Manual

Velocity Menu System:

Velocity Menu:

These functions allow you to analyze previously edited velocity data with various velocity analysis methods.

1. Enhanced van Holde - Weischet
   Analyze velocity data with the enhanced van Holde - Weischet method, a model independent approach that provides diffusion-corrected S-value distributions. The analysis function is explained here. Please also refer to the van Holde - Weischet tutorial for more background information on this analysis.

2. 2-D Spectrum Analysis
   A 2-dimensional spectrum analysis which identifies the composition of mixtures of samples in terms of sedimentation and frictional properties from velocity experiments. More information about this method can be found here.

3. Finite Element (DUD)
   Analyze velocity data using the finite element analysis with the DUD fitter (Doesn't Use Derivatives). The finite element analysis will attempt whole boundary fitting which provides quantitative results for the sedimentation and diffusion coefficients, as well as partial concentrations for each component. The DUD nonlinear least squares fitter is fairly robust and works well for most problems and on machines with memory limitations. More information about this function can be found here.

4. C(s) analysis
   This method provides sedimentation coefficient distributions and average frictional ratios by the C(s) approach by P. Schuck. More information about this method can be found here.

5. Finite Element Model Viewer
   This routine will take a velocity experiment and calculate residuals for a user-provided finite element model. This model can be obtained either from a 2-D spectrum analysis, C(s) analysis, or manually generated with the Finite Element Simulator. More information is available here.

6. Initialize GA Grid
   This routine will take a sedimentation distribution from either the van Holde - Weischet analysis, the 2-dimensional spectrum analysis, the finite element nonlinear least squares fitting analysis, or the C(s) analysis and create a Genetic Algorithm initialization file that can be used to initialize the parallel supercomputer interface for the genetic algorithm analysis. More information is available here.

7. Second Moment
   The second moment analysis allows you to analyze velocity data for weight-average sedimentation coefficients. This method is useful for diagnostics such as aggregation, degradation, concentration dependency and time dependent trends. More information about this function can be found here.

8. Time Derivative
   The time derivative method allows you obtain g(s) distribtutions (not diffusion corrected) of your velocity data. The benefit of this method is its ability to automatically subtract out time-invariant noise that is often present at significant amounts in interference data. The time derivative method incurs a penalty of random noise by a factor of squareroot of 2. More information about this function can i be found here.

9. Radial Derivative
   The radial derivative methods allows you to find the midpoint (point of steepest slope) in the boundary. It works best for samples with small diffusion coefficients and produces peaks that are proportional to the relative concentration for multiple components. More information about this function can be found here.