View Full Version : creating water with known IOPs
John Hedley
May25-04, 01:31 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>I am working on a software model to calculate the light field in water\nwith suspended particulate matter. I would like to set up some lab\nexperiments to assess the accuracy of the model. What would be very\nuseful to me is if there were some material which could be added to\npure water which would effect the inherent optical properties in a known\nway. I\'m imagining some kind of powder with a known scattering phase\nfunction and scattering co-efficient in water, so by introducing this\nmaterial in varying conc entrations I could predict the IOPs of the\nwater without having to measure them.\n\nI\'m not looking for amazing accuracy levels and a cheap and readily\navailable material would be a bonus.\n\nAny suggestions much appreciated,\n\nJohn Hedley\n\nMarine Spatial Ecology Lab\nSchool of Biological Sciences\nHatherly Laboratory\nUniversity of Exeter\nPrince of Wales Road\nExeter\nEX4 4PS\nUnited Kingdom\nhttp://www.ex.ac.uk/msel\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>I am working on a software model to calculate the light field in water
with suspended particulate matter. I would like to set up some lab
experiments to assess the accuracy of the model. What would be very
useful to me is if there were some material which could be added to
pure water which would effect the inherent optical properties in a known
way. I'm imagining some kind of powder with a known scattering phase
function and scattering co-efficient in water, so by introducing this
material in varying conc entrations I could predict the IOPs of the
water without having to measure them.
I'm not looking for amazing accuracy levels and a cheap and readily
available material would be a bonus.
Any suggestions much appreciated,
John Hedley
Marine Spatial Ecology Lab
School of Biological Sciences
Hatherly Laboratory
University of Exeter
Prince of Wales Road
Exeter
EX4 4PS
United Kingdom
http://www.ex.ac.uk/msel
Uncle Al
May26-04, 05:12 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>\nJohn Hedley wrote:\n>\n> I am working on a software model to calculate the light field in water\n> with suspended particulate matter. I would like to set up some lab\n> experiments to assess the accuracy of the model. What would be very\n> useful to me is if there were some material which could be added to\n> pure water which would effect the inherent optical properties in a known\n> way. I\'m imagining some kind of powder with a known scattering phase\n> function and scattering co-efficient in water, so by introducing this\n> material in varying conc entrations I could predict the IOPs of the\n> water without having to measure them.\n>\n> I\'m not looking for amazing accuracy levels and a cheap and readily\n> available material would be a bonus.\n\nKOWN scattering function. That\'s the rub! Fumed silica is a\npossiblity. You\'d need the size distribution and a way to reliably\ndisaggregate the microspheres (e.g., ultrasonication).\n\nYou can purchase 1-100 micron-radiused essentially monodisperse\npolymer latex used for calibration, intrinsic or fluorescent-dyed,\ne.g.,\n\nGoogle\nlatex spheres calibration 1980 hits\npolystyrene latex spheres 3540 hits\npolystyrene latex spheres calibration 812 hits\n\n<http://www.brumleysouth.com/calibration_standards.php>\n<http://www.brumleysouth.com/static/free_standards.php3>\n<http://www.laddresearch.com/.../Polystyrene_Latex_Spheres/polystyrene_latex_spheres.html>\n<http://www.2spi.com/catalog/standards/microspheres.shtml>\nhttp://www.erpt.org/ptf/partstds.htm\n\nDuke Scientific, other bio-suppliers.\n\nStarting from the small end, you can buy monodisperse spherical or\nellipsoidal dendrimers, e.g., polyacrylamide dendrimers. The\ninitiating core determines the overall shape when surface density\nmaxes out (hence automatic monodispersivity). The water-soluble\nmolecules are usually constructed by Michael addition of alkene\nconjugated to carbonyl.\n\nColloidal monodisperse perfect little spheres are nice to calculate.\nIf you want a messier case, you can precipitate colloidal magnetite\nand related ferrites\n\nJournal of Chemical Education,\n76(7) 943 (1999)\n56(10) 693 (1979)\n53(9) 560 (1976)\n41(1) 41 (1964)\n39(11) 566 (1962)\n\nGoogle\nferrofluid synthesis 713 hits\nferrofluids synthesis 885 hits\naqueous ferrofluid synthesis 287 hits\naqueous ferrofluids synthesis 335 hits\n\nhttp://www.ferrofluidics.com/\n\nIn-between you have detergent micelles whose size and size\ndistribution is determined by concentration and temp. You can puff\nthem up if you like: Sodium dodecyl benzenesulfonate will dissolve\nbenzene in water to give you micelles with cores filled with the\nhydrocarbon. Gemini surfactants give micelles at amazingy low\nconcentrations. Optical studies on detergents from lab cleaners to\nbile salts abound. They are furiously boring - a blizzard of data, a\nsurfeit of theory, and a paucity of understanding.\n\nAdd homogenized milk to water.\n\nJury-rigged monodisperse suspension: a single kind of pollen in\nwater. Conifers in spring time will give you pounds of pollen.\nLycopodium is violently hydrophobic. A little detergent will help,\nbut detergent micelles also scatter light.\n\nTalcum powder, flour, corn starch... and beware swelling over time by\nprogressive hydration.\n\n--\nUncle Al\nhttp://www.mazepath.com/uncleal/qz.pdf\nhttp://www.mazepath.com/uncleal/eotvos.htm\n(Do something naughty to physics)\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>John Hedley wrote:
>
> I am working on a software model to calculate the light field in water
> with suspended particulate matter. I would like to set up some lab
> experiments to assess the accuracy of the model. What would be very
> useful to me is if there were some material which could be added to
> pure water which would effect the inherent optical properties in a known
> way. I'm imagining some kind of powder with a known scattering phase
> function and scattering co-efficient in water, so by introducing this
> material in varying conc entrations I could predict the IOPs of the
> water without having to measure them.
