Dear Andrea,

Sorry. I will do take care of it in future. thanks

regards
Mahendra

Andrea Lini escribis:

> Dear all,
>         please avoid sending attachments to the whole list (1500
> people....) irregardless of their size.
> Use the file repository or send the files only to the interested parties.
> Thanks!
>
> Andrea Lini
> (listowner)
>
> >Dear Colleagues,
> >
> >I don t know whether I should continue on this matter or not. It
> >looks that there are
> >some who are interest in knowing it. In my opinion, too, the
> >Isogeochem Server is a
> >good opportunity to discuss our viewpoints and improve our
> >understanding with the
> >comments of others. Let me write first that I am a regular reader of
> >GCA and it
> >publishes excellent material. Of course, it is well established. My
> >comments were only
> >that the reviewers should put more attention when a mistake had been
> >pointed out.
> >People at least I use the information published there as granted.
> >
> >I worked out the problem using the activity approach. The data are
> >given in the
> >attached file. I use  Error and Trail method  to solve a non-linear
> >equation. I do it
> >in excel without writing any programming code. I don t think that anyone is
> >interested in that. The basis mistake in the reply by Halas et al.
> >(GCA, 64, 575-576,
> >2000) was that their equation 5 should be K3=a(H)a(OH)/a(H2O). The
> >values are given
> >for their system (10 g Na2CO3+CO2 from 1g of Na2CO3). Again, there
> >could be small
> >differences if you use different constants. I tried to use the same
> >constants as were
> >given by Halas et al. I did the calculation without re-check. So,
> >there could be some mistakes. I think it could be better if Halas et
> >al. change
> >equation 5 and re-calculate the parameters.
> >
> >Recently, we have started a project to study rainwater acidity
> >around geothermal
> >systems. We observed that it was really difficult to measure pH of
> >pure water like
> >rainwater with a pH-meter (rainwater characterization is based on pH
> >around the world).
> >Similarly there are problems in measuring pH of highly
> >acidic or alkaline (more in case of alkaline) waters. (we are
> >working to understand this).
> >Additionally, the IAEA has
> >conducted three interlab calibrations (Giggenbach, IAEA-TECDOC-641, Vienna,
> >p.439-456, 1989 and two are very recent). If you look these reports,
> >you will find
> >that there is some improvement in the analysis after 10 years; but
> >the quality of analysis
> >of
> >especially SiO2, HCO3 and CO3 is far bellow the expectations. That
> >is different topic
> >how to improve it. But the results indicate that in my viewpoint one
> >should not
> >design a fundamental experiment (like in discussion) where there is need of
> >correcting isotopic measurements with chemical analysis. As I tried
> >to explain it in
> >my comments. The calculated  ratio of HCO3:CO3 is 18:82. So there is
> >need of correcting the
> >HCO3 contribution. One can calculate the propogation of error in
> >their isotopic data due to
> >the error in the chemical analysis.
> >
> >Secondly, the partial pressure of CO2 in vapor phase is very low
> >(much less than
> >10^-4 bars). If you are extracting 10 micromoles, you can calculate
> >how much volume
> >should be of the experimental vessel and how the vapor phase CO2 can
> >be extracted
> >only without changing its isotopic composition. The amount of water
> >vapor will be
> >much higher than that of CO2. Check the steam tables. When you
> >condense this vapor
> >some part of CO2 will get dissolved in the water. So there will be
> >some fractionation
> >in this process, too. So, there are many points one has to consider
> >for this work. I
> >do agree that some thing is better than nothing. This way the
> >calculated values (with
> >spectroscopic data) could be more accurate than the experimentally
> >measured.  The
> >measurement of isotopic
> >fractionation for CO2(g) and carbonate is a challenging subject.
> >Definitely, it is
> >hard job to work on this type of problems. So, we should do
> >encourage the people who are
> >working such types of problems. My comments are just some suggestions,
> >which may be considered during their work.
> >
> >Best regards
> >
> >Mahendra
> >
> >
> >
> >Attachment converted: GigaBook:calFnl.xls (XLS4/XCEL) (00036526)