schippers ◽  
M. Wessling ◽  
...  
Keyword(s):  
Membrane Resistance ◽  
Effect Of Pressure ◽  
Density Index ◽  
Modified Fouling Index ◽  
Silt Density Index

scholarly journals An Advanced Galerkin Approach to Solve the Nonlinear \\[6pt]Reaction-Diffusion Equations With Different Boundary Conditions

2022 ◽  
Vol 14 (1) ◽  
pp. 30
Author(s):  
Hazrat Ali ◽  
Md. Kamrujjaman ◽  
Md. Shafiqul Islam
Keyword(s):  
Boundary Conditions ◽  
Reaction Diffusion ◽  
Reaction Diffusion Equations ◽  
Parabolic Partial Differential Equations ◽  
Galerkin Finite Element Method ◽  
Galerkin Finite Element ◽  
Nonlinear Parabolic ◽  
Comparison Results ◽  
Different Types ◽  
Convergence And Stability Analysis

This study proposed a scheme originated from the Galerkin finite element method (GFEM) for solving nonlinear parabolic partial differential equations (PDEs) numerically with initial and different types of boundary conditions. The scheme is applied generally handling the nonlinear terms in a simple way and throwing over restrictive assumptions. The convergence and stability analysis of the method are derived. The error of the method is estimated. In the series, eminent problems are solved, such as  Fisher's equation, Newell-Whitehead-Segel equation, Burger's equation, and  Burgers-Huxley equation to demonstrate the validity, efficiency, accuracy, simplicity and applicability of this scheme. In each example, the comparison results are presented both numerically and graphically

scholarly journals ANALYSIS OF STUDENT FORMULA CAR FOR OPTIMUM SAFETY AND PERFORMANCE

2020 ◽  
pp. 137-142
Author(s):  
Rabi Pathak
Keyword(s):  
Boundary Conditions ◽  
Weight Reduction ◽  
Structural Performance ◽  
Complete Analysis ◽  
Loading Conditions ◽  
Different Types ◽  
And Performance ◽  
Reliability Performance ◽  
Ansys Workbench

The Formula Student competitions are held everyyear. This paper is the result of the analysis done on the sample car design that can be presented in the Formula Student competition. The purpose of the paper is to provide a final summary on chassis analysis and structural performance. It also talks about all the important analysis that is to be done on a Formula Student car to make it safe and perform well on the track. The design has been made such that it focusses on maximum adjustability, reliability, performance, safety, weight reduction and ease of manufacturing. The analysis was done to make sure the objectives of design are fulfilled. After going through many papers, documents, blogs and videos we found that many people get confused about the loading conditions and boundary conditions for different types of tests so this paper prioritizes to make people understand about those conditions as well as about the major tests required to perform complete analysis of Formula Student cars. The weight of the chassis was calculated as 36 kg approximately according to the data obtained from design modeler of Ansys workbench as well as Solidworks. The design sustained all the loading conditions and passed all the tests. Thus, one of the objective of this paper is to help other universities and passionate students to successfully design and analyze their cars that can pass all necessary tests included in the paper. KEYWORDS—Formula Student; FEA; Boundary Conditions; Loading Conditions; Ansys; Solidworks

scholarly journals Lamb waves in multilayered media: 3D and 6D formalisms

2019 ◽  
Vol 97 ◽  
pp. 03003
Author(s):  
Anna Avershyeva ◽  
Sergey Kuznetsov
Keyword(s):  
Mathematical Model ◽  
Boundary Conditions ◽  
Fundamental Matrix ◽  
Elastic Anisotropy ◽  
Lamb Waves ◽  
Stratified Media ◽  
Multilayered Media ◽  
Different Types ◽  
Secular Equations ◽  
Fundamental Matrices

A mathematical model for analyzing Lamb waves propagating in stratified media with arbitrary elastic anisotropy is worked out. The model incorporates a combined Fundamental Matrix (FM) and Modified Transfer Matrix (MTM) methods. Multilayered unbounded plates with different types of boundary conditions imposed on the outer surfaces are considered. Closed form fundamental matrices and secular equations for dispersion relations are derived.

An iterative approach for analysis of cracks with exact boundary conditions in finite magnetoelectroelastic solids

2019 ◽  
Vol 28 (5) ◽  
pp. 055025 ◽  
Author(s):  
MingHao Zhao ◽  
QiaoYun Zhang ◽  
XinFei Li ◽  
YaGuang Guo ◽  
CuiYing Fan ◽  
...  
Keyword(s):  
Boundary Conditions ◽  
Iterative Approach ◽  
Exact Boundary ◽  
Magnetoelectroelastic Solids
Sign in / Sign up

Export Citation Format

Share Document