>
> I'm not looking for amazing accuracy levels and a cheap and readily
> available material would be a bonus.
KOWN scattering function. That's the rub! Fumed silica is a
possiblity. You'd need the size distribution and a way to reliably
disaggregate the microspheres (e.g., ultrasonication).
You can purchase 1-100 micron-radiused essentially monodisperse
polymer latex used for calibration, intrinsic or fluorescent-dyed,
e.g.,
Google
latex spheres calibration 1980 hits
polystyrene latex spheres 3540 hits
polystyrene latex spheres calibration 812 hits
<http://www.brumleysouth.com/calibration_standards.php>
<http://www.brumleysouth.com/static/free_standards.php3>
<http://www.laddresearch.com/.../Polystyrene_Latex_Spheres/polystyrene_latex_spheres.html>
<http://www.2spi.com/catalog/standards/microspheres.shtml>
http://www.erpt.org/ptf/partstds.htm
Duke Scientific, other bio-suppliers.
Starting from the small end, you can buy monodisperse spherical or
ellipsoidal dendrimers, e.g., polyacrylamide dendrimers. The
initiating core determines the overall shape when surface density
maxes out (hence automatic monodispersivity). The water-soluble
molecules are usually constructed by Michael addition of alkene
conjugated to carbonyl.
Colloidal monodisperse perfect little spheres are nice to calculate.
If you want a messier case, you can precipitate colloidal magnetite
and related ferrites
Journal of Chemical Education,
76(7) 943 (1999)
56(10) 693 (1979)
53(9) 560 (1976)
41(1) 41 (1964)
39(11) 566 (1962)
Google
ferrofluid synthesis 713 hits
ferrofluids synthesis 885 hits
aqueous ferrofluid synthesis 287 hits
aqueous ferrofluids synthesis 335 hits
http://www.ferrofluidics.com/
In-between you have detergent micelles whose size and size
distribution is determined by concentration and temp. You can puff
them up if you like: Sodium dodecyl benzenesulfonate will dissolve
benzene in water to give you micelles with cores filled with the
hydrocarbon. Gemini surfactants give micelles at amazingy low
concentrations. Optical studies on detergents from lab cleaners to
bile salts abound. They are furiously boring - a blizzard of data, a
surfeit of theory, and a paucity of understanding.
Add homogenized milk to water.
Jury-rigged monodisperse suspension: a single kind of pollen in
water. Conifers in spring time will give you pounds of pollen.
Lycopodium is violently hydrophobic. A little detergent will help,
but detergent micelles also scatter light.
Talcum powder, flour, corn starch... and beware swelling over time by
progressive hydration.
--
Uncle Al
http://www.mazepath.com/uncleal/qz.pdf
http://www.mazepath.com/uncleal/eotvos.htm
(Do something naughty to physics)
Ralph E. Frost
May29-04, 11:53 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>"John Hedley" <J.D.Hedley@exeter.ac.uk> wrote in message\nnews:20040524125658.6209a97a.j.d.hedley@e x.ac.uk...\n> I am working on a software model to calculate the light field in water\n> with suspended particulate matter. I would like to set up some lab\n> experiments to assess the accuracy of the model. What would be very\n> useful to me is if there were some material which could be added to\n> pure water which would effect the inherent optical properties in a known\n> way. I\'m imagining some kind of powder with a known scattering phase\n> function and scattering co-efficient in water, so by introducing this\n> material in varying conc entrations I could predict the IOPs of the\n> water without having to measure them.\n>\n> I\'m not looking for amazing accuracy levels and a cheap and readily\n> available material would be a bonus.\n>\n> Any suggestions much appreciated,\n\nThis may not be any help whatsoever but you may want to look up the test\nmethod for "Turbidity". Someone in your nearby environmental engineering\ndepartment may have a copy of an older "Standard Methods" (for the\nexamination of water and wastewater), or similar text. IIRC, the old test\ninvolved filling tubes of water with some sort of standard mixture either to\ndifferent heights or in varied concentrations. Then the turbidity of a\nsample was found staring down through it to view a candle and comparing with\nthe view through different standards.\n\nGood luck on calculating it.\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>"John Hedley" <J.D.Hedley@exeter.ac.uk> wrote in message
news:20040524125658.6209a97a.j.d.hedley@ex.ac.uk.. .
> I am working on a software model to calculate the light field in water
> with suspended particulate matter. I would like to set up some lab
> experiments to assess the accuracy of the model. What would be very
> useful to me is if there were some material which could be added to
> pure water which would effect the inherent optical properties in a known
> way. I'm imagining some kind of powder with a known scattering phase
> function and scattering co-efficient in water, so by introducing this
> material in varying conc entrations I could predict the IOPs of the
> water without having to measure them.
>
> I'm not looking for amazing accuracy levels and a cheap and readily
> available material would be a bonus.
>
> Any suggestions much appreciated,
This may not be any help whatsoever but you may want to look up the test
method for "Turbidity". Someone in your nearby environmental engineering
department may have a copy of an older "Standard Methods" (for the
examination of water and wastewater), or similar text. IIRC, the old test
involved filling tubes of water with some sort of standard mixture either to
different heights or in varied concentrations. Then the turbidity of a
sample was found staring down through it to view a candle and comparing with
the view through different standards.
Good luck on calculating it.
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