CONTIN program

Laplace transformation of eqn 1.1 (often using the CONTIN program (Provencher 1982)) yields the distribution of relaxation times, A(t). The decay rates of the relaxation modes provide translational diffusion coefficients. 

In any case, the rate distribution function P(r), or the discrete pk, must first be determined from t,het(t) or g (t). Since this Laplace inversion is highly unstable, it is necessary to impose additional constraints, and various algorithms have been proposed in the literature [53,54,56,57,58,59]. Thorough discussions of these methods with respect to PCS data can be found in Ref. [60,61,62]. Here we will concentrate on the CONTIN program developed by Provencher [53,54,57]. 

Figure 10.4 Hole size distribution curves (determined using the CONTIN program) for PMMA at various temperatures.

S.W. Provencher CONTIN program, EMBL Technical Reporty DA 05, European Biology Laboratory, Germany 1982 Comput. Phys. Commum., 27, 229 (1982)... 

Dlubek, G., Hiibner, Ch., and Eichler, S., Do the MELT or CONTIN programs accurately reveal the o-Ps lifetime distribution in polymers Analysis of experimental lifetime spectra of amorphous polymers, Nucl. Instrum. Methods Phys. Res. B, 142, 191-202 (1998a). 

Figure 7. Comparison of the hole size distribution before (O) and after ( ) CO2 conditioning of polyimides and polyethylene. The experiments are the same as in Fig.6, but the data are analyzed to extract the distribution using the CONTIN program. (Reproduced with permission from ref 21, copyright The Chemical Society of Japan)...

Cao, H., G. H. Dai, J.-P. Yuan, and Y. C. Jean. 1997. Reliability of ortho-positronium lifetime distribution analysis in polymers by using CONTIN program. Materials Science Forum 255-257 238-242. 

Table IV shows a conqtarison of PAL spectra in PTMSP and a dense PPO film (crystallinity of about 40%) obtained using PATFIT and CONTIN programs. It is seen that PPO has a PAL spectrum typical of most polymeric materials the intermediate positron lifetime conqranent %2 is close to 0.4 ns, whereas the o-Ps conqmnent is in the range of 2-3 ns.

Table IV. Comparison of lifetime distributions of positron aimihilation in dense films of MSP and PPO using PATFIT and CONTIN programs.

The work was supported by the Russian Foundation of Basic Research (Grant 95-03-08325). The research described in this publication was made possible in part by Award No RC2-347 of the U.S. Civil Research and Development Foundation for the Independent States of the Former Soviet Union (CRDF). The authors are grateful to Dr. V.S. Khotimsky who prepared the PTMSP sample, Dr.V.I. Kleiner for the synthesis of PVCH and Dr. F.P. Cuperus (ATO-Agrotechnology, The Netherlands) for the porous PPO samples. The CONTIN program was kindly provided by Prof. R.B. Gregory. 

Using a GWBASIC program the experimental data were converted into ASCII-format, enabling their off-line analysis by the CONTIN program. The latter is a very... 

The increase of also followed from the perfectly monomodal dis number-, weight- or the polydispersity of a ber-average diameter average value increases From the calculate also concluded that o different solutions, ea Only when the standa mean value, did the fit From table 1 it fo CONTIN program were analysis range 1.1 -whi pies- the mean diameter remarkably constant upo... 

In order to obtain as realistic simulated data as possible, noise was superimposed according to a subroutine of the CONTIN program. The influence of the noise level was investigated using simulated data corresponding to a Gaussian particle size distribution (50 0.1... 

On the other hand, the results of the CONTIN program seemed to be less sensitive to the noise level provided this was below 0.005 higher values resulted in an underestimated weight-average diameter as well as a largely overestimated width of the distribution. 

Keeping account of the fact that a noise level of 0.0002 matches the analytical data, it was concluded that the CONTIN program yielded the most accurate distributions. ... 

Fig. 15.10. Distribution functions of LBN 66-lysozyme complex in 0.10 M NaCl obtained by CONTIN program from the autocorrelation functions at different pH (from top to bottom) 8.07, 8.45, 8.96, 9.62 and 10.09. (from Ref. [38])...

